Disease: Vitamin and Calcium Supplements

    What are vitamins, and why are they important?

    There are six basic types of nutrients that are considered essential to life: proteins, carbohydrates, fats, vitamins, minerals, and water. These nutrients are needed for your body to function properly, and your diet is the source of them. Vitamins and minerals are considered micronutrients because they are needed in smaller quantities than the macronutrients (protein, carbohydrates, and fat). Micronutrients do not provide calories. When your body does not absorb an adequate amount of any of the micronutrients, diseases can occur. It's important to understand what your nutritional needs are and how to achieve them.

    Vitamins are broken down into two categories: water-soluble and fat-soluble. Water-soluble vitamins dissolve in water. Leftover amounts are not stored and will leave your body through your urine. For this reason, you must consume them on a continuous basis. The water-soluble vitamins are the B vitamins and vitamin C. Fat-soluble vitamins dissolve in fat, not water. These vitamins need dietary fat in order to be better absorbed in the small intestines. They are then stored in the liver and fatty tissues (adipose tissues) and can accumulate to toxic levels when consumed in excess quantities. The fat-soluble vitamins are vitamins A, D, E, and K.

    Recommendations for essential nutrients are provided in the Dietary Reference Intakes (DRIs) developed by the Institute of Medicine of the National Academies. Dietary Reference Intakes is the general term for a set of reference values used for planning and assessing nutrient intake for healthy people. There are three important types of DRI reference values; Recommended Dietary Allowances (RDA), Adequate Intakes (AI), and Tolerable Upper Intake Levels (UL). The RDA is set to meet the nutrient requirements for the average daily intake of nearly all healthy individuals in each age and gender group. When there is insufficient data to set an RDA for a nutrient, an AI is set. AIs meet or exceed the amount needed to maintain an adequate nutritional state in nearly everyone of a specific age and gender group. Some nutrients can cause health problems when consumed in excessive quantities. The UL was set to provide the maximum daily intake that is unlikely to result in adverse health effects. Numerous health conditions, however, can impact your nutritional needs. A registered dietitian or physician can help you better determine your needs based upon your overall health and condition.

    Calcium

    What is calcium, and what does it do?

    Most people know that calcium is needed for strong bones, but it's also needed to help blood vessels and muscles contract and expand, to send messages through the nervous system, and to secrete hormones and enzymes. This is the most abundant mineral in your body and makes up 1%-2% of adult human body weight. Over 99% of it is stored in bones and teeth with the rest stored in blood, muscle, and other tissues.

    How much do you need to consume?

    There is a great deal of concern over Americans not meeting the recommendations for calcium intake. The recommendations for calcium are listed as an Adequate Intake:

    AgeAdequate Intake for Calcium0 to 6 months*210 mg from breast milk 315 mg from formula7 to 12 months*270 mg from breast milk 335 mg from formula1 to 3 years500 mg4 to 8 years800 mg9 to 13 years1,300 mg14 to 18 years1,300 mg19 to 50 years1,000 mg51+ years1,200 mg

    *Breast milk has been shown to have a higher rate of calcium absorption than formula, so calcium requirements are higher for formula-based diets. Calcium needs during pregnancy and lactation do not change from ages 14 to 50.

    What are sources of calcium?

    Calcium is found in a variety of foods, but the amount that your body absorbs varies. Oxalic acid and phytic acid both interfere with the absorption of calcium. Foods rich in oxalic acid are spinach, rhubarb, sweet potatoes, and beans. Foods rich in phytic acid are unleavened bread, nuts, seeds, and raw beans. You will absorb some of the calcium in these foods, but not as much as you would from foods that do not contain oxalic acid or phytic acid. For example, calcium absorption from dried beans is about half of what you absorb from milk, and calcium absorption from spinach is about one-tenth of that absorbed from milk. There is no need to omit these foods from your diet. Instead, consume a variety of calcium-rich foods throughout the day.

    According to the USDA Nutrient Database, the calcium content of some common foods is shown below:

    FoodAmountCalcium ContentCheese, cheddar1 ½ oz shredded306 mgCollards, frozen, boiled1 cup357 mgCottage cheese, 1% milk fat1 cup138 mgMilk, nonfat1 cup306 mgPowdered milk, nonfat1 tbsp50 mg-100 mgSalmon, canned with bones3 oz181 mgSardines, canned in oil, with bones3 oz324 mgSoy milk1 cup93 mgTofu, soft, made w/calcium sulfate½ cup138 mgYogurt, plain, low-fat1 cup415 mgYogurt, fruit, low-fat1 cup245 mg-385 mg

    You can also increase your calcium intake by

    • adding nonfat powdered milk to cereals (hot and cold), soups, gravy, baked goods, or casseroles,
    • using nonfat milk in place of water in recipes (pancakes, pudding, hot cereals, and mashed potatoes), and
    • having yogurt dips for vegetable and chips.
    Do I need to take a calcium supplement?

    A well-balanced diet can be enough to reach your recommended intake of calcium. When diet is not enough, a calcium supplement may be necessary. In the case of calcium supplements, more is definitely not better. Calcium absorption is most efficient when the dose is 500 mg or less. This means that taking 1,000 mg at one time is less effective than taking two separate doses of 500 mg.

    Calcium exists in nature combined with other chemicals. These compounds are what you will find in supplements and include calcium carbonate, calcium phosphate, calcium lactate, and calcium citrate. Calcium carbonate is the most common one because it is inexpensive and convenient. People who have decreased stomach acid (for example, older adults and those who take antacids) are better off taking calcium citrate. According to the National Osteoporosis Foundation, "Calcium supplements prepared from unrefined oyster shell, bone meal, or dolomite may contain lead or other toxic metals," so you need to pay attention to the source of calcium in your supplement.

    Calcium supplements may cause gas, bloating, and/or constipation. There may be options to help relieve this. You can try spreading out dosages of the supplement throughout the day, try taking it with food, try a different brand, or speak with your doctor or pharmacist for assistance.

    What happens if I do not have enough calcium?

    Bone is a living tissue that constantly breaks down and builds back up. Up until around the age of 30, consuming an adequate amount of calcium with enough physical activity ensures that your body builds more bone than it breaks down. The majority of adult bone mass is acquired by age 18 in girls and 20 in boys. After that, breakdown typically exceeds the amount of bone being built. For this reason, it's essential to maximize bone stores when it's still possible. The amount that you lose after age 30 will be impacted by genetics, ethnicity, physical activity level, sex hormone levels, diet, and gender. You can replace what you lose with the foods you eat and your activity level, but you can't increase how much you store. When bone mass drops and there is a deterioration of bone tissue, osteoporosis can occur. Osteoporosis causes bones to be susceptible to fractures. Depending on the severity of the damage, bones can break from a minor fall, or in severe cases, from sneezing.

    Other factors can put you at risk for low calcium levels.

    Amenorrhea: Research has shown that young women who do not get their period due to anorexia nervosa have reduced net calcium absorption, higher urinary calcium excretion, and a lower rate of bone formation in comparison to those who menstruate regularly. Reduced calcium retention and lower bone mass have also been seen in exercise-induced amenorrhea.

    Lactose intolerance: Many people find that consuming dairy products causes bloating, gas, cramping, and/or diarrhea. This is often from your body's inability to break down the lactose found in dairy foods. Lactose is the sugar that naturally occurs in these foods. Avoiding dairy foods can put you at risk for calcium deficiency. Fortunately, there are things that you can do to help with these symptoms. The first thing is to try to consume smaller amounts of dairy foods. Studies have shown that lactose intolerance is dose-dependent and different people have the intolerance at different levels of severity. When this doesn't work, you can purchase dairy products that have the lactose broken down for you. Lactaid products have taken the lactose and broken it up so that your body does not have to.

    Is there such a thing as too much calcium?

