Which Vitamins Should I Take?

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Deficiencies of vitamins and important minerals have been observed in almost a third of elderly people. Often their dietary habits slip and they fail to eat balanced meals regularly. Multiple drug regimens may prevent absorption of some vitamins. Elderly people, particularly if they are not exposed to sunlight, may be deficient in vitamin D. They also may have low levels of important B vitamins. (Older adults showing signs of dementia should be checked for B12 deficiencies as well as other disorders causing mental disturbances.) One study reported that the immune systems of elderly people may benefit from higher levels of vitamin E than the daily recommended dosage. It should be noted, however, that metabolism slows down as a person ages, and in elderly people it takes the liver longer to eliminate drugs and vitamins from the body. The effect of some vitamin supplements, therefore, may be intensified. Dosage levels of vitamin A, for instance, which might be harmless in a younger adult, could be toxic in an elderly patient. Nevertheless, experts are increasingly recommending extra vitamin and mineral supplements for older people.

Vitamin A and Provitamin A Carotenoids (E.g., Beta Carotene)

Benefits

Essential for growth, bone development, night vision, reproduction, and healthy skin.

Recommended daily allowance (RDA) or dietary reference intake (DRI)

(mcg = micrograms, mg = milligrams, IU = international units)

Vitamin A RDA and Upper Limit (when toxicity is risk) are the following:

For children: 1000 IU ages one to three (upper limit is 2000 IU); 1333 IU ages four to eight (upper limit is 3000 IU); and 2000 IU for nine to 13 (upper limit is 5665 IU).

For nonpregnant women: 2330 IU ages 14 through adulthood. (Upper limit is 9335 IU for ages 14 to 18 and 10,000 IU for women over 19.)

For pregnant women: 2500 IU for pregnant women under 18; 2565 IU for pregnant women over 19. (Upper limit is 9335 IU for ages 14 to 18 and 10,000 IU for women over 19. It should be noted that some experts recommend 8000 IU as the upper limit during pregnancy.)

For nursing women: 4000 IU for nursing mothers under 18; 4335 IU for nursing mothers over 19. (Upper limit is 9335 IU for ages 14 to 18 and 10,000 IU for women over 19.)

For men: 3000 IU ages 14 to 18; 3000 IU for ages 19 and above. (Upper limit is 10,000 IU.)

Note: In determining the daily Vitamin A allowance, experts also take note of provitamins, such beta carotene, that convert to vitamin A. Some experts recommend 3 to 6 mg of beta-carotene.

Vitamin A is also now being measured with a new unit called the Retinol Activity Equivalent (RAE or RE). One RE is equal to 1 mcg. Retinol is the most active form of vitamin A and it is also converted in the liver from carotenoids. One RE is equal to 12 mcg of beta-carotene or 24 mcg of alpha-carotene or beta-cryptoxanthin).

Foods containing the vitamin

Animal products, such as liver, dairy products, eggs, and fish liver oil. Provitamin A carotenoids are also found in dark red, green, and yellow vegetables. Requires some dietary fat to be absorbed.

Effects of deficiencies

Skin disorders and eye damage. In less developed countries severe deficiencies cause blindness in 250,000 children each year. Diets low in vitamin A may also increase the risk of developing cancer. Low dietary intake of vitamin A has been associated with impaired lung function in children.

People at risk for deficiencies

Preschool children and any child with inadequate intake of protein, calories, and zinc. Iron deficiency may also impair metabolism of vitamin A.

People with serious disorders in the intestine, liver or pancreas, such as cystic fibrosis, steatorrhea, biliary obstruction, cirrhosis, and others.

Vegans (vegetarians who do not eat eggs and dairy). Such individuals should be sure to have plenty of deep-colored fruits and vegetables.

People who abuse alcohol. It should be noted, however, that people with alcoholism may be at risk for vitamin A deficiency, but a combination of high-dose vitamin A and alcohol may cause toxic effects in the liver.

Note: Healthy adults usually have a years store of vitamin A in the liver, so temporary nutritional deficiencies or problems with fat absorption are unlikely to cause serious vitamin A deficiency problems.

Toxicities

Very toxic when taken in high-dose supplements for long periods of time.

Symptoms of overdose include dizziness, nausea, vomiting, headache, skin damage, mental disturbances, and, in women, infrequent periods.

