Multiple Choice: How To Pick A Multivitamin

Nutrition Action Healthletter, April, 2000 by Bonnie Liebman

For example, some imply that what helps someone who is severely deficient would help the problems facing average Americans. Take GNC MultiGel. It claims that vitamin A is "essential for normal vision." Yes, millions of people in developing countries go blind because they get too little vitamin A. But no, vitamin A won't lessen the vision problems facing typical Americans.

The Vitamin Shoppe Mature Female is also misleading. It has 18 amino acids that are "the building blocks of growth," according to the label. Amino acids are the building blocks of muscles, skin, and many other body parts that are made of protein. But all 18 of The Vitamin Shoppe's amino acids add up to less than half a gram of protein. Compared to the 50-gram DV, that's trivial.

You know you're looking at a structure-or-function claim when the label says: "These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease."

In contrast, some label claims--what the lawyers call "health claims"--are approved by the FDA. For example, the folate in supplements really does help prevent neural-tube birth defects, and the calcium really does help prevent osteoporosis.

HOW TO READ A VITAMIN LABEL

Here's part of the label of the best-selling multivitamin, Centrum, which is often imitated by cheaper "store brands" with names like "Central-Vite" or "Sentury-Vite." Centrum is a Best Bite for premenopausal women, but probably has too much iron for men and postmenopausal women. We use the Centrum label to explain what to look for (or avoid) in your multi.

Vitamin A. There's no need to get more than the Daily Value (5,000 IU) of vitamin A palmitate or acetate. Multis don't go above 10,000 IU to avoid increasing the risk of birth defects. Many multis also contain beta-carotene, which the body converts to vitamin A. While beta-carotene isn't toxic and doesn't cause birth defects, high doses (33,000 to 50,000 IU a day) may raise the risk of cancer in smokers. Our advice: Don't get more than 15,000 IU of beta-carotene from a pill. Instead, load up on beta-carotene-rich fruits and vegetables like cantaloupe, carrots, and sweet potatoes, which may help prevent cancer.

Vitamin D. It helps you absorb calcium. Yet many older people get too little D from their food--the major sources are milk, fatty fish (like salmon), and fortified cereals--or from sunshine, especially in the winter. The National Academy of Sciences recommends 200 IU a day for adults under 51,400 IU for those aged 51 to 70; and 600 IU for anyone over 70. Look for a multi with at least 400 IU (the DV).

Folic Acid. Look for the Daily Value (400 mcg, or 0.4 mg), to reduce the risk of birth defects (for women who could become pregnant) and possibly heart disease, stroke, or colon cancer (for everyone).

Biotin and Pantothenic Acid. Ignore. You'd have to eat a bizarre diet to run short of either.

Iron. Many children and premenopausal women are deficient, but too much can cause overload (hemochromatosis) in susceptible people. To play it safe, men and postmenopausal women should look for zero to 10 mg of iron in their multis. The DV (18 mg) is okay for children and premenopausal women, but nobody should take more unless their doctor says so. Iron supplements can also cause constipation.