    The Tolerable Upper Limit (UL) for calcium for children and adults ages 1 year and older is 2,500 mg/day. Excessively high intakes would have to come from supplements alone or supplements in combination with dietary sources. The dangers of excessive consumption are impaired kidney function, hypercalcemia, and decreased absorption of other minerals (iron, zinc, magnesium, and phosphorus). Calcium has been shown to interfere with iron absorption. It's best to take the recommended amounts of calcium separate from iron-containing foods or supplements.

    Calcium also has the potential to interact with medications by decreasing the absorption of the medication. Some affected medications are digoxin, fluoroquinolones, levothyroxine, antibiotics in tetracycline family, and phenytoin. Your doctor and pharmacist can provide further information about this.

    Vitamin D

    What is it, and what does it do?

    Vitamin D is probably most well-known for being the "sunshine vitamin." The ultraviolet rays from sunlight striking the skin, causing vitamin D to be made. It can also be found in food and supplements. This is one of the four fat-soluble vitamins. That means that it's stored in the body's fatty tissue and can build up to toxic levels with excessive consumption. The current thinking, however, is that the potential toxicity of vitamin D has been exaggerated in the past and it is safe overall.

    The major function of vitamin D is to maintain optimal blood levels of calcium and phosphorus. Studies have shown that it provides protection from hypertension, cancer, osteoporosis, type 1 diabetes, and several autoimmune diseases.

    How much do I need to consume?

    The recommendations for vitamin D are listed as an Adequate Intake in micrograms (mcg) and International Units (IU):

    AgeVitamin D0-12 months10 mcg (400 IU)1 to 13 years15 mcg (600 IU)14 to 18 years15 mcg (600 IU)19 to 50 years15 mcg (600 IU)50 to 71 years

    15 mcg (600 IU)

    71+ years

    20 mcg (800 IU)

    What are sources of vitamin D?

    The sunshine vitamin got its name from the fact that the sun helps our body produce vitamin D. The concern about skin cancer has caused many people to avoid unprotected exposure to the sun. Fortunately, it is possible to consume enough vitamin D in your diet, so it is not necessary to risk the dangers of skin cancer by exposing yourself to the sun. For those who do rely on the sun as one of their sources, there are many factors that will impact how much you need. The season, time of day, cloud coverage, smog, amount and SPF of sunscreen, geographic latitude, and melanin content of your skin are all possible barriers. It can take anywhere from five to 30 minutes of sun on unexposed skin between the hours of 10 a.m. and 3 p.m. at least twice a week.

    The foods that naturally contain vitamin D are seafood, mushrooms, and egg yolks. Dietary sources of vitamin D are:

    FoodAmountVitamin D ContentBluefish3 oz415 IUCatfish3 oz425 IUCod liver oil1 teaspoon450 IUEgg yolk1 whole25 IUMackerel3 oz395 IUMilk, vitamin D fortified1 cup100 IUMushrooms, Chanterelle2 oz50 IUMushrooms, Shitake2 oz55 IUOysters3 oz545 IUSalmon, farmed3 oz275 IUSalmon, wild3 oz1,000 IUSardines, canned in oil1 ¾ oz230 IUShrimp3 oz120 IUTuna, bluefin3 oz170 IUTuna, canned in water3 oz135 IUDo I need to take a vitamin D supplement?

    When diet is not enough, you may need to take a supplement to help you reach the desired intake of vitamin D. As you will see, vitamin D can be toxic at high levels, so the goal is to reach the appropriate level, not exceed it.

    The two primary types of vitamin D supplements are vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). Most experts believe that vitamin D3 is the ideal choice for these reasons:

    • Vitamin D3 is the most potent form, it's more stable on the shelf, and it's less toxic than D2.
    • Vitamin D3 is the one that is synthesized when the sun hits your skin, so it's considered to be the most natural.
    • Most of the research that has been done on vitamin D and its health benefits has used vitamin D3.
    What happens if I don't have enough vitamin D?

    You can have blood tests done to determine if you are deficient in vitamin D. Your 25(OH)D level will be measured. Most experts agree that 25(OH)D level below <20 ng/mL represents vitamin D deficiency, whereas a 25(OH)D level below 20 ng/mL is an indication of vitamin D deficiency.

    Research has shown strong relationships between lower rates of chronic diseases and higher levels of vitamin D. The most well-known disease related to vitamin D deficiency is rickets. Rickets is the disease that was found to be cured by consuming cod liver oil in the early 20th century. Rickets causes soft, weak bones in children, resulting in skeletal deformities (bowed legs), impaired growth, bone pain, dental problems, and fragile bones. Unfortunately, rickets has still been seen in children not being fed an adequate amount of vitamin D. In adults, vitamin D deficiency can lead to osteoporosis and osteomalacia (both are conditions of weakened bones).

    There are several other factors that can contribute to a deficiency in vitamin D:

    Age: People over 50 years old have a decreased ability to synthesize and absorb vitamin D. This occurs regardless of the amount of sun exposure time.

    Medical conditions: Vitamin D requires fat for absorption, so anyone with a medical condition that reduces the ability to absorb dietary fat can be at risk for a deficiency. It is important to have vitamin D levels monitored in people with conditions such as Crohn's disease, celiac disease, cystic fibrosis, pancreatic enzyme deficiency, and surgical removal of any part of the stomach or intestines.

    Obesity: Research has shown lower vitamin D concentrations in overweight and obese individuals. One possible reason for this is that vitamin D gets absorbed by fat tissue and is not easily absorbed in the bloodstream.

    Sun exposure: The ultraviolet rays from the sun have served as a source of vitamin D over the years. Due to the danger of skin cancer, many people have cut back on their exposure to the sun and have begun using sunscreen when they are being exposed, so this can contribute to lower levels if adjustments are not made to compensate for this loss via dietary sources and/or supplements.

    Skin pigmentation: There is more melanin in darker-skinned individuals. Melanin blocks the ultraviolet rays and interferes with vitamin D synthesis.

    Are there any dangers to consuming too much vitamin D?

    Consuming excessive amount of vitamin D can pose health problems. This is most likely to occur from taking supplements or high doses of cod liver oil. There is no danger of vitamin D toxicity from sun exposure. Symptoms of toxicity can be nausea, poor appetite, weakness, weight loss, constipation, and high blood levels of calcium. A blood level of over 200 ng/mL for vitamin D, measured as 25(OH)D, can be potentially toxic. For this reason, the tolerable upper intake (UL) for vitamin D has been set at 2,000 IU (50 mcg) per day for ages 1 and above. The UL for birth to 12 months is 1,000 IU (25 mcg) per day.

    Folic Acid

    What is folic acid, and what does it do?

    Folic acid is the man-made form of folate, a naturally occurring B vitamin. Because it's a water-soluble vitamin, it cannot be stored in the body so it needs to be supplied on a continuous basis.

    Folic acid helps form and maintain new cells. It is needed to make red blood cells and for the metabolism of homocysteine. It helps produce DNA, and it helps prevent changes in DNA that may lead to cancer.

    How much do I need to consume?

    The Recommended Dietary Allowances (RDA) for folate are expressed in a term called Dietary Folate Equivalent (DFE). The naturally occurring folate is absorbed differently than the man-made folic acid, so the DFE was developed to help account for these differences. One DFE is equal to 1 microgram (mcg) of food folate and 0.6 mcg of folic acid from supplements and fortified foods.

    The RDA for folate:

    Age Males and Females Pregnancy Lactation 1 to 3 years 150 mcg N/A N/A 4 to 8 years 200 mcg N/A N/A 9 to 13 years 300 mcg N/A N/A 14 to 18 years 400 mcg 600 mcg 500 mcg 19+ years 400 mcg 600 mcg 500 mcg

    There is insufficient information to establish an RDA for folate for infants. In this case, an Adequate Intake (AI) has been established:

    Age Males and Females 0 to 6 months 65 mcg 7 to 12 months 80 mcg What are sources of folic acid?