Can affect almost every part of the body, including eyes, bones, blood, skin, central nervous system, liver, and genital and urinary tracts. Severe toxicity can cause blindness and may even be life threatening. In children, chronic overdose can cause fluid on the brain and as well as adult complications. High consumption of vitamin A may also increase the risk of gastric cancer and the risk of osteoporosis and fractures in both men and women.

Important Note: Pregnant women who take amounts not much higher than RDA levels increase the risk for birth defects in their children. Liver damage can occur in children who take RDA-approved adult levels over prolonged periods of time or in adults who take as little as five times the RDA-approved amount for seven to ten years.

B Vitamins: General Information

Vitamin B1 (thiamin)

Benefits

The B vitamins have a wide and varied range of functions in the human body. Most B vitamins are involved in the process of converting blood sugar into energy.

Essential for converting blood sugar into energy and is involved in metabolic activities in nerves, heart, and muscles and in the production of red blood cells.

Recommended daily allowance (RDA) or dietary reference intake (DRI)

(mcg = micrograms, mg = milligrams, IU = international units)

RDA is 1.2 mg per day for men and 1.1 mg for women.

Foods containing the vitamin

Best source is pork and good sources are dried fortified cereals, oatmeal, corn, nuts, cauliflower, and sunflower seeds. Supplements for people with normal diets and health are unnecessary.

Effects of deficiencies

Deficiencies are uncommon in the US , but when they occur, they usually involve several B vitamins, since many of them come from the same food groups.

Severe vitamin B1 deficiency is known as beriberi. Can cause visual disturbances, paralysis, staggering, loss of sensation in the legs and feet, psychosis, and congestive heart failure.

People at risk for deficiencies

Alcohol interferes with these vitamins, and some of the physical and mental problems that alcoholics experience may be attributed to a deficiency of B vitamins. Elderly people are also at risk for deficiencies because of inadequate diets and potential interference with B-vitamin absorption by medications. Deficiencies can occur in severely malnourished people or in those receiving long-term dialysis or intravenous feeding. Vegetarians may be at risk.

See general vitamin B description.

Toxicities

Because the B vitamins are water-soluble and eliminated in the urine, toxic reactions from oral administration of most of them are extremely rare. (Exceptions are niacin and B6.) It should be noted that substances known as B15 (pangamic acid) and B17 (laetrile) are neither vitamins nor nutrients; both chemicals are highly dangerous and have no proven nutritional or health value.

No toxic effects have been reported from thiamin.

B Vitamins

Vitamin B2 (riboflavin)

Vitamin B3 (niacin) also known as nicotinic acid

Vitamin B5 (Pantothenic Acid)

Benefits

Important in the production of energy.

Helps break down blood sugar for energy. Acts as a vasodilator, widening blood vessels and increasing blood flow. May be prescribed for improving cholesterol levels.

Important for metabolism of fats, carbohydrates, and proteins, as well as production of steroid hormones and other important chemicals.

Recommended daily allowance (RDA) or dietary reference intake (DRI)

(mcg = micrograms, mg = milligrams, IU = international units)

DRI is 1.7 mg.

DRI is 20 mg.

Adequate intake (AI) is 4 to 7 mg.

Foods containing the vitamin

Liver, dried fortified cereals, dairy products, fish. Some dark green vegetables. Supplements for people with normal diets and health are unnecessary.

Mackerel, swordfish, chicken, veal, dried fortified cereals, pork, salmon, and beef liver. Supplements are unnecessary in people with normal health and diets.

Whole grains, beans, milk, eggs, and liver. Supplements are unnecessary in people with normal health and diets.

Effects of deficiencies

Deficiencies affect the skin and mucous membranes and can cause cracks on the lips or corners of the mouth, eczema of the face and genitals, a burning sensation on the tongue, eye irritation. May contribute to anemia when iron levels are low and contribute to elevated levels of homocysteine, a heart risk factor.

Deficiency causes pellagra; symptoms can include eczema, intestinal and stomach distress, depression, headache, thinning of the hair, and excess saliva production.

Deficiency is unlikely except in company with other B vitamin deficiencies. Symptoms include abdominal distress, burning sensation in the heels, and sleep problems.

People at risk for deficiencies

See general vitamin B description.

Alcoholics and any malnourished persons.

Alcoholics and any malnourished persons.

Toxicities

Until recently, no toxic effects had been reported even from large doses of riboflavin. However, one study indicated that high consumption of vitamin B2 might increase the risk of stomach cancer. More research is needed. (In the same study, vitamins B1, B3, and B6 were protective.)

