It Pays To Take Your Vitamins

After 20 years, the Journal of the American Medical Association (JAMA) has completely reversed its policy and is now encouraging all adults to take at least one multivitamin a day. Jeffrey Blumberg, a professor of nutrition at Tufts University, visits The Early Show on Monday to help put this in perspective.

Dr. Robert Fletcher and Dr. Kathleen Fairfield of Harvard University wrote the new guidelines for JAMA in two articles. The first one looks at findings from published articles from 1966 through Jan. 11, 2002 about vitamins in relation to chronic diseases. And the second is their recommendation based on the information they reviewed.

Blumberg says that it is significant that JAMA, a highly respected and conservative journal, is changing its policy. This new guideline will encourage physicians and clinicians to talk to their patients about taking vitamins.

Doctors Fletcher and Fairfield write that the North American diet is basically sufficient to prevent extreme vitamin deficiency diseases such as scurvy, pellagra and beriberi. However, they report, "insufficient vitamin intake is apparently a cause of chronic diseases. Recent evidence has shown that suboptimal levels of vitamins (below standard), even well above those causing deficiency syndromes, are risk factors for chronic diseases such as cardiovascular disease, cancer and osteoporosis. A large proportion of the general population is apparently at increased risk for this reason."

The body of evidence they reviewed showed that taking insufficient levels of vitamins B6 and B12 increases the risk for a person developing cardiovascular disease, neural tube defects and colon and breast cancer. Low levels of vitamin D contribute to osteoporosis and fractures. Low levels of the antioxidant vitamins (A, E and C) can potentially increase the risk for several chronic diseases.

Doctors Fletcher and Fairfield confirm that Americans are not consuming enough nutrients in their diet. The researchers reported that there wasn't enough evidence to recommend tailoring vitamin intake according to age, sex and physical activity. However, they did recommend that doctors talk to their patients about using vitamins and that women in their childbearing years take folic acid and avoid taking too much vitamin A.

Most multivitamin brands are very similar because they all have at least 100 percent of the daily-recommended value of all vitamins (except vitamin K). The articles say, "Many so-called multivitamins also often contain other food supplements such as minerals and herbs. The amount of calcium in multivitamins is typically between 40 and 60 mg, well below the generally recommended dose of 1000 to 1500 mg."

The researchers write that the only argument for taking more than one multivitamin a day applies to the elderly and women who might become pregnant.

"The recommended intake for vitamins B12 and D in the elderly is closer to 2 times the dietary reference intake, the article says. "For women who might become pregnant, folate at 800 mg. is appropriate." But Blumberg doesn't like the idea of the elderly taking more than one multivitamin a day.

"I disagree because older people are more sensitive to toxicity in vitamin A and you shouldn't double the dose,” he says. “There are in fact multivitamins that are formulated for older adults. You will find they have less iron and more vitamin D and some have more folic acid." Blumberg considers people to be elderly who are 70 years and older.

In regard to taking megavitamins, which Blumberg says is sometimes referred to anything with more than 5 times the Recommended Dietary Allowances (RDA), he says that it's beneficial for people with certain conditions to take them. But they should talk to their doctor first.

Since there are literally hundreds of multivitamin brands on the market, Blumberg suggests picking a branded product that you trust with an expiration date and that is formulated at 100 percent of the daily value. “Just look down the list. If it says 90 percent for some and over 100 for others, that's ok.” And he says that it's important to take a multi-vitamin with a meal to get the best absorption.