Even people who eat a normal diet may not be getting enough of certain vitamins, according to researchers. The elderly and those who follow restrictive diets often face the risk of vitamin deficiency. Because low vitamin intake has been linked to a host of illnesses, Drs. Kathleen M. Fairfield and Robert H. Fletcher of Harvard Medical School in Boston, Massachusetts, recommend that everybody--regardless of age or health status--take a daily multivitamin.
In two articles in the June 19, 2002 issue of The Journal of the American Medical Association (JAMA), Fletcher and Fairfield reviewed studies published between 1966 and 2002 that investigated the links between vitamin intake and diseases such as cancer and coronary heart disease.
For example, studies have shown that taking the B-vitamin Folic Acid early in pregnancy can help prevent certain birth defects, while others have suggested Folic Acid may cut the risk of certain cancers and heart disease.
Other vitamins, such as vitamin E, have been found to reduce cancer risk when consumed at recommended levels, and vitamin D plus calcium supplements have been shown to decrease the risks of bone loss and fracture in the elderly.
Fletcher pointed out that most Americans--except those who follow what he described as a "super-perfect" diet--likely do not get enough of certain vitamins in their diets and would benefit from multivitamins, as well. A recent survey showed that only 20% to 30% of Americans consume at least five servings of fruits and vegetables per day, the recommended amount.
The evidence promoting the benefits of various vitamins is relatively new, Fletcher explained, so doctors may not yet be aware of it. Furthermore, vitamins are considered to be somewhat of an alternative therapy and some doctors have "this prejudice against anything that's not very orthodox," Fletcher stated.
As people age, they also become less able to absorb some vitamins from their diets, and research has suggested that people who drink alcohol may need extra folic acid. In addition, Fletcher said, some physicians may not understand the importance of vitamin deficiency and may fail to recommend multivitamins.
Fletcher and Fairfield point out that excessive vitamin doses can have adverse effects--including higher-than-recommended vitamin A intake during pregnancy, which is linked to certain fetal anomalies.
Journal of the American Medical Association 2002;287:3116-3126, 3127-3129.