Vitamins for Chronic Disease Prevention in Adults: Clinical Applications
Classic vitamin deficiency syndromes, such as scurvy or beriberi, are uncommon in Western cultures. Suboptimal levels of some vitamins may result in chronic diseases. Suboptimal levels of folic acid in conjunction with vitamins B6 and B12 are a risk factor for cardiovascular disease, neural tube defects and colon and breast cancer. Low levels of vitamin D may result in bone loss and fractures. Low levels of antioxidant vitamins A, C and E may increase the risk for several chronic diseases. Most individuals do not consume optimal amounts of all vitamins from their diet. It appears to be a prudent idea for all adults to take basic vitamin supplements. Physicians should ask patients regarding their use of vitamins in a non-threatening way. Folic acid supplementation should be recommended for women during childbearing years, and high-doses of vitamin A should be avoided during pregnancy. Large doses of fat-soluble vitamins should be avoided at any age. A recent survey showed that only 20-30% of the population actually consumed 5 daily servings of fruits and vegetables. Many of the elderly do not get sufficient amounts of vitamin D. Many individuals do not get enough folic acid, even though cereals are fortified by up to 100 mcg. Keeping food hot more than 2 hours results in a more than 10% loss of vitamin C, folate and vitamin B6. More than 30% of vitamin C and folate are lost during chilling, storage and reheating. Alcohol consumption increases folate requirements, and aging is associated with a reduction in absorption of some vitamins, such as vitamin B12. The recommended intake for vitamin B12 and vitamin D is closer to 2 times the dietary reference intake. Women who might become pregnant should take 800 mcg/day of folic acid. The authors recommend that all adults take a multivitamin daily. This is justified due to the benefits of supplementation with folate, vitamin B12, vitamin B6 and vitamin D in the prevention of cardiovascular disease, cancer and osteoporosis. It is reasonable to consider a dose of 2 ordinary multivitamins daily in the elderly, especially because of the high prevalence of suboptimal vitamin B12 and vitamin D intake. For women attempting to conceive, a multivitamin plus folic acid at 400 mcg/day is appropriate.