    Folate can be found naturally in many foods, including fruits, leafy green vegetables, and dried beans. Folic acid is added to certain foods because of regulations published by the Food and Drug Administration in 1996. These foods are considered enriched because the folic acid is replacing the folate that was lost during processing. Some common folic acid-enriched foods are cereals, breads, pasta, rice, flours, and cornmeal. Folic acid can also be added to foods and beverages in addition to the nutrients that they already contain. These foods are considered fortified with folic acid. In 1998, the folic acid fortification program was initiated to help Americans reach their folic acid recommendations.

    Food sources of folate and folic acid are:

    Food Amount Folate/Folic Acid Content Asparagus, cooked 4 spears 85 mcg Avocado, sliced, raw ½ cup 45 mcg Banana, raw 1 medium 20 mcg Beef liver 3 oz 185 mcg Broccoli, chopped, frozen, cooked ½ cup 50 mcg Broccoli, raw 2 spears 45 mcg Cantaloupe, raw ¼ medium 25 mcg Great Northern beans ½ cup 90 mcg Green peas, frozen, cooked ½ cup 50 mcg Papaya, raw, cubes ½ cup 25 mcg Rice, white, enriched, cooked ½ cup 65 mcg Spinach, frozen, cooked ½ cup 100 mcg Spinach, raw 1 cup 60 mcg Tomato juice 6 oz 35 mcg Do I need to take a folic acid supplement?

    The goal is to consume a balanced diet that provides your daily folate needs. The folate-enriched and -fortified foods make this much easier to accomplish. When you have a medical condition that interferes with the amount that you can consume, if you are unable to absorb all of what you consume, if your diet is limited, or if you have an increased need for folate, a supplement would be the best option. It is recommended that women who may become pregnant take 400 mcg of folic acid from fortified foods and/or dietary supplements along with consuming a well-balanced diet.

    Another possible reason to take a supplement would be for heart protection. There are some studies that have shown that folic acid can lower homocysteine levels by up to 25%. High blood levels of homocysteine can damage the inner surface of blood vessels, promote blood clotting, accelerate atherosclerosis, and thus lead to heart attacks and strokes.

    What happens if I don't have enough folic acid?

    One very severe consequence of not getting enough folic acid is the possibility of neural tube defects during pregnancy. Neural tube defects usually develop in the first 28 days of pregnancy. Many women do not know that they are pregnant during this time and are not monitoring their folic acid intake. For this reason, it's a good idea to make sure that you have an adequate daily intake before trying to conceive.

    A deficiency in folate can lead to megaloblastic (or macrocytic) anemia. It may also cause poor growth, gray hair, glossitis, mouth ulcers, diarrhea, and peptic ulcers. Studies have shown that low blood folate levels are associated with high blood homocysteine levels. High blood levels of homocysteine can damage the inner surface of blood vessels, promote blood clotting, accelerate atherosclerosis, and thus lead to heart attacks and strokes.

    There are medical conditions and medications that can increase the need for folate, increase its excretion, or interfere with its utilization:

    • pregnancy and lactation,
    • liver disease,
    • kidney dialysis,
    • malabsorption,
    • alcohol abuse,
    • triamterene,
    • barbiturates,
    • anticonvulsant medications,
    • sulfasalazine,
    • metformin, and
    • methotrexate.

    It's best to speak with your doctor if any of these applies to you.

    Is there such a thing as too much folic acid?

    There is no Tolerable Upper Limit (UL) set for natural sources of folate found in food.

    There are UL set for folate from fortified foods and supplements.

    Age Males and Females Pregnancy Lactation 1 to 3 years 300 mcg N/A N/A 4 to 8 years 400 mcg N/A N/A 9 to 13 years 600 mcg N/A N/A 14 to 18 years 800 mcg 800 mcg 800 mcg 19+ years 1,000 mcg 1,000 mcg 1,000 mcg

    Going above the UL increases your risk for adverse health effects.

    Vitamin E

    What is it, and what does it do?

    Vitamin E represents a family of eight fat-soluble antioxidant vitamins. Each form has its own function. Alpha-tocopherol is the most important E vitamin in humans. Vitamin E is involved in maintaining cell integrity, and it protects vitamin A and essential fatty acids from oxidation in the body cells.

    How much do I need to consume?

    The Recommended Dietary Allowances (RDA) for vitamin E is based on the alpha-tocopherol form. The recommendations below are in milligrams (mg) and International Units (IU). You can use the milligrams when looking at the content in food and the International Units when looking at the content in supplements.

    The RDA for vitamin E is:

    Age Males and Females Pregnancy Lactation 1 to 3 years 6 mg (9 IU) N/A N/A 4 to 8 years 7 mg (10.5 IU) N/A N/A 9 to 13 years 11 mg (16.5 IU) 15 mg (22.5 IU) 19 mg (28.5 IU) 14 + years 15 mg (22.5 IU) 15 mg (22.5 IU) 19 mg (28.5 IU)

    There is insufficient information to establish an RDA for vitamin E for infants. In this case, an Adequate Intake (AI) has been established:

    Age Males and Females 0 to 6 months 4 mg (6 IU) 7 to 12 months 5 mg (7.5 IU) What are sources of vitamin E?

    There are many foods rich in vitamin E. The most common ones are fortified cereals, green leafy vegetables, vegetable oil, eggs, and nuts. The content of vitamin E in food is based on the alpha-tocopherol content:

    Food Amount Vitamin E Alpha-tocopherol Almonds, dry roasted 1 oz 7.4 mg Broccoli, frozen, cooked ½ cup 1.2 mg Corn oil 1 tablespoon 1.9 mg Egg 1 large 5.3 mg Kiwi, no skin 1 medium 1.1 mg Mango, raw ½ cup sliced 0.9 mg Peanut butter, smooth style, fortified 2 tablespoons 4.2 mg Safflower oil 1 tablespoon 4.6 mg Soybean oil 1 tablespoon 1.3 mg Spinach, frozen, cooked ½ cup 1.6 mg Spinach, raw 1 cup 0.6 mg Sunflower oil 1 tablespoon 5.6 mg Sunflower seed kernels, dry roasted 1 oz 6.0 mg Wheat germ oil 1 tablespoon 20.3 mg Do I need to take a vitamin E supplement?

    Most research shows that we do not consume an adequate amount of vitamin E, but a deficiency is rare. According to the USDA, the intake of vitamin E by women 19 to 50 years is less than 90% of the RDA. The average consumption for American adults is 7 to 9 mg compared to the recommended 15 mg. There is, however, a possibility that we are consuming more than we think. Many people under-report their fat intake, so there is a chance that you are reaching your recommended amount of vitamin E if you do consume a large amount of the oils that contain it. Unfortunately, the amount of oil that it would take to reach the recommendations is high, and with that comes a lot of calories. It would be best to consume a variety of the foods that contain vitamin E with limited amounts of oil and take a supplement for what you are missing.

    There is some evidence that vitamin E supplements help protect against heart disease, but this evidence is controversial. In a study of approximately 90,000 nurses, the incidence of heart disease was 30%-40% lower in those with the highest intake of vitamin E from supplements, not from food. This study was looking at what happened to these nurses without any kind of intervention. The studies that gave people vitamin E supplements have not seen any protection against heart disease. The reason for the difference is still unclear, so there is more research being done to determine what role vitamin E plays in protecting against heart disease. At this time, the American Heart Association does not recommend antioxidant vitamins -- including vitamin E -- for preventing cardiovascular disease.