Even mildly high doses of niacin can cause hot flushing of the face and shoulders, headache, itchiness, and stomach problems. Some report heart disturbances and temporarily lowered blood pressure. Large doses may produce ulcers, gout, diabetes, and liver damage, which are usually reversed when high doses are discontinued.

Although no toxicity has been reported in humans, high dosages have caused liver damage in rats.

B Vitamins

Vitamin B6 (pyridoxine)

Vitamin B12 (cobalamin)

Benefits

Has an effect on over 60 proteins in the body, importantly, those that play a role in the nervous system, in red and white blood cell production, and in heart disease.

Essential for the production of blood cells, manufacturing genetic material, and for healthy functioning of the nervous system.

Recommended daily allowance (RDA) or dietary reference intake (DRI)

(mcg = micrograms, mg = milligrams, IU = international units)

RDA is 1.3 mg in adults under 50 and 1.7 mg for older men and 1.5 for older women. (Some experts recommend 3 to 6 mg for people who need heart protection.) Upper limit is 100 mg for adults.

RDA is 2.4 mcg in men and nonpregnant women, 2.6 mcg in pregnant women, and 2.8 mcg in nursing mothers.

Foods containing the vitamin

Meats, oily fish, poultry, whole grains, dried fortified cereals, soybeans, avocados, baked potatoes with skins, watermelon, plantains, bananas, peanuts, and brewers yeast.

The only natural dietary sources are animal products, including meats, dairy products, eggs, and fish (clams and oily fish are very high in B12). Like other B vitamins, however, B12 is added to commercial dried cereals.

Effects of deficiencies

Increased levels of homocysteine, associated with heart disease and possibly Alzheimer's disease. Skin problems and nervous system disorders, including impaired memory and concentration. Increased risk for kidney stones.

Note: People who have been taking more than 50 mg for some time and stop suddenly are at risk for a so-called rebound deficiency. When people stop, they should taper off slowly.

Deficiencies elevate homocysteine, a possible risk factor for heart disease and Alzheimer's disease.

May cause severe depression, memory loss, instability, disorientation, and decreased reflexes, and possibly hearing loss.

Children who are deficient may experience growth failure. Deficiencies in pregnant and breast-feeding women may cause neurologic harm in their offspring.

A genetic defect that causes vitamin B12 deficiencies is responsible for pernicious anemia, a serious disorder, which must be treated with injections of vitamin B12 or else neurologic damage may occur.

People at risk for deficiencies

Alcoholics and any malnourished person. In rare cases, infants are born unable to metabolize pyridoxine; in such cases, seizures or convulsions can occur and vitamin B6 must be administered.

Alcoholics and any malnourished persons. Evidence suggests deficiencies may be caused by Helicobacter pylori (H. pylori) bacteria (a cause of ulcers). The elderly may have trouble absorbing natural vitamin B12 and require supplements. Vegetarians are at higher risk for deficiencies.

Toxicities

Very high doses can cause nerve damage with symptoms of instability and numbness in the feet and hands, which may be permanent in some cases. Of specific concern are possible adverse effects on nerve development in the offspring of pregnant women who take large doses, such as for morning sickness. Pyridoxine also reduces the effects of L-dopa, the drug used for Parkinsons disease.

There is no evidence of toxicity with this vitamin.

B Vitamins

Biotin (a B vitamin)

Choline (a B vitamin)

Folate, or Folic Acid, its synthetic form (a B vitamin)

Benefits

Involved in the production of amino acid proteins and fatty acids.

Essential for fetal brain development and for learning and memory.

Important for many metabolic processes in the body. It is used in the manufacturing of neurotransmitters (chemical messengers in the brain), in protecting the heart, and for synthesizing genetic materials (DNA) in the cells. It may improve blood flow.

Recommended daily allowance (RDA) or dietary reference intake (DRI)

(mcg = micrograms, mg = milligrams, IU = international units)

There is no DRI for biotin; some experts suggest 30-100 mcg.

RDA 425 mg for nonpregnant women, 450 mg for pregnant women, and 550 mg for nursing women.

Supplements may be folate (natural) or folic acid (synthetic). Folic acid is nearly twice the potency of folate.

DRI is 400 mcg (.4 mg) of folate for the general population.

Some experts recommend 400 mcg of folic acid for heart protection; although one study suggested 800 mcg (.8 mg) a day is necessary to reduce homocysteine levels.

