Multiple Choice: How To Pick A Multivitamin

Nutrition Action Healthletter, April, 2000 by Bonnie Liebman

1. Look for 100 percent of ten vitamins plus some vitamin K. Our Best Bites had at least 100 percent of the DV for vitamins A, B-1 (thiamin), B2 (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.)

2. Get a minimum of minerals. 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.

3. Consider taking calcium and selenium separately. 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 (see p. 8).

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 (see p. 8).

4. Avoid excesses. 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.

MULTI V. MULTI

Every multi in this chart (we didn't look at prenatal or kids' formulas) provides at least 100 percent of the Daily Value (DV) for vitamins A, B-1, B-2, niacin, B-6, B-12, C, D, E, and folic acid. Each also has no more than 15,000 IU of beta-carotene, 18 mg of iron, 500 mg of phosphorus, and 200 mg of vitamin B-6.

To be a Best Bite, the multi also has to provide at least 25 mcg of vitamin K, 120 mcg of chromium, 100 mg of magnesium, 2 mg of copper, and 15 mg of zinc. Our circles show which multis had enough of each.