Even if multivitamins won't prolong your life or keep you from getting sick, "they can still fill in the gaps if you get too little vitamins and minerals from your food," says Susan Roberts, professor of nutrition at Tufts University.
- Vitamin D. A majority of us don't get enough from our food, and the recommended use of sun screens may keep us from getting enough from sunlight.
- Folic acid. This nutrient helps protect against birth defects that can occur before a woman knows she is pregnant. About one in five women of child-bearing age don't get enough folic acid.
- Vitamin B-12. Adults over 50 have too little stomach acid to absorb the B-12 that naturally occurs in foods and therefore should look to fortified foods or supplements.
- Iron. About 15 percent of women 50 and younger are iron deficient.
- Calcium. Adults need 1,000 to 1,200 milligrams of calcium a day, and most of us don't get that much from food. Multivitamins typically have 100 to 200mg, which can help.
If you take a multivitamin, avoid cereals, energy bars, or other foods or supplements that contain 400mcg of folic acid per serving. (If they have that much, the Nutrition Facts panel on the label will list the amount of folic acid as "100% DV."
And if you're still nervous about excess folic acid (and are not at risk of becoming pregnant), take your multivitamin every other day.Selenium. I took selenium for awhile years ago for my prostate cancer based on studies showing that it could prevent some tumors in laboratory animals. But CSPI notes that "its results in people has been disappointing." And it may increase the risk of being diagnosed with diabetes. CSPI's advice: "don't take a multivitamin with more than 100mcg of selenium.
We are finding that vitamin A is not as big a concern as earlier studies suggested. We tell our patients not to get more than 100% of the Daily Value for vitamin A from supplements, and to make sure that at least some of their vitamin A is in the form of beta carotene, which gives people some protection.So What Multivitamin Should I Buy?
"Multivitamins vary widely in quality," says Ted Cooperman of ConsumerLab.com, a website that analyzes dietary supplements. They conducted a study recently of popular multivitamins, results of which only subscribers ($33 a year) can see. I subscribe and just checked the website. From the list of approved multivitamins, I checked only those marketed for seniors or mature adults. And from those, I picked out three of the more popular. All three meet the CSPI recommendations on what a multivitamin should contain.
- Centrium Silver (11 cents)
- CVS Spectravite Senior (9 cents)
- Costco's Kirkland Signature Mature for Adults 50+ (3 cents)
- Men: Your multi should have no more than 200mg of calcium.
- Premenopausal Women: Your multi should have 18mg of iron.
The Center for Science in the Public Interest, founded in 1921, is an independent nonprofit consumer health group that advocates honest food labeling and advertising, and safer and more nutritious foods. It accepts no government or industry funding. It is supported by foundation grants and subscribers to The Nutrition Action Healthletter, which accepts no advertising.