    Some cancers develop from oxidation damage to DNA. In the Alpha-Tocopherol Beta Carotene (ATBC) study, scientists found a 32% reduction in the incidence of prostate cancer among subjects taking alpha-tocopherol supplements compared to those not taking the vitamin. However, several studies have found no benefit of vitamin E in preventing lung and breast cancers. More randomized controlled trials are needed to determine the effect of vitamin E on cancer risks.

    Alzheimer's disease is a degenerative brain disease with progressive loss of mental capacity, thought in part to be due to oxidation. High doses of alpha-tocopherol supplementation in one study slowed the progression of Alzheimer's disease. Although these results are promising, large-scale placebo-controlled prospective trials will be required to determine the role of a-tocopherol supplementation in the treatment of Alzheimer's disease.

    When purchasing vitamin E supplements, you will see that they are often sold as alpha-tocopheryl acetate. This form of alpha-tocopherol protects its ability to function as an antioxidant. A "DL" on the label means that it's the synthetic form and is about half as active as the natural form, which is listed as "D."

    What happens if I don't have enough vitamin E?

    Dietary vitamin E deficiency is common in developing countries and among people with fat-malabsorption diseases. The main symptoms are hemolytic anemia and neurologic deficits.

    Is there such a thing as too much vitamin E?

    Vitamin E can act as an anticoagulant, which means that it can increase the risk of bleeding problems. This means that people taking warfarin (Coumadin) should not take vitamin E supplements without their doctor's approval. The Tolerable Upper Limit (UL) was set at the highest dose unlikely to result in bleeding problems.

    Learn more about: Coumadin

    There are UL set for vitamin E:

    Age Males and Females Pregnancy Lactation 1 to 3 years 200 mg (300 IU) N/A N/A 4 to 8 years 300 mg (450 IU) N/A N/A 9 to 13 years 600 mg (900 IU) N/A N/A 14 to 18 years 800 mg (1,200 IU) 800 mg (1,200 IU) 800 mg (1,200 IU) 19+ years 1,000 mg (1,500 IU) 1,000 mg (1,500 IU) 1,000 mg (1,500 IU)

    Vitamin A

    What is it, and what does it do?

    Vitamin A is a fat-soluble vitamin that is broken down into two categories: preformed vitamin A comes from animal foods, and provitamin A carotenoid comes from plant foods.

    Vitamin A serves many functions:

    • helps regulate the immune system to prevent and fight infections
    • helps form and maintain healthy teeth, skin, and tissues
    • produces the pigments in the retina of the eye
    • promotes good vision
    How much do I need to consume?

    The Recommended Dietary Allowances (RDA) for vitamin A are listed as International Units (IU) of Retinol Activity Equivalents (RAE). This is done to account for the different actions of both forms of vitamin A.

    RDA for vitamin A:

    Age Males Females Pregnancy Lactation 1 to 3 yrs 1,000 IU 1,000 IU N/A N/A 4 to 8 yrs 1,320 IU 1,320 IU N/A N/A 9 to 13 yrs 2,000 IU 2,000 IU N/A N/A 14 to 18 yrs 3,000 IU 2,310 IU 2,500 IU 4,000 IU 19+ 3,000 IU 2,310 IU 2,565 IU 4,300 IU

    There is insufficient information to establish an RDA for vitamin A for infants. In this case, an Adequate Intake (AI) has been established:

    Age Males and Females 0 to 6 months 1,320 IU 7 to 12 months 1,650 IU What are sources of vitamin A?

    Vitamin A can be found in animal and plant foods. The animal food sources are better absorbed and used by the body than the plant sources. There are also many foods that are fortified and enriched with vitamin A.

    The content of vitamin A in animal and plant foods (from beta-carotene):

    Food Amount Vitamin A Apricot nectar, canned ½ cup 1,651 IU Cantaloupe 1 cup cube 5,411 IU Carrot juice, canned ½ cup 22,567 IU Carrots, boiled ½ cup slices 13,418 IU Carrots, raw 1 - 7 ½ inches 8,666 IU Cheese, cheddar 1 oz 249 IU Kale, frozen, boiled ½ cup 9,558 IU Liver, beef, cooked 3 oz 27,185 IU Liver, chicken, cooked 3 oz 12,325 IU Milk, fortified skim 1 cup 500 IU Oatmeal, instant, fortified 1 cup 1,252 IU Papaya 1 cup cubed 1,532 IU Peach 1 medium 319 IU Peas, frozen, boiled ½ cup 1,050 IU Pepper, red, raw 1 ring 313 IU Spinach, frozen, boiled ½ cup 11,458 IU Spinach, raw 1 cup 2,813 IU Vegetable soup, canned 1 cup 5,820 IU Do I need to take a vitamin A supplement?

    Vitamin A is stored in the liver, so there is a supply that can be used during short-term periods when intake is not adequate to meet your needs. People with medical conditions that interfere with the absorption of vitamin A may need to take a supplement. These conditions include celiac disease, Crohn's disease, inflammatory bowel disease, and pancreatic disorders. Because vitamin A can be toxic at high levels, it's best to discuss supplements with your physician.

    What happens if I don't have enough vitamin A?

    Early vitamin A deficiency leads to impaired night vision, and advanced vitamin A deficiency can lead to corneal ulcers, xerophthalamia (dry eye), scarring, night blindness or total blindness. In developing countries, vitamin A deficiency is an important cause of blindness among children. Children with vitamin A deficiency are also more likely to develop diarrhea and respiratory infections than children who are not vitamin A deficient. Vitamin A deficiency is rare among healthy adults in the United States.

    Vitamin A deficiency can also be a problem for people with Crohn's disease, celiac disease, pancreatic disorders, and people who do not consume animal foods.

    Is there such a thing as too much vitamin A?

    When excess amounts of vitamin A are being stored in your body, the condition is called hypervitaminosis A. The harmful effects of hypervitaminosis A are birth defects, reduced bone density that may result in osteoporosis, central nervous system disorders, and liver abnormalities.

    Acute vitamin A toxicity may result from consuming very large quantities of vitamin A over a short period of time. The symptoms are nausea, vomiting, irritability, drowsiness, altered mental status, anorexia, abdominal pain, blurred vision, muscle pain with weakness, and/or headache. Elderly people and people who drink alcohol heavily are more susceptible to vitamin A toxicity.

    The Institute of Medicine states that "beta-carotene supplements are not advisable for the general population," although they also state that this advice "does not pertain to the possible use of supplemental beta-carotene as a provitamin A source for the prevention of vitamin A deficiency in populations with inadequate vitamin A."

    The Tolerable Upper Limit (UL) for vitamin A is:

    Age Males and Females Pregnancy Lactation 0 to 1 year 2,000 IU N/A N/A 1 to 3 years 2,000 IU N/A N/A 4 to 8 years 3,000 IU N/A N/A 9 to 13 years 5,610 IU N/A N/A 14 to 18 years 9,240 IU 9,240 IU 9,240 IU 19+ years 10,000 IU 10,000 IU 10,000 IU

    In the ATBC trial, subjects given beta-carotene had a higher incidence of lung cancer than subjects not given beta-carotene. The Institute of Medicine did not set ULs for carotene or carotenoids. However, the recommendation is that beta-carotene supplements are not advisable for the general population.

    Vitamin C

    What is it, and what does it do?

    Vitamin C, also known as ascorbic acid, is a water-soluble antioxidant vitamin. Vitamin C is required for the synthesis of collagen and dentin. Collagen is the structural component of blood vessels, bones, ligaments, and tendons, while dentin is the structural component of teeth. Vitamin C is also an effective antioxidant that protects proteins and genetic materials (RNA and DNA) from damage by free radicals. Vitamin C cannot be made or stored by your body, so it's important to consume a well-balanced diet containing vitamin C.

    Learn more about: ascorbic acid

    How much do I need to consume?

