On Vitamin Megadoses : Experts Are Worried Over the Side-Effects of Some Supplements
The willingness of many Americans to self-prescribe specialized, high-dose vitamin and mineral supplements to prevent disease has some experts worried about dangerous side-effects.
“A lot of the advertising implies that certain supplements alone can prevent disease, and that more is better,” said Vera Fritz, a member of the National Council Against Health Fraud and with the Dairy Council of California.
“There is not only the danger of toxic reactions, there is the danger of upsetting the natural balance of nutrients in the body,” Fritz said. “These nutrients are more safely obtained from foods,” she said.
Problems With Calcium
Calcium in supplement form, for instance, can block the absorption of other bone-building minerals such as manganese and phosphorus, which ironically promotes osteoporosis. More than 70% of the calcium in the American diet comes from milk and dairy foods, and does not have the same effect from this source, Fritz said.
Other nutrients, such as Vitamin A and C, are being researched as potential cancer inhibitors. Vitamins A and C are abundant in broccoli, oranges and other fruits and vegetables. Manganese, found mostly in meats, is a key mineral in bone development. Healthy bones help prevent osteoporosis.
More than 40% of those using supplements take three or more specialized, high-potency pills daily, according to a study by the U.S. Food and Drug Administration.
Physical Damage
Advancing research on the effects of large doses shows definite physical damage in amounts as little as five to 10 times the Recommended Dietary Allowance (RDA), amounts that are easily available over-the-counter, according to Fritz.
Partially due to escalating costs of medical care, vitamin and mineral supplements are the fastest selling over-the-counter medication, surpassing even cold remedies, according to the New York research firm Frost and Sullivan. Sales will more than double between 1982 and 1990, the firm projects.
