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.
1. You're Trying to Slim Down
You Need CALCIUM
You skipped dessert and hit the gym all summer long—and still haven't dropped those last 5 pounds. What gives? Chances are you're one of the 75 percent of women who fall short of the recommended 1,000 milligrams (mg) of calcium daily. A new study in the British Journal of Nutrition suggests that not getting enough of this mineral may make it harder to take the weight off: When researchers put overweight, calcium-deficient women on a low-calorie diet, they found that those who took a 1,200-mg calcium supplement daily shed 11 more pounds in four months than those who continued to get less than 800 mg a day. Researchers say calcium may regulate the secretion of leptin, a hormone that controls appetite.
Daily dose At least 1,200 mg a day in three doses of 500 mg or less. The body can absorb only that amount at once, says Somer; most multis contain between 100 and 450 mg. Avoid taking them with caffeine and wheat bran, both of which block absorption.
Food sources 1 cup calcium-fortified orange juice (350 mg), 3 ounces sardines (325 mg), 1 cup cooked soybeans (195 mg), 1 cup cottage cheese (187 mg).
2. You're on the Pill
You need VITAMIN B6
Feeling tired and sluggish all the time? Your birth control may be to blame. In a study from Tufts University, 75 percent of oral contraceptive takers who weren't taking a multivitamin had low levels of energy-boosting vitamin B6. "It may be because the vitamin is used to metabolize estrogen, the main component in many birth control pills," says lead researcher Martha Morris, Ph.D. Vitamin B6 helps convert food into energy and maintain nerve function, so shortchanging yourself can lead to fatigue, irritability, and even depression.
Daily dose 2 mg, which you can get from most multivitamins. You can also switch from a regular vitamin to a prenatal one. "Each prenatal pill usually contains 2.6 milligrams of B6 or more," says Morris. "But beware of megadoses, because regularly getting 100 milligrams or more of the vitamin can lead to nerve damage."
Food sources 1 baked potato (0.5 mg), 1 banana (0.4 mg), 1 cup red pepper slices (0.3 mg).
3. You're a Vegetarian
You need VITAMIN B12 AND IRON
About 26 percent of vegetarians and 52 percent of vegans (people who avoid dairy and eggs in addition to meat) are deficient in vitamin B12, according to a recent study from Saarland University Hospital in Germany. That's because animalderived products are the only natural sources of the nutrient, which helps maintain healthy nerves and red blood cells. "Skimp on B12 regularly, and you'll put yourself at risk for nerve damage, memory problems, and heart disease," says Somer.
Vegetarians may also be putting their health at risk if they don't watch their iron intake. The iron in meat is absorbed more efficiently than the kind in plant-based sources, like beans and tofu; as a result, vegetarians need 33 mg of the mineral, while meat eaters require only 18 mg, according to the Institute of Medicine. Because iron helps ferry oxygen throughout the body, not getting enough can lead to fatigue and anemia. Consult with your doctor before taking an iron supplement, though—she'll check your blood level and let you know if you need one (excess iron can damage organs, like your liver and heart).
Daily dose 2.4 mcg of vitamin B12 and 33 mg of iron (most multivitamins provide 6 mcg of B12 and 18 mg of iron). Avoid taking your pill with coffee or tea, which can block the absorption of iron.
Food sources 1 cup lentils (7 mg iron), 1 cup fortified whole-grain cereal (6 mcg B12), 1 veggie burger (2 mg iron).
4. You Slather on Sunblock
You need VITAMIN D
Good for you—by applying an SPF year-round, you're drastically lowering your chances of developing skin cancer. But unprotected sun exposure is the top source of vitamin D (about 15 minutes fulfills your daily quota), a nutrient that 75 percent of adults are deficient in. "Sunscreens block up to 99 percent of the skin's production of vitamin D," says Adit Ginde, M.D., an assistant professor of surgery at the University of Colorado Denver School of Medicine. A crucial nutrient for the body, vitamin D protects against a long list of conditions, including breast and colon cancers, osteoporosis, high blood pressure, and diabetes.
Daily dose 1,000 international units (IU) of vitamin D3, which is more potent than vitamin D2. Most multivitamins provide 400 IU.
Food sources 3.5-ounce salmon fillet (360 IU), 1 cup nonfat fortified milk (98 IU), 1 egg (20 IU).
5. You're training for a race
You need CALCIUM AND VITAMIN D
Hitting the running trails can shore up your bones, but tacking on extra miles may have the opposite effect. "I you increase activity quickly, your bones may not have the support or strength to resist the repetitive pressure, which puts you at a higher risk for stress fractures," says Diane Cullen, Ph.D., a professor of biomedical sciences at Creighton University.
But upping your intake of calcium and vitamin D (which boosts calcium absorption) can offer protection: Cullen found that female Navy recruits who took a supplement with 2,000 mg of calcium and 800 IU of vitamin D daily during an eight-week training course were 20 percent less likely to suffer a stress fracture than those who didn't. "Doubling the daily dose of calcium helps repair bone that may get harmed in training," says Cullen.
Daily dose Aim for 2,000 mg of calcium and 800 IU of vitamin D before the race.
Food sources 3/4 cup fortified whole-grain cereal (1,000 mg calcium and 40 IU vitamin D), 1 cup nonfat milk (302 mg calcium and 98 IU vitamin D).
6. You're Pregnant
You need OMEGA-3 FATTY ACIDS
Most moms-to-be know to load up on folate and calcium. Now there's another nutrient to add to the arsenal: omega-3s. "This healthy fat [particularly DHA, one of the types found in fish] helps the baby's brain neurons and vision receptors develop," says Somer. In fact, a study in the Journal of Pediatrics found that moms who consumed more DHA during pregnancy had children who scored higher on vision and motor skill tests than those who got less.
Unfortunately, the average woman takes in about 84 mg of omega-3s a day—less than a third of the amount that's recommended during pregnancy. Many expectant mothers shun seafood because they can't stand the fishy smell or taste or are nervous about its mercury content. If that's the case, a supplement is your best bet. To find a contaminant-free brand, search the International Fish Oil Standards' database at ifosprogram.com.
Daily dose 300 mg of DHA. If you can't tolerate fish oil supplements, try one made with an algae-based ingredient, such as Life's DHA (lifesdha.com).
Food sources Fortified foods, like 1 DHA-fortified egg (135 mg), or 2 servings of fatty fish per week.