What Vitamins Do You Really Need?

Everyone's telling you something different when it comes to which supplements you should pop - and which ones you should stop. Here, advice you can trust. By Kim Tranell, REDBOOK.

If you buy into health headlines, your medicine cabinet may be full of bottles bought based on news of disease-fighting, symptom-easing superpowers…and then abandoned when conflicting reports emerge. "Supplements can be helpful to fill in a gap in your diet," says Carol Haggans, M.S., R.D., a scientific consultant with the National Institute of Health's Office of Dietary Supplements. "But if you think that taking a vitamin or mineral is going to prevent certain diseases like cancer or heart disease, there's just no good evidence that's true." To complicate matters further, some recent research has found that supplementing may do more harm than good. To sort through the hype and the horror stories, start with this quick primer on what experts say you do and don't need.

Multivitamin

The verdict: Yes

Is your multi a magic cure-all pill? Probably not, say experts. But it can certainly act as an insurance policy against any gaps in your diet - especially for women of childbearing age. "It's just like how you put on your seatbelt when you get in the car," says Tieraona Low Dog, M.D. author of Life is Your Best Medicine and an expert in dietary supplements. "You don't do it because you know you'll get in an accident - but just in case." The makeup of multis varies wildly, so always check the back of the bottle or box to ensure you're getting 70 to 100 percent of most vitamins and minerals - no more, no less - with the exception of calcium, which is usually present in lower amounts. (The reason: Calcium is bulky so it's hard to fit a lot into a multi.)

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Folic Acid
The verdict: Yes

Foods are widely fortified with folic acid these days, but some women still don't get enough of the nutrient, which has been shown to prevent neural tube defects in unborn babies. So if you're looking to get pregnant (or even if you simply could), be sure your multivitamin meets the RDA (Recommended Daily Allowance) of 400 mcgs. "The truth is, many pregnancies are unplanned, and neural tube defects happen early on," says Haggans. "Taking it once you learn you're pregnant is too late."


Calcium
The verdict: Maybe

You know calcium is crucial for building bone mass and preventing osteoporosis, but before you start popping Tums like candy, give your daily diet a mental check. That RDA (1000 mg for women ages 19-50) works out to about four small servings (think: a cup of milk or yogurt or a slice of cheese) - and even a little less than that if you're already taking a multi. "Many women don't realize it's possible to hit your recommended daily allowance with food," says Dr. Low Dog. If you're lactose intolerant or suspect your diet is lacking, talk to your doc about possibly taking 500 mg twice a day. (Larger doses are too hard for your body to absorb all at once.) However, be careful not to overdo it - research shows that taking too much might cause kidney stones in some women.

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Vitamin D
The verdict: Maybe

Most of us don't get enough of the "sunshine vitamin," which can you've been told might build bones, strengthen immunity, and prevent diseases like diabetes and cancer. But heed the hype: Darisuh Mozaffarian, M.D., an associate professor of medicine at Harvard, cautions that the evidence for these benefits is still weak - and not enough is known about the potential long-term effects of amping up your vitamin D intake with supplements. And if you suspect you might be deficient (your risk rises the darker your skin, the less time you spend in the sun, and the fewer servings of fatty fish and milk you get), ask your doc to do a simple blood test to check your levels before you decide to supplement on top of your multi.


Iron
The verdict: Maybe

Yes, women need iron. And yes, many women don't always hit their RDA. But aside from those who are expecting (your iron needs almost double during pregnancy) and those with heavy periods, most docs say there's typically no need to take extra - unless you're anemic. "But don't self-diagnose," says Dr. Mozaffarian. "It's easy enough to ask your doctor for a blood test to check your levels and get advice on supplementing." One word of warning, though - iron pills are notorious for, er, clogging your pipes. So if you experience constipation, Dr. Low Dog suggests seeking out a food-based form, which could be easier on your digestive system.


Fish oil

The verdict: Maybe

The jury is still out on how much taking fish oil (a source of omega-3 fatty acids) will help your heart or boost your mood. "It's spotty," says Haggans. "There's pretty good evidence that it can lower your triglycerides, but much of the other research is not as clear right now." One thing the experts all agree on, though: Pregnant and breastfeeding women need 300 mg of fish oil a day to ensure they're getting enough DHA, the omega-3 fatty acid essential for a baby's brain and eye development. Try to get it from food (8-12 ounces of seafood a week will do it), but if you're afraid you can't hit that number, talk to your doctor about supplementing.

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Vitamin B12
The verdict: Maybe

Remember when Hollywood got on the B12 bandwagon? Well, the vitamin is still being marketed to give you an energy boost - but experts say that's not necessarily a legit claim. "If you have a B12 deficiency, which makes you fatigued, correcting that deficiency will bring your energy up," says Haggans. "But if you aren't, B12 isn't going to help at all." That said, the vitamin is found mostly in meat and dairy products, so vegetarians and vegans might want to talk to their doctors about supplementing.


Probiotics
The verdict: No

Do these "good bacteria" really beef up your immune system, protecting against stomach bugs and the common cold? File under: No evidence they'll hurt you, no evidence they'll help you - yet. "They appear to be relatively safe, if you want to try them," says Haggans. "But more research is definitely needed before we fully understand what health benefits they might have."


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