What should you look for?

The best multivitamin for women “has about 100% of the Daily Value [DV] of most of the essential vitamins and minerals,” advises Jeffrey Blumberg, PhD, professor of nutrition at Tufts University. But don’t expect it to have 100% of the DV of calcium, because that amount is too large to fit into a multi. And be sure to note the amount of vitamin A. “Taking more than 100% of the DV may cause bone fractures in postmenopausal women and is linked to birth defects,” says Helen Delichatsios, MD, instructor of nutrition at Harvard Medical School. “To play it safe, select a multi that has part or all of its vitamin A as safer beta-carotene.”

[sidebar]Do you need a special formula?

A basic multi is all you need unless you fall into a group with special vitamin/mineral requirements. Women who are or are trying to become pregnant should choose a prenatal supplement because it has higher-than-normal amounts of folic acid, iron, zinc, and calcium—all critical to healthy births. Men and women over 50 benefit from a “seniors” formula that has extra vitamin D, vitamin B12, and calcium. But most older people don’t have to watch the iron content of their multi as carefully as you might think. “The evidence that supplemental iron might be a heart disease risk factor in men and postmenopausal women is mixed,” says JoAnn Manson, MD, professor of medicine at Harvard Medical School and chief of preventive medicine at Brigham and Women’s Hospital in Boston. “The small amount of iron [18 mg per day] from a standard multi is probably safe for most people.” However, if you have hemochromatosis (iron overload), select an iron-free preparation.

Should you choose all-natural, sugar-free, starch-free, or slow-release products?

Many people prefer using products with all-natural ingredients or no sugar or starch. It’s really a personal decision. But those terms don’t mean the product is better absorbed. As for slow-release multis, Dr. Blumberg says there’s not enough evidence that they offer any advantage to counter the extra cost.

Is there any benefit from added lycopene and lutein?

Unfortunately, the benefit is only minimal. Lycopene, lutein, and other carotenoids may help to lower the risk of chronic diseases such as cancer. However, the amounts that are found in most multis are quite low, says Dr. Blumberg. Although every little bit helps, you still need to eat lots of fruits and veggies to get optimal intakes of these important compounds.

What about the other extras such as enzymes, green algae, EGCG, amino acids, or herbs such as ginkgo?

“Stick with the basics; your multi doesn’t need bells and whistles,” says James Dillard, MD, professor of medicine at Columbia University. Why? There are decades of research on vitamins and minerals, but not much data on these extras. As for herbs, it may seem convenient and economical to get herbs in your multi, but Dr. Blumberg says it’s not a good idea. “Herbs are not nutrients; they are taken for very specific effects in the body.”  His advice: “If you want to take an herb such as ginkgo, then buy a product that contains only that and in the proper dosage.” More from Prevention: 100 Best Supplements For Women