Drugs and vitamin deficiency.

During the past 10 to 20 years it has become increasingly clear that a certain number of drugs may lead to increased vitamin requirements. However, it is unusual for symptomatic avitaminosis to develop, and then only when circumstances are present which in themselves increase the risk of vitamin deficiency. Therapeutic doses of drugs will interfere with the vitamin status only to a restricted degree, provided they are administered for brief periods and to patients receiving a normal supply of vitamins. Most cases of vitamin deficiency have in fact been described in connection with drugs usually taken for a longer period of time by patients who were already in negative vitamin balance as a result of disease or marginal supply of the necessary vitamins. This review describes some of the more important articles covering this topic.