To B-3 or not to B-3

The straight dope on vitamin supplements

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When people learn I’m a medical writer, the question they most frequently ask is: “Do you take vitamins?” I do—two pills a day, a multivitamin/mineral “insurance formula,” and an antioxidant booster containing vitamins A (in the form of beta-carotene), C, and E, as well as the mineral selenium. Quite often I get incredulous looks or even an argument along the line that I (along with the almost 50 percent of Americans who take vitamins) have been duped by the $6.4 billion-a-year industry’s hype and am wasting my money. A balanced diet, critics say, should supply all the nutrients I need.

Supplement aficionados, on the other hand, can’t believe I take only two pills a day. They often take a half-dozen with each meal, spending up to $40 a month. (I spend maybe $8.)

Both arguments have flaws. It is prudent to take supplements, but don’t spend more than $10 a month. Here’s why:

Food first. Fewer than 30 percent of Americans eat the recommended five servings of fruits and vegetables per day. And that’s just the minimum. For optimal health, you need to eat eight or nine servings a day—in other words, you have to have a near vegetarian diet, meaning there’s not a whole lot of room left for meat (let alone junk food).

If you’re eating a nutrient-poor diet, supplements won’t make up the difference. Take vitamins only as an addition to maintaining a healthy, mostly vegetarian diet—that’s what “supplement” means. Consider vitamin A. Multivitamins usually contain beta-carotene, the most abundant of the vitamin A family of nutrients, the carotenoids. But beta-carotene is only one of an estimated 600 carotenoids, all of which are important for good health. Lycopene, for example, is not usually found in supplements. A 1995 Harvard study found that it helps protect against prostate cancer. (For a good source of lycopene, eat tomatoes and tomato products.)

But recent research also shows just how beneficial some supplements can be. Vitamin B-6 can help relieve morning sickness; vitamin C helps prevent cataracts; vitamin D can reduce the risk of osteoporosis; vitamin E can safeguard against heart attacks; selenium could be a strong cancer-preventing antioxidant; and general supplement use by the elderly can help boost their immune systems. If you know how to choose them, supplements are the cheapest health insurance you can buy.

Cheap, however, is the key word. Forget brand names. The industry’s dirty little secret is that most vitamins are identical. Only five or six wholesalers supply raw ingredients to just three major companies that create the pills, packaging the same vitamins under hundreds of different labels. When you buy expensive vitamins, you’re simply underwriting the marketer’s fancy packaging and advertising. Store brands, for example, are often identical to national brands, but half the price.

As for what and how much to take, here’s a distillation of what the experts advise:

  • The RDAs are too low. The myth is that the National Academy of Sciences’ “recommended dietary allowances” (RDAs) are the gold standard of nutrition—get 100 percent and you’re covered. In fact, the RDAs are highly controversial, and many scientists insist that current RDAs are too low. Take vitamin C, for example. Its RDA for adults is 60 mg a day—enough to prevent scurvy, but that’s about it. A 1996 study pegged the optimal daily dose closer to 200 mg. If you eat five servings of high-C foods (citrus fruits, broccoli, cabbage, red and green peppers) a day, you can easily consume more than 300 mg; otherwise, look to supplements for larger doses.


    Iron is the only truly hazardous supplement: Only a few adult pills can kill a child. As for other vitamins, they’re safe unless you take them in megadoses—at hundreds of times the RDA. Watch for the following:

    VITAMIN A Doses above 100,000 international units (I.U.) can cause dizziness, blurred vision, and vomiting. If you’re pregnant, too much or too little can cause birth defects.
    VITAMIN B-3 Doses over 2 grams may cause liver damage.
    VITAMIN C High doses may cause diarrhea. Individual thresholds vary.
    VITAMIN D Daily doses above 1,000 I.U. may cause nausea, headache, fatigue, diarrhea, loss of appetite, and possibly irreversible kidney and heart problems.
    MAGNESIUM High doses (3,000 mg) have a laxative effect. In fact, magnesium is the active ingredient of the over-the-counter laxative milk of magnesia.
    ZINC High doses (1,000 mg or more) cause nausea and vomiting.
  • Which brings us to the alleged hazards of high dosages. Guess how many adults were killed by supplements in 1995-96 (the two most recent statistically complete years): just one, according to the American Association of Poison Control Centers. Supplementing your vitamin intake up to three times the RDA is generally safe. (See table at right for a detailed list.)

  • Start with a multivitamin/mineral “insurance formula.” Insurance formulas, a.k.a. “multis,” contain some of every major vitamin and mineral. Read labels. Look for brands that deliver at least 100 percent of the RDA in one or two pills. Insurance formulas are convenient, economical, and, compared with single-nutrient supplements, better for you. Vitamins and minerals work synergistically. Vitamin E works best with vitamin C; calcium works best with vitamin D. Nature packages nutrients together in food, and it’s best to take supplements that way, too.

  • Take your vitamin A as beta-carotene. Large doses of vitamin A can cause problems (see table at right). Beta-carotene is a form of vitamin A that’s nontoxic even at high doses.

  • Consider supplementing your insurance formula. For example, most don’t have enough calcium. A good, cheap source is Tums 500 chewable tablets. Other conditions that might require supplementation include pregnancy, menopause, competitive athletics, and many acute and chronic illnesses. Consult a clinical nutritionist or a naturopathic physician.

  • “Natural” vitamins are usually no better than laboratory creations, with a few exceptions. Chemically, there’s no difference between the vitamin C in an orange and the vitamin C in a test tube. Frequently, packagers mix a tiny amount of a natural vitamin with a large amount of a synthetic variety, call it “natural,” and jack up the price. Labels can be misleading. If you spring for a brand that claims to deliver 100 percent natural whatever, you’re usually wasting your money. The exceptions:

    Take only natural vitamin E (d-alpha-tocopherol). The body’s cells don’t recognize the synthetic vitamin (dl-alpha-tocopherol) as vitamin E or process it appropriately. If the label says “with” d-alpha, you may get only a tiny amount of the natural vitamin mixed with lots of the synthetic. Be sure to get the pure d-alpha form. The “organic” forms of selenium and chromium also are absorbed better than the synthetics. Look for selenium-rich yeast or l-selenomethionine and chromium-rich yeast.

    And with folic acid, avoid the natural form and go with the synthetic. Synthetic folic acid is easier to absorb.

  • Don’t pay extra for “chelated” minerals, which have been combined with proteins. Proponents claim that the process promotes absorption, and it does, but minimally. A better idea is to take your supplements with meals, which also improves absorbability.

  • Don’t spend more than $10 a month on expensive brand-name vitamins—instead, splurge on the finest fruits and vegetables.
  • Fact:

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