Women who are planning to be pregnant should certainly take 400 mcg of folic acid before conception, during pregnancy, and while nursing.

Foods containing the vitamin

Dietary sources are eggs, milk, liver, mushrooms, bananas, tomatoes, whole grains, nuts, and brewers yeast. Also produced by bacteria in the intestines.

Peanuts, eggs, cauliflower, and meats, especially liver.

Avocado, bananas, orange juice, cold cereal, asparagus, fruits, green leafy vegetables, dried beans and peas, and yeast. Folic acid supplements are now added to commercial grain products.

Effects of deficiencies

Deficiencies are almost unheard of.

Low levels during pregnancy increase risk of birth defects in newborns.

As with vitamins B6 and B12, deficiencies elevate homocysteine, which may increase the risk for heart disease, and possibly Alzheimer's disease. Low levels during pregnancy increase risk of birth defects in newborns. Deficiencies can also cause depression and megaloblastic anemia and impair concentration, memory, and hearing.

People at risk for deficiencies

Alcoholics, malnourished persons, people with conditions that disturb the small intestine, people taking certain drugs, particularly methotrexate. Other risk factors for deficiency: high-dose aspirin, smoking, treatment for seizures, taking oral contraceptives.

Toxicities

Excessive doses can cause intestinal problems, and there is also some concern that high doses can be carcinogenic.

Low potential for toxicity. Some link between high doses and central nervous system disorders, zinc deficiency, and seizures in epileptics. This risk appears to be low, but results indicate that megadoses should be avoided. High amounts in the elderly may mask symptoms of vitamin B12 deficiencies.

Vitamin C (Ascorbic Acid)

Benefits

Vitamin C is a water-soluble vitamin. Acts as an antioxidant (reduces harm from damaging chemical processes in the body). Essential for the production of collagen, the basic protein in bones, cartilage, tendons, and ligaments. May help boost the immune system.

Recommended daily allowance (RDA) or dietary reference intake (DRI)

(mcg = micrograms, mg = milligrams, IU = international units)

DRI is 75 mg (women) and 90 mg (men). (Smokers need an additional 35 mg.)

Foods containing the vitamin

Citrus fruits and juices, papayas, hot chili peppers, bell peppers, broccoli, potatoes, kale, red cabbage, cauliflower, cantaloupe, sweet potatoes, and Brussels sprouts. Note: Orange juice is the most important source of vitamin C in the US , with frozen juice being the best source of the vitamin.

Effects of deficiencies

Scurvy is the primary deficiency disease. Affects most body tissues, particularly bones, teeth, and blood vessels. Early symptoms include tiredness, weakness, irritability, weight loss, and vague muscle aches. Later symptoms are bleeding gums, wounds that wont heal, rough skin, and wasting away of the muscles. Deficiencies may contribute to periodontal disease and gallstones. Low dietary intake of vitamin C has been associated with impaired lung function in children. Low intake may also increase lead levels in the blood.

People at risk for deficiencies

Deficiency has been uncommon in the US , usually occurring in the elderly, alcoholics, cancer patients, and some food faddists. Surprisingly, however, studies now suggest that as many as 16% of middle-aged Americans, with the highest risk in smokers and middle aged men, are deficient in vitamin C. High doses of aspirin taken over a long period of time can interfere with vitamin C.

Toxicities

Tolerable upper limit is 2000 mg/day. High doses may cause headaches and diarrhea. Long-term high doses may increase risk for kidney stones. Ascorbic acid increases iron absorption so people with blood disorders, such as hemochromatosis, thalassemia, or sideroblastic anemia, should avoid high doses. Large doses may also thin blood and interfere with anticoagulant medications, blood tests used in diabetes, and stool tests. Rebound scurvy can occur after abrupt withdrawal from long-term large doses. This may affect infants or pregnant women who withdraw suddenly from high doses.

Vitamin D

Benefits

Vitamin D is actually a single term for several hormones that are stored mainly in the liver and also in fat and muscle tissue. It is essential for the absorption of calcium into the bone and for normal bone growth.

Recommended daily allowance (RDA) or dietary reference intake (DRI)

(mcg = micrograms, mg = milligrams, IU = international units)

RDA is 200 IU (5 mcg) per day for children and most adults, 400 IU (10 mcg) for people between ages 50 and 60, and 600 IU (15 mcg) for those over 70 who do not have sufficient exposure to sunlight. Breast fed infants may need supplements.