    There is insufficient information to establish an RDA for vitamin C for infants. In this case, an Adequate Intake (AI) has been established:

    Age Males and Females 0 to 6 months 40 mg/day 7 to 12 months 50 mg/day

    The Recommended Dietary Allowance (RDA) for vitamin C is:

    Age Males Females Pregnancy Lactation 1 to 3 years 15 mg 15 mg N/A N/A 4 to 8 years 25 mg 25 mg N/A N/A 9 to 13 years 45 mg 45 mg N/A N/A 14 to 18 years 75 mg 65 mg 80 mg 115 mg 19 + years 90 mg/day 75 mg/day 85 mg/day 120 mg/day What are sources of vitamin C?

    All fruits and vegetables contain some amount of vitamin C, so consuming a well-balanced diet with plenty of fruits and vegetables is the key.

    Food Amount Vitamin C Broccoli, cooked ½ cup 37 mg Broccoli, raw ½ cup 39 mg Brussels sprouts, cooked ½ cup 48 mg Cantaloupe ¼ medium 47 mg Cauliflower, cooked ½ cup 28 mg Grapefruit juice ¾ cup 50 mg-70 mg Green pepper, cooked ½ cup 51 mg Green pepper, raw ½ cup 60 mg Guava, raw ½ cup 188 mg Kale, cooked ½ cup 27 mg Kiwi 1 medium 70 mg Mango ½ cup 23 mg Orange 1 medium 70 mg Orange juice ¾ cup 61 mg-93 mg Papaya ¼ medium 47 mg Pineapple, raw ½ cup 28 mg Pod peas, cooked ½ cup 38 mg Red sweet pepper, cooked ½ cup 116 mg Red sweet pepper, raw ½ cup 142 mg Strawberries ½ cup 49 mg Sweet potato, canned ½ cup 34 mg Tomato juice ¾ cup 33 mg Vegetable juice ¾ cup 50 mg Do I need to take a vitamin C supplement?

    Many people believe that taking vitamin C will help prevent colds. Research has not shown this to be the case. More than 30 clinical trials that included over 10,000 participants have not found any relationship between vitamin C and a reduced risk of colds. There has been a small reduction in the duration of colds, so paying attention to your vitamin C intake once you have the cold is advisable.

    Research has shown that vitamin C enhances the absorption of iron. For this reason, anyone who needs an iron supplement is usually advised to take it with a food that is high in vitamin C or with a vitamin C supplement. Iron can be toxic at high levels, so speak with your doctor before taking any supplements.

    There is an increased need for vitamin C for individuals who smoke. There is an additional 35 mg/day requirement for smokers versus nonsmokers. This can be achieved with dietary sources or a supplement.

    What happens if I don't have enough vitamin C?

    Scurvy is a severe deficiency of vitamin C. It would be uncommon for most of us, but it can be found in someone who is malnourished. Less severe deficiencies can occur. Not consuming an adequate amount of vitamin C can lead to symptoms, including feeling weak, tired, and irritable, having dry and splitting hair, bleeding gums, rough, dry, and scaly skin, gingivitis, easy bruising, anemia, and a decreased ability to fight infection.

    Is there such a thing as too much vitamin C?

    Vitamin C is generally safe. Large doses of vitamin C may cause stomach upset and diarrhea in adults and have been reported to cause kidney stones. There is also a risk of excess iron absorption with high doses of vitamin C.

    Vitamin B12

    What is it, and what does it do?

    Vitamin B12 is needed for producing and maintaining new cells, including nerve cells and red blood cells. It is also needed to help make DNA.

    Vitamin B12 is bound to the proteins in food. Once you consume B12, the hydrochloric acid in your stomach releases the B12 from the protein. B12 then combines with a substance called intrinsic factor to be absorbed by the intestines.

    Learn more about: B12

    How much do I need to consume?

    There is insufficient information to establish an RDA for vitamin B12 for infants. In this case, an Adequate Intake (AI) has been established:

    Age Males and Females 0 to 6 months 0.4 mcg/day 7 to 12 months 0.5 mcg/day

    The Recommended Dietary Allowance (RDA) for vitamin B12 is:

    Age Males and Females Pregnancy Lactation 1 to 3 years 0.9 mcg N/A N/A 4 to 8 years 1.2 mcg N/A N/A 9 to 13 years 1.8 mcg N/A N/A 14 to 19 years 2.4 mcg 2.6 mcg 2.8 mcg 19+ years 2.4 mcg/day 2.6 mcg/day 2.8 mcg/day What are sources of vitamin B12?

    Vitamin B12 is attached to the proteins in animal foods. Breakfast cereals are fortified with vitamin B12, which is very important for people who do not consume an adequate amount of animal foods.

    Food Amount Vitamin B12 Beef, top sirloin, lean, choice, broiled 3 oz 2.4 mcg Breakfast cereals, fortified ¾ cup 6 mcg Chicken, breast, cooked ½ breast 0.3 mcg Egg 1 large 0.6 mcg Haddock, cooked 3 oz 1.2 mcg Liver, beef 1 slice 47.9 mcg Milk 1 cup 0.9 mcg Mollusks, clam 3 oz 84.1 mcg Salmon, sockeye, cooked 3 oz 4.9 mcg Trout, rainbow, farmed, cooked 3 oz 4.2 mcg Trout, rainbow, wild, cooked 3 oz 5.4 mcg Tuna, white, canned in water 3 oz 1.0 mcg Yogurt, plain, skim 1 cup 1.4 mcg Do I need to take a vitamin B12 supplement?

    Studies reveal that the majority of Americans consume an adequate amount of vitamin B12. People who do not consume meat or who have a stomach or intestinal disorder that interferes with absorption may need to take a vitamin B12 supplement. Older adults may have atrophic gastritis and may need to consume additional food sources and/or supplements. There are also some medications that can influence vitamin B12 absorption, including H2 receptor antagonists used to treat peptic ulcers, metformin, and proton pump inhibitors. Your doctor can determine your vitamin B12 levels with a blood test.

    What happens if I don't have enough vitamin B12?

    An inadequate amount of vitamin B12 can cause pernicious anemia. Signs of vitamin B12 deficiency are fatigue, constipation, weakness, loss of appetite, weight loss, and numbness and tingling in the hands and feet. You may also experience a difficulty in maintaining balance, confusion, dementia, depression, and poor memory. An excess intake of folate can mask the symptoms of B12 deficiency, so it's important to have your levels checked with blood tests if there is a concern, especially if you consume a vegetarian diet.

    Is there such a thing as too much vitamin B12?

    Currently, there is no Tolerable Upper Limit set for vitamin B12. This does not mean that consuming excessive amounts will provide any additional health benefits. It means that there is a very low potential for toxicity at high levels.

    Vitamin B6

    What is vitamin B6, and what does it do?

    Vitamin B6 is one of the water-soluble B vitamins. It comes in three forms: pyridoxine, pyridoxal, and pyridoxamine. It serves numerous functions in your body, including

    • red blood cell metabolism,
    • making hemoglobin,
    • assisting in the proper functioning of the nervous system,
    • assisting in the proper functioning of the immune system,
    • protein metabolism, and
    • synthesis of serotonin and norepinephrine.
    How much vitamin B6 do I need to consume?

    The Recommended Dietary Allowance (RDA) for vitamin B6 is:

    Age Males Females Pregnancy Lactation 1 to 3 yrs 0.5 mg 0.5 mg N/A N/A 4 to 8 yrs 0.6 mg 0.6 mg N/A N/A 9 to 13 yrs 1.0 mg 1.0 mg N/A N/A 14 to 18 yrs 1.3 mg 1.2 mg 1.9 mg 2.0 mg 19 to 50 yrs 1.3 mg 1.3 mg 1.9 mg 2.0 mg 51+ yrs 1.7 mg 1.5 mg N/A N/A

    There is insufficient information to establish an RDA for vitamin B6 for infants. In this case, an Adequate Intake (AI) has been established:

    Age Males and Females 0 to 6 months 0.1 mg/day 7 to 12 months 0.3 mg/day What are sources of vitamin B6?

