Counseling Sheet

Agatha M. Thrash, M.D.
Preventive Medicine

Any supplementation of the diet should be done with great care, and is often associated with dangers, and unfortunately often with no improvement in the condition for which the supplements were given. Mega-vitamins given to 20 children with learning disabilities showed no improvement compared to a group treated by diet alone.

In one study of three adult males given large doses of nicotinic acid to treat high blood cholesterol, there was a loss of central vision. The nicotinic acid can cause retention of fluid and swelling in the retina, which could lead to a loss of vision. After the vitamin was discontinued some improvement of vision occurred.

Calcium supplements may interfere with the absorption of iron and zinc. Calcium supplements may also interfere with the function of vitamin K, which assists in the formation of blood clotting substances, and may lead to internal bleeding. There is some evidence that large doses of calcium may actually decrease bone strength as the ratio of calcium to other minerals essential for strong bones is altered in an unfavorable way. Some sensitive patients can have symptoms of arthritis by taking calcium supplements.