How to get the nutrients you need: vitamin and mineral supplements help you feel your best and ward off illness. To reap their benefits, you need to take them the right way - Consumer guide: how to be an educated consumer - Cover Story

Natural Health, August, 2002 by Erin O'Donnell

TAKING VITAMIN AND MINERAL supplements may be one of the healthiest habits you can adopt. Mounting research suggests that supplements can help protect you against diseases like heart disease and cancer. "In addition to eating plenty of fruits and vegetables, I think it's smart to take vitamin and mineral supplements," says Jane Higdon, R.N., Ph.D., research associate at the Linus Pauling Institute in Corvallis, Wash. "Supplements are a good insurance policy" for times when your diet falls short, she says.

It's simpler (and cheaper) to take vitamins preventively than to treat disease when you're sick, but shopping for supplements is far from simple. The shelves in the supplement aisle are so crowded that it's hard to know where to begin.

To help you protect your health while saving time and money in the supplement aisle, we asked supplement researchers and nutritionally minded doctors hundreds of questions, like which supplements really prevent common diseases? What dose is most effective? And which forms work best? We sorted through their advice to create this guide to the most important vitamin and mineral supplements everyone should take. Most of the nutrients we describe can be found in a good multivitamin; we tell you how to choose a great multi, and let you know when you need to take other supplements, too.

Vitamin A and Beta Carotene

Why You Need Them: You need vitamin A (also known as retinol) to protect your eyesight as you age and to help your skin heal. Vitamin A comes from animal foods like liver, eggs, and milk, but your body also makes this vitamin from beta carotene, a plant chemical that gives orange produce its color. In addition to providing vitamin A, beta carotene, an antioxidant, neutralizes damaging free radicals. Studies show that people who eat five to nine daily servings of beta-carotene-rich produce have a lower risk of cancer.

Which Form Is Best: Choose a multivitamin supplement that supplies some vitamin A as retinol and some as beta carotene. (Check the label under vitamin A; most specify the percentage that's beta carotene. Choose a brand that offers at least 25 percent beta carotene.) Too much retinol may have serious side effects, says Higdon. A new study in the Journal of the American Medical Association found that women who took about 7,000 IU of retinol daily were at greater risk for hip fracture, and more than 10,000 IU daily can trigger miscarriages and birth defects.

And you don't want too much supplemental beta carotene, either, especially if you're a smoker or you're regularly exposed to cigarette smoke, says researcher Xiang-Dong Wang, M.D., Ph.D. A 1996 study found that smokers who took large doses of beta carotene had an increased risk of lung cancer. Based on recent studies he conducted on animals, Wang believes the problem arose because subjects took high doses of beta carotene alone, which appears to trigger pre-cancerous changes in smoke-exposed cells. Beta carotene probably needs to be combined with other plant chemicals found in fruits and vegetables to produce a beneficial effect, even if you're not a smoker, Wang says. For that reason, some practitioners recommend that everyone take "mixed carotene" supplements. But Wang recommends that you stick to the modest amount of beta carotene in a multivitamin and eat five to nine servings of carotene-rich foods like carrots, citrus fruits, and tomatoes every day.

Effective Dosage: Get vitamin A and beta carotene from a multivitamin that provides up to 5,000 IU of vitamin A. (Choose a brand that offers at least 25 percent as beta carotene.) Increase your protection against disease by eating five to nine servings of produce daily.

Vitamin B6

Why You Need It: Vitamin [B.sub.6] may reduce heart disease risk. Many studies over the last decade have confirmed that it works together with [B.sub.12] and folic acid to reduce blood levels of homocysteine, an amino acid that increases your chances of heart disease and cognitive decline as you age. Some practitioners recommend high doses of [B.sub.6] to help you cope with stress, carpal tunnel syndrome, and PMS, but those uses have been less studied. "Some people swear by those higher doses, but I just haven't found a lot of placebo-controlled research that supports them," Higdon says. And it's important to avoid very high doses of B6 (more than about 200 mg daily) because they can lead to numbness and nerve pain.

Which Form Is Best: Pyridoxine hydrochloride, a common, inexpensive form, appears to work fine, Higdon says.

Effective Dosage: Most of the experts we consulted recommend that you stick to about 2 mg of [B.sub.6] a day (the amount in many multivitamins). Doses of 50 to 100 mg a day (found in B-complex formulas) aren't harmful, Higdon says, but it's not clear that they're beneficial. Don't take more than 200 mg of [B.sub.6] daily.

Vitamin [B.sub.12]

Why You Need It: Like vitamin B6, vitamin [B.sub.12] helps reduce homocysteine, a substance in blood that increases heart disease risk. It may also influence your mood; studies show that depressed people are often deficient in the vitamin, and scientists believe [B.sub.12] helps your body produce SAMe, a compound that boosts levels of mood-lifting neurotransmitters.