Nutrition Action Healthletter
Center for Science in the Public InterestApril 2000 — U.S. Edition 
How to

Updated Version
January 2003 (PDF)

 Who says Americans can’t think for themselves?

   For decades, health experts have issued platitudes like “you don’t need vitamins if you eat a balanced diet.” Yet an estimated 40 percent of Americans take a supplement, and it’s most likely to be a multivitamin/mineral. They’re no fools.

   It makes sense to get roughly the Daily Values for most vitamins and minerals just in case you don’t get them from food. That’s especially true for women because, on average, they eat less food than men.

   What’s more, many people run short on some key nutrients, possibly raising their risk of heart disease or birth defects (folic acid), weakened bones (vitamin D), or irreversible nerve damage (vitamin B-12).

   Of course, you can’t expect a supplement to make up for a lousy diet. Vitamins or no vitamins, you still have to eat enough fruits and vegetables, beans, whole grains, and low-fat dairy, poultry, and fish. And you still have to limit fatty meats and dairy products, pastries, commercially fried foods, and sweets.

   But a healthy diet and a supplement may be the best of both worlds. The question is which supplement... or supplements?

   It’s not as simple as taking 100 percent of the DV for everything. We already get too much of some nutrients, and some others won’t fit into a multi (unless you have to take six a day). Here’s how to sort out the good from the not-so-good multis.

Our Best Bites had at least 100 percent of the DV for vitamins A, B-1 (thiamin), B-2 (riboflavin), B-6, B-12, C, D, E, folic acid, and niacin. The over-50 crowd should look for a multi with 25 micrograms (mcg) of vitamin B-12, which is about four times the DV.

   Those minimums shouldn’t be hard to find. But many supplements—including most by brands like KAL, Natrol, Puritan’s Pride, Schiff, and Solaray—supply little or no vitamin K, which may help strengthen bones. Our Best Bites had more than 30 percent of the DV for K. If your diet is rich in vegetables—especially leafy green ones—you don’t need vitamin K in your multi. (Note: if you take blood-thinners like Coumadin, tell your doctor before taking any vitamin K. It may alter the dose of Coumadin you need.)

Our Best Bites had 100 percent of the DV for zinc and copper (fairly easy to find) and chromium (tougher to find) because there is some evidence that Americans don’t get enough of those minerals.

   We didn’t require 100 percent of the DV for magnesium for one good reason: it wouldn’t fit into a single pill. (More-than-one-a-days may appeal to some, but they’re typically more expensive.) Best Bites could get by with only 25 percent of the DV for magnesium.

We didn’t require the DV for calcium or selenium. Like magnesium, that much calcium wouldn’t fit into a single pill, and it’s easy to find a separate calcium supplement that has the right dose.

   It’s worth taking selenium separately because we couldn’t find a multi with 200 mcg of the same high-yeast selenium that appeared to reduce the risk of lung, colon, and prostate cancer (so far, in only a single—but compelling—study). Any form of selenium may turn out to be as good, but so far, no one knows. The form of selenium used in the study is SelenoExcell.

Our Best Bites had no more than 500 mg of phosphorus (we already get too much from our food), 200 mg of vitamin B-6 (higher doses may cause reversible nerve damage), and 15,000 IU of beta-carotene (more may raise the risk of lung cancer in smokers).

   Iron is more complicated, because there is no amount that’s right (or wrong) for everyone. No Best Bite had more than the DV (18 mg). But many people—men and postmenopausal women, who don’t menstruate—should look for zero to 10 mg to lower the risk of iron overload and (although the evidence is still weak) possibly heart disease and cancer. Iron in supplements may also cause constipation.

Nutrition Action Healthletter Subscribe Today! Customer Service