The Vitamin Myth

While some vitamin supplements can boost your health, others may actually harm.

By Neena Samuel from Reader's Digest | November 2007

Everyone needs vitamins and minerals, which are crucial for good health and long life. What we don’t need are megadoses of these essential nutrients in pill form. The greatest health benefits come when we get our vitamins from a balanced diet — but only 3 percent of us eat well enough for that. So unless your doctor has advised you to take a supplement for a specific medical reason, a daily multivitamin is all most healthy individuals need. Read labels to see how much you’re getting of each nutrient, and ask your doctor before starting any vitamin regimen, especially if you already take prescription drugs. Based on the latest studies, here are ten you can skip:

Vitamin A: Excess amounts accumulate and can be toxic. Too much A can blur vision, cause headaches and vomiting, and also lead to liver, bone and central nervous system problems, among others.

RDA*: Men – 900 mcg. Women – 700 mcg. One 7-inch carrot has 600 mcg. Other food sources: fortified cereals, dark leafy greens, fruits, sweet potatoes.

Beta Carotene: The body converts this into vitamin A. Supplementation is not recommended for the general public and should be avoided especially by smokers, who have a greater risk of lung cancer with regular use. Another recent study found that high levels of beta carotene in the blood were linked to three times the risk of aggressive prostate cancer.

RDA: None established. You can get what you need from dark green and orange fruits and veggies.

Vitamin C: There’s no conclusive evidence that it prevents colds, heart disease, cataracts or cancer.

RDA: Men – 90 mg. Women – 75 mg. Smokers need an extra 35 mg. A glass of OJ will give you almost all you need.

Vitamin E: Large doses can thin the blood and may increase the risk of hemorrhagic stroke in those with uncontrolled blood pressure. Has not been proven to protect the heart or prevent cancer.

RDA: 15 mg. An ounce of dry-roasted almonds will provide almost half your daily needs.

Selenium: Most Americans get enough of this trace mineral in their diet. One new study suggests that adding more via a pill may increase the risk of developing type 2 diabetes.

RDA: 55 mcg. Grab a tuna sandwich or a handful of Brazil nuts instead.

*RDA is for general adult population. Some groups, such as pregnant or breast-feeding women, need more.