Ever since your mom gave you your very first Flintstones chewable, you've considered taking a multi a daily necessity. But then a few months ago, a large-scale study conducted by the Fred Hutchinson Cancer Research Center in Seattle called that health no-brainer into question: Women who pop multivitamins don't reduce their risk of cancer or heart disease and don't live longer than those who go without, said researchers. Food, not pills, is where your nutrients should come from. So have you—and millions of other women—been wasting your money on something you don't even need?
"You might be—if your diet was perfect in every way," says Elizabeth Somer, R.D., the author of The Essential Guide to Vitamins and Minerals and a Shape advisory board member. But the truth is, none of us live in a perfect world, and our eating habits reflect that. As a result of dieting, skimping on fruits and vegetables (as 89 percent of women do), and being too busy to eat right at every meal, the majority of women don't meet the daily requirements for important nutrients, like calcium, magnesium, folic acid, and vitamin E, according to the U.S. Department of Agriculture. And over time, those deficiencies will take a toll on your well-being.
"That's why I recommend that every woman take a basic multivitamin," says Somer. "It's inexpensive and ensures you'll bridge any nutritional gaps." But even then, she says, just a multi may not be enough. Some healthy lifestyle choices—such as wearing sunscreen or running a marathon—can increase your need for certain vitamins and minerals even more. Read on to learn which common scenarios call for an extra dietary boost so you can lower your risk of illness, ramp up your energy, and shed a few pounds.