    Vitamin B6 is found naturally in many foods and can also be found in foods that are fortified with it:

    Food Amount Vitamin B6 Avocado, raw, California 1 oz 0.08 mg Banana 1 medium 0.43 mg Cereal, 100% fortified ¾ cup 2 mg Chicken breast, meat only 3 oz 0.52 mg Garbanzo beans ½ cup 0.51 mg Lima beans, frozen, cooked ½ cup 0.10 mg Oatmeal, instant, fortified 1 packet 0.42 mg Peanut butter, smooth 1 tablespoon 0.09 mg Pistachio nuts, dry roasted 1 oz (47 nuts) 0.36 mg Pork loin, cooked 3 oz 0.42 mg Potato, with skin 1 medium 0.47 mg Roast beef, eye of round, cooked 3 oz 0.42 mg Salmon, Sockeye, cooked 3 oz 0.19 mg Soybeans, green ½ cup 0.05 mg Spinach, frozen, cooked ½ cup 0.14 mg Sunflower seeds, kernels 1 oz 0.23 mg Tomato juice, canned 8 oz 0.27 mg Trout, rainbow, cooked 3 oz 0.29 mg Tuna, canned in water 3 oz 0.18 mg Walnuts, English/Persian 1 oz 0.15 mg Wheat bran ¼ cup 0.18 mg Yogurt, plain, skim milk 8 oz 0.12 mg Do I need to take a vitamin B6 supplement?

    Vitamin B6 is available as pyridoxine hydrochloride in supplements. The requirements for vitamin B6 can easily be met with a well-balanced diet. When your diet is limited in variety, you may need to take a supplement. Older adults and alcoholics are people whose diets may be lacking and require supplementation. Studies have shown that supplementing with large doses of vitamin B6 can increase the immune response in critically ill patients.

    What happens if I don't have enough vitamin B6?

    In the early 1950s, an error in the manufacturing of baby formula lead to vitamin B6 deficiencies and caused seizures in the infants who were deficient in it. Other symptoms of vitamin B6 deficiency are depression, confusion, sores or ulcers on the mouth, ulcers at the corners of the mouth, confusion, and irritability.

    Is there such a thing as too much vitamin B6?

    There are no documented health problems associated with consuming vitamin B6 from food sources. There have been problems associated with excess supplementation of vitamin B6. Large doses, above 1,000 mg/day, have been shown to cause sensory neuropathy. Symptoms of this include difficulty walking and pain and numbness of the extremities. There have even been some reported cases of this with doses under 500 mg/day. Even though this is a water-soluble vitamin, limits had to be set on how much can be safely consumed.

    The Tolerable Upper Limit (UL) for vitamin B6 was set for the general population:

    Age Males and Females 1 to 3 years 30 mg/day 4 to 8 years 40 mg/day 9 to 13 years 60 mg 14 to 18 years 80 mg 19+ years 100 mg

    Calcium

    What is calcium, and what does it do?

    Most people know that calcium is needed for strong bones, but it's also needed to help blood vessels and muscles contract and expand, to send messages through the nervous system, and to secrete hormones and enzymes. This is the most abundant mineral in your body and makes up 1%-2% of adult human body weight. Over 99% of it is stored in bones and teeth with the rest stored in blood, muscle, and other tissues.

    How much do you need to consume?

    There is a great deal of concern over Americans not meeting the recommendations for calcium intake. The recommendations for calcium are listed as an Adequate Intake:

    AgeAdequate Intake for Calcium0 to 6 months*210 mg from breast milk 315 mg from formula7 to 12 months*270 mg from breast milk 335 mg from formula1 to 3 years500 mg4 to 8 years800 mg9 to 13 years1,300 mg14 to 18 years1,300 mg19 to 50 years1,000 mg51+ years1,200 mg

    *Breast milk has been shown to have a higher rate of calcium absorption than formula, so calcium requirements are higher for formula-based diets. Calcium needs during pregnancy and lactation do not change from ages 14 to 50.

    What are sources of calcium?

    Calcium is found in a variety of foods, but the amount that your body absorbs varies. Oxalic acid and phytic acid both interfere with the absorption of calcium. Foods rich in oxalic acid are spinach, rhubarb, sweet potatoes, and beans. Foods rich in phytic acid are unleavened bread, nuts, seeds, and raw beans. You will absorb some of the calcium in these foods, but not as much as you would from foods that do not contain oxalic acid or phytic acid. For example, calcium absorption from dried beans is about half of what you absorb from milk, and calcium absorption from spinach is about one-tenth of that absorbed from milk. There is no need to omit these foods from your diet. Instead, consume a variety of calcium-rich foods throughout the day.

    According to the USDA Nutrient Database, the calcium content of some common foods is shown below:

    FoodAmountCalcium ContentCheese, cheddar1 ½ oz shredded306 mgCollards, frozen, boiled1 cup357 mgCottage cheese, 1% milk fat1 cup138 mgMilk, nonfat1 cup306 mgPowdered milk, nonfat1 tbsp50 mg-100 mgSalmon, canned with bones3 oz181 mgSardines, canned in oil, with bones3 oz324 mgSoy milk1 cup93 mgTofu, soft, made w/calcium sulfate½ cup138 mgYogurt, plain, low-fat1 cup415 mgYogurt, fruit, low-fat1 cup245 mg-385 mg

    You can also increase your calcium intake by

    • adding nonfat powdered milk to cereals (hot and cold), soups, gravy, baked goods, or casseroles,
    • using nonfat milk in place of water in recipes (pancakes, pudding, hot cereals, and mashed potatoes), and
    • having yogurt dips for vegetable and chips.
    Do I need to take a calcium supplement?

    A well-balanced diet can be enough to reach your recommended intake of calcium. When diet is not enough, a calcium supplement may be necessary. In the case of calcium supplements, more is definitely not better. Calcium absorption is most efficient when the dose is 500 mg or less. This means that taking 1,000 mg at one time is less effective than taking two separate doses of 500 mg.

    Calcium exists in nature combined with other chemicals. These compounds are what you will find in supplements and include calcium carbonate, calcium phosphate, calcium lactate, and calcium citrate. Calcium carbonate is the most common one because it is inexpensive and convenient. People who have decreased stomach acid (for example, older adults and those who take antacids) are better off taking calcium citrate. According to the National Osteoporosis Foundation, "Calcium supplements prepared from unrefined oyster shell, bone meal, or dolomite may contain lead or other toxic metals," so you need to pay attention to the source of calcium in your supplement.

    Calcium supplements may cause gas, bloating, and/or constipation. There may be options to help relieve this. You can try spreading out dosages of the supplement throughout the day, try taking it with food, try a different brand, or speak with your doctor or pharmacist for assistance.

    What happens if I do not have enough calcium?

    Bone is a living tissue that constantly breaks down and builds back up. Up until around the age of 30, consuming an adequate amount of calcium with enough physical activity ensures that your body builds more bone than it breaks down. The majority of adult bone mass is acquired by age 18 in girls and 20 in boys. After that, breakdown typically exceeds the amount of bone being built. For this reason, it's essential to maximize bone stores when it's still possible. The amount that you lose after age 30 will be impacted by genetics, ethnicity, physical activity level, sex hormone levels, diet, and gender. You can replace what you lose with the foods you eat and your activity level, but you can't increase how much you store. When bone mass drops and there is a deterioration of bone tissue, osteoporosis can occur. Osteoporosis causes bones to be susceptible to fractures. Depending on the severity of the damage, bones can break from a minor fall, or in severe cases, from sneezing.

    Other factors can put you at risk for low calcium levels.