How the Body Obtains the vitamin

Manufactured in the body from a chemical reaction to the ultraviolet radiation in sunlight. It is found in a few food sources, including vitamin D fortified milk, fatty fish, egg yolk, and liver. Note: some milk products (such as yogurt and skim milk) may have little vitamin D.

Effects of deficiencies

Softening of the bones caused by low amounts of calcium and phosphorous (called rickets in children and osteomalacia in adults). Also increases the risk for hip fractures in postmenopausal women. Associated with a higher risk for prostate cancer and breast cancer risk.

Muscle disease.

People at risk for deficiencies

Older people, particularly if they live in the North, who are underexposed to sunlight. Obesity may also increase risk. There is some concern, in fact, that vitamin D deficiency may be a growing problem in the US among younger adults as sunscreen use becomes widespread. Individuals at highest risk for vitamin D deficiency are those who assiduously avoid the midday sun, wear protective clothing, regularly use sunscreen, and have dark skin. Exposure to sunlight for about 15 to 20 minutes at mid-morning or mid-afternoon three times a week is recommended for most people who live in temperate climates.

Toxicities

Vitamin D is very toxic in high doses. In infants, daily amounts higher than 1000 IU can cause mental and growth retardation, kidney failure, and death. In children and adults, daily amounts over 50,000 IU can cause weakness, anorexia, vomiting, diarrhea, and mental changes. Prolonged use of megadoses can cause calcification of soft tissue and life-threatening kidney failure. Low-calcium diets and withdrawal from the vitamin can usually reverse the side effects except for kidney failure.

Vitamin E (Tocopherol or Tocotrienol)

Vitamin K

Benefits

A fat-soluble antioxidant vitamin that helps prevent cell membrane damage and may inhibit oxidation of LDL cholesterol (a process that increases its harmful effects on arteries).

The most important function of vitamin K is its role in blood clotting and prevention of bleeding. The vitamin also contributes to maintaining healthy bones and healing fractures.

Recommended daily allowance (RDA) or dietary reference intake (DRI)

(mcg = micrograms, mg = milligrams, IU = international units)

RDA is 15 mg (22 IU) for all adults, including pregnancy women. 19 mg (28 IU) for nursing mothers. (Supplements should be taken along with some oil or fat to be absorbed.)

Vitamin E is composed of 8 compounds (four tocopherols and four tocotrienols). Vitamin E is most often available as supplements of dl alpha tocopherol (a synthetic form).

Other vitamin E compounds may prove to be more active than the standard synthetic supplement. They include natural vitamin E, called d-alpha- or RRR-alpha-tocopherol succinate (VES). Other vitamin E compounds of interest are tocotrienol and beta and gamma tocopherol. Supplements that contain a combination of some of these forms may be most beneficial.

RDA is 60 to 65 micrograms (women) and 70 to 80 micrograms (men).

Foods containing the vitamin

Vegetable oils (particularly wheat germ oil), sweet potatoes, turnip greens, mangos, avocados, nuts, sunflower seeds, and soybeans.

Tocotrienol (a possibly beneficial form) is found in natural tropical oils. Palm oil sold in the US is refined and does not contain tocotrienol.

Best dietary sources are canola oil, cruciferous vegetables, and soybean oil. Good sources are beef liver, bran, and olive oil.

Also produced by bacteria in the intestines.

Effects of deficiencies

Deficiencies have not been established.

Easy bruising, bleeding. May increase the risk of hip fractures in women.

People at risk for deficiencies

Low-birth weight infants.

People with medical problems that impair fat absorption, such as Crohn's disease, cystic fibrosis, steatorrhea, liver diseases (such as cirrhosis).

People with abetalipoproteinemia, a rare genetic disorder that impairs fat metabolism.

Deficiency may occur in patients who have problems absorbing fats, such as those with cirrhosis, people who are on long-term antibiotic therapy, or who are taking other medications, including cholestyramine, Dilantin, and phenobarbital. Some evidence suggests that more young people may be deficient than previously believed.

Toxicities

Upper level recommended is 1,500 IU of alpha tocopherol. Large doses may cause bleeding problems, particularly in people taking anti-clotting medications. Some research now indicates that vitamin E, like other antioxidants, may have pro-oxidant and damaging effects.

Allergic-type responses, including rash and itching, to high doses have been reported. Those who are taking Coumadin, an anticoagulant, should not take vitamin K without consulting a physician.

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