What You Need to Know: Recent research shows Americans are meeting their dietary guidelines—but only one week out of the year. "If you find yourself skimping on fresh fruits, vegetables and whole grains, a multivitamin is a practical way to help fill that nutrient gap," says Blumberg. But that doesn't mean you can get away with eating junk for breakfast, lunch and dinner. "No supplement can hold a candle to a good diet," says Jason Theodosakis, M.D., Family Circle Health Advisory Board member and associate professor of family and community medicine at the University of Arizona College of Medicine.
If you're premenopausal, Kroger Complete Ultra Women's Health and Walgreens One Daily for Women multivitamins—each just six cents a day—are good choices, says Tod Cooperman, M.D., president of ConsumerLab.com, an independent firm that tests supplement safety. (For a free trial, go to ConsumerLab.com/FamilyCircle.) Nature Made Multi for Her 50+ is the best value for postmenopausal women, he says, because it costs 12 cents per day and contains enough calcium and vitamin D for bone health but no iron, which usually isn't necessary at this age.
Who Should Take It: Vegans, women on macrobiotic or 1,500-calorie-or-less diets and those who eat poorly. If your blood work is good, your doctor may instead recommend specific, individual vitamins and minerals to fill holes in your diet.
What to Watch Out For: Don't go over the Daily Recommended Intake (DRI). Switching to a multivitamin is usually a safe way to prevent this. "It's easy to consume too much of a nutrient when it's taken as a single vitamin," explains Blumberg. And megadosing—taking high doses of a single nutrient—can cause anything from nausea to kidney damage.
Get It Naturally: Eat at least one and a half cups of fresh fruit and two to two and a half cups of vegetables daily, and be sure at least 50% of the grains you choose are whole. Go to myplate.gov for recommendations on how to eat to meet nutritional guidelines.