    Amenorrhea: Research has shown that young women who do not get their period due to anorexia nervosa have reduced net calcium absorption, higher urinary calcium excretion, and a lower rate of bone formation in comparison to those who menstruate regularly. Reduced calcium retention and lower bone mass have also been seen in exercise-induced amenorrhea.

    Lactose intolerance: Many people find that consuming dairy products causes bloating, gas, cramping, and/or diarrhea. This is often from your body's inability to break down the lactose found in dairy foods. Lactose is the sugar that naturally occurs in these foods. Avoiding dairy foods can put you at risk for calcium deficiency. Fortunately, there are things that you can do to help with these symptoms. The first thing is to try to consume smaller amounts of dairy foods. Studies have shown that lactose intolerance is dose-dependent and different people have the intolerance at different levels of severity. When this doesn't work, you can purchase dairy products that have the lactose broken down for you. Lactaid products have taken the lactose and broken it up so that your body does not have to.

    Is there such a thing as too much calcium?

    The Tolerable Upper Limit (UL) for calcium for children and adults ages 1 year and older is 2,500 mg/day. Excessively high intakes would have to come from supplements alone or supplements in combination with dietary sources. The dangers of excessive consumption are impaired kidney function, hypercalcemia, and decreased absorption of other minerals (iron, zinc, magnesium, and phosphorus). Calcium has been shown to interfere with iron absorption. It's best to take the recommended amounts of calcium separate from iron-containing foods or supplements.

    Calcium also has the potential to interact with medications by decreasing the absorption of the medication. Some affected medications are digoxin, fluoroquinolones, levothyroxine, antibiotics in tetracycline family, and phenytoin. Your doctor and pharmacist can provide further information about this.

    Vitamin D

    What is it, and what does it do?

    Vitamin D is probably most well-known for being the "sunshine vitamin." The ultraviolet rays from sunlight striking the skin, causing vitamin D to be made. It can also be found in food and supplements. This is one of the four fat-soluble vitamins. That means that it's stored in the body's fatty tissue and can build up to toxic levels with excessive consumption. The current thinking, however, is that the potential toxicity of vitamin D has been exaggerated in the past and it is safe overall.

    The major function of vitamin D is to maintain optimal blood levels of calcium and phosphorus. Studies have shown that it provides protection from hypertension, cancer, osteoporosis, type 1 diabetes, and several autoimmune diseases.

    How much do I need to consume?

    The recommendations for vitamin D are listed as an Adequate Intake in micrograms (mcg) and International Units (IU):

    AgeVitamin D0-12 months10 mcg (400 IU)1 to 13 years15 mcg (600 IU)14 to 18 years15 mcg (600 IU)19 to 50 years15 mcg (600 IU)50 to 71 years

    15 mcg (600 IU)

    71+ years

    20 mcg (800 IU)

    What are sources of vitamin D?

    The sunshine vitamin got its name from the fact that the sun helps our body produce vitamin D. The concern about skin cancer has caused many people to avoid unprotected exposure to the sun. Fortunately, it is possible to consume enough vitamin D in your diet, so it is not necessary to risk the dangers of skin cancer by exposing yourself to the sun. For those who do rely on the sun as one of their sources, there are many factors that will impact how much you need. The season, time of day, cloud coverage, smog, amount and SPF of sunscreen, geographic latitude, and melanin content of your skin are all possible barriers. It can take anywhere from five to 30 minutes of sun on unexposed skin between the hours of 10 a.m. and 3 p.m. at least twice a week.

    The foods that naturally contain vitamin D are seafood, mushrooms, and egg yolks. Dietary sources of vitamin D are:

    FoodAmountVitamin D ContentBluefish3 oz415 IUCatfish3 oz425 IUCod liver oil1 teaspoon450 IUEgg yolk1 whole25 IUMackerel3 oz395 IUMilk, vitamin D fortified1 cup100 IUMushrooms, Chanterelle2 oz50 IUMushrooms, Shitake2 oz55 IUOysters3 oz545 IUSalmon, farmed3 oz275 IUSalmon, wild3 oz1,000 IUSardines, canned in oil1 ¾ oz230 IUShrimp3 oz120 IUTuna, bluefin3 oz170 IUTuna, canned in water3 oz135 IUDo I need to take a vitamin D supplement?

    When diet is not enough, you may need to take a supplement to help you reach the desired intake of vitamin D. As you will see, vitamin D can be toxic at high levels, so the goal is to reach the appropriate level, not exceed it.

    The two primary types of vitamin D supplements are vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). Most experts believe that vitamin D3 is the ideal choice for these reasons:

    • Vitamin D3 is the most potent form, it's more stable on the shelf, and it's less toxic than D2.
    • Vitamin D3 is the one that is synthesized when the sun hits your skin, so it's considered to be the most natural.
    • Most of the research that has been done on vitamin D and its health benefits has used vitamin D3.
    What happens if I don't have enough vitamin D?

    You can have blood tests done to determine if you are deficient in vitamin D. Your 25(OH)D level will be measured. Most experts agree that 25(OH)D level below <20 ng/mL represents vitamin D deficiency, whereas a 25(OH)D level below 20 ng/mL is an indication of vitamin D deficiency.

    Research has shown strong relationships between lower rates of chronic diseases and higher levels of vitamin D. The most well-known disease related to vitamin D deficiency is rickets. Rickets is the disease that was found to be cured by consuming cod liver oil in the early 20th century. Rickets causes soft, weak bones in children, resulting in skeletal deformities (bowed legs), impaired growth, bone pain, dental problems, and fragile bones. Unfortunately, rickets has still been seen in children not being fed an adequate amount of vitamin D. In adults, vitamin D deficiency can lead to osteoporosis and osteomalacia (both are conditions of weakened bones).

    There are several other factors that can contribute to a deficiency in vitamin D:

    Age: People over 50 years old have a decreased ability to synthesize and absorb vitamin D. This occurs regardless of the amount of sun exposure time.

    Medical conditions: Vitamin D requires fat for absorption, so anyone with a medical condition that reduces the ability to absorb dietary fat can be at risk for a deficiency. It is important to have vitamin D levels monitored in people with conditions such as Crohn's disease, celiac disease, cystic fibrosis, pancreatic enzyme deficiency, and surgical removal of any part of the stomach or intestines.

    Obesity: Research has shown lower vitamin D concentrations in overweight and obese individuals. One possible reason for this is that vitamin D gets absorbed by fat tissue and is not easily absorbed in the bloodstream.

    Sun exposure: The ultraviolet rays from the sun have served as a source of vitamin D over the years. Due to the danger of skin cancer, many people have cut back on their exposure to the sun and have begun using sunscreen when they are being exposed, so this can contribute to lower levels if adjustments are not made to compensate for this loss via dietary sources and/or supplements.

    Skin pigmentation: There is more melanin in darker-skinned individuals. Melanin blocks the ultraviolet rays and interferes with vitamin D synthesis.

    Are there any dangers to consuming too much vitamin D?

    Consuming excessive amount of vitamin D can pose health problems. This is most likely to occur from taking supplements or high doses of cod liver oil. There is no danger of vitamin D toxicity from sun exposure. Symptoms of toxicity can be nausea, poor appetite, weakness, weight loss, constipation, and high blood levels of calcium. A blood level of over 200 ng/mL for vitamin D, measured as 25(OH)D, can be potentially toxic. For this reason, the tolerable upper intake (UL) for vitamin D has been set at 2,000 IU (50 mcg) per day for ages 1 and above. The UL for birth to 12 months is 1,000 IU (25 mcg) per day.

    Folic Acid

    What is folic acid, and what does it do?

    Folic acid is the man-made form of folate, a naturally occurring B vitamin. Because it's a water-soluble vitamin, it cannot be stored in the body so it needs to be supplied on a continuous basis.

    Folic acid helps form and maintain new cells. It is needed to make red blood cells and for the metabolism of homocysteine. It helps produce DNA, and it helps prevent changes in DNA that may lead to cancer.

    How much do I need to consume?

    The Recommended Dietary Allowances (RDA) for folate are expressed in a term called Dietary Folate Equivalent (DFE). The naturally occurring folate is absorbed differently than the man-made folic acid, so the DFE was developed to help account for these differences. One DFE is equal to 1 microgram (mcg) of food folate and 0.6 mcg of folic acid from supplements and fortified foods.

    The RDA for folate:

    Age Males and Females Pregnancy Lactation 1 to 3 years 150 mcg N/A N/A 4 to 8 years 200 mcg N/A N/A 9 to 13 years 300 mcg N/A N/A 14 to 18 years 400 mcg 600 mcg 500 mcg 19+ years 400 mcg 600 mcg 500 mcg

    There is insufficient information to establish an RDA for folate for infants. In this case, an Adequate Intake (AI) has been established:

    Age Males and Females 0 to 6 months 65 mcg 7 to 12 months 80 mcg What are sources of folic acid?

    Folate can be found naturally in many foods, including fruits, leafy green vegetables, and dried beans. Folic acid is added to certain foods because of regulations published by the Food and Drug Administration in 1996. These foods are considered enriched because the folic acid is replacing the folate that was lost during processing. Some common folic acid-enriched foods are cereals, breads, pasta, rice, flours, and cornmeal. Folic acid can also be added to foods and beverages in addition to the nutrients that they already contain. These foods are considered fortified with folic acid. In 1998, the folic acid fortification program was initiated to help Americans reach their folic acid recommendations.

    Food sources of folate and folic acid are:

    Food Amount Folate/Folic Acid Content Asparagus, cooked 4 spears 85 mcg Avocado, sliced, raw ½ cup 45 mcg Banana, raw 1 medium 20 mcg Beef liver 3 oz 185 mcg Broccoli, chopped, frozen, cooked ½ cup 50 mcg Broccoli, raw 2 spears 45 mcg Cantaloupe, raw ¼ medium 25 mcg Great Northern beans ½ cup 90 mcg Green peas, frozen, cooked ½ cup 50 mcg Papaya, raw, cubes ½ cup 25 mcg Rice, white, enriched, cooked ½ cup 65 mcg Spinach, frozen, cooked ½ cup 100 mcg Spinach, raw 1 cup 60 mcg Tomato juice 6 oz 35 mcg Do I need to take a folic acid supplement?

    The goal is to consume a balanced diet that provides your daily folate needs. The folate-enriched and -fortified foods make this much easier to accomplish. When you have a medical condition that interferes with the amount that you can consume, if you are unable to absorb all of what you consume, if your diet is limited, or if you have an increased need for folate, a supplement would be the best option. It is recommended that women who may become pregnant take 400 mcg of folic acid from fortified foods and/or dietary supplements along with consuming a well-balanced diet.

    Another possible reason to take a supplement would be for heart protection. There are some studies that have shown that folic acid can lower homocysteine levels by up to 25%. High blood levels of homocysteine can damage the inner surface of blood vessels, promote blood clotting, accelerate atherosclerosis, and thus lead to heart attacks and strokes.

    What happens if I don't have enough folic acid?

    One very severe consequence of not getting enough folic acid is the possibility of neural tube defects during pregnancy. Neural tube defects usually develop in the first 28 days of pregnancy. Many women do not know that they are pregnant during this time and are not monitoring their folic acid intake. For this reason, it's a good idea to make sure that you have an adequate daily intake before trying to conceive.

    A deficiency in folate can lead to megaloblastic (or macrocytic) anemia. It may also cause poor growth, gray hair, glossitis, mouth ulcers, diarrhea, and peptic ulcers. Studies have shown that low blood folate levels are associated with high blood homocysteine levels. High blood levels of homocysteine can damage the inner surface of blood vessels, promote blood clotting, accelerate atherosclerosis, and thus lead to heart attacks and strokes.

    There are medical conditions and medications that can increase the need for folate, increase its excretion, or interfere with its utilization:

    • pregnancy and lactation,
    • liver disease,
    • kidney dialysis,
    • malabsorption,
    • alcohol abuse,
    • triamterene,
    • barbiturates,
    • anticonvulsant medications,
    • sulfasalazine,
    • metformin, and
    • methotrexate.

    It's best to speak with your doctor if any of these applies to you.

    Is there such a thing as too much folic acid?

    There is no Tolerable Upper Limit (UL) set for natural sources of folate found in food.

    There are UL set for folate from fortified foods and supplements.

    Age Males and Females Pregnancy Lactation 1 to 3 years 300 mcg N/A N/A 4 to 8 years 400 mcg N/A N/A 9 to 13 years 600 mcg N/A N/A 14 to 18 years 800 mcg 800 mcg 800 mcg 19+ years 1,000 mcg 1,000 mcg 1,000 mcg

    Going above the UL increases your risk for adverse health effects.

    Vitamin E

    What is it, and what does it do?

    Vitamin E represents a family of eight fat-soluble antioxidant vitamins. Each form has its own function. Alpha-tocopherol is the most important E vitamin in humans. Vitamin E is involved in maintaining cell integrity, and it protects vitamin A and essential fatty acids from oxidation in the body cells.

    How much do I need to consume?

    The Recommended Dietary Allowances (RDA) for vitamin E is based on the alpha-tocopherol form. The recommendations below are in milligrams (mg) and International Units (IU). You can use the milligrams when looking at the content in food and the International Units when looking at the content in supplements.

    The RDA for vitamin E is:

    Age Males and Females Pregnancy Lactation 1 to 3 years 6 mg (9 IU) N/A N/A 4 to 8 years 7 mg (10.5 IU) N/A N/A 9 to 13 years 11 mg (16.5 IU) 15 mg (22.5 IU) 19 mg (28.5 IU) 14 + years 15 mg (22.5 IU) 15 mg (22.5 IU) 19 mg (28.5 IU)

    There is insufficient information to establish an RDA for vitamin E for infants. In this case, an Adequate Intake (AI) has been established:

    Age Males and Females 0 to 6 months 4 mg (6 IU) 7 to 12 months 5 mg (7.5 IU) What are sources of vitamin E?

    There are many foods rich in vitamin E. The most common ones are fortified cereals, green leafy vegetables, vegetable oil, eggs, and nuts. The content of vitamin E in food is based on the alpha-tocopherol content:

    Food Amount Vitamin E Alpha-tocopherol Almonds, dry roasted 1 oz 7.4 mg Broccoli, frozen, cooked ½ cup 1.2 mg Corn oil 1 tablespoon 1.9 mg Egg 1 large 5.3 mg Kiwi, no skin 1 medium 1.1 mg Mango, raw ½ cup sliced 0.9 mg Peanut butter, smooth style, fortified 2 tablespoons 4.2 mg Safflower oil 1 tablespoon 4.6 mg Soybean oil 1 tablespoon 1.3 mg Spinach, frozen, cooked ½ cup 1.6 mg Spinach, raw 1 cup 0.6 mg Sunflower oil 1 tablespoon 5.6 mg Sunflower seed kernels, dry roasted 1 oz 6.0 mg Wheat germ oil 1 tablespoon 20.3 mg Do I need to take a vitamin E supplement?

    Most res

    Source: http://www.rxlist.com

    Vitamin A is a fat-soluble vitamin that is broken down into two categories: preformed vitamin A comes from animal foods, and provitamin A carotenoid comes from plant foods.

    Vitamin A serves many functions:

    • helps regulate the immune system to prevent and fight infections
    • helps form and maintain healthy teeth, skin, and tissues
    • produces the pigments in the retina of the eye
    • promotes good vision

    Source: http://www.rxlist.com

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