Effect of ethynodiol diacetate and mestranol on serum folic acid and vitamin B12 levels and on tryptophan metabolism in baboons.

The effect of an oral contraceptive agent on serum folate and vitamin B12 levels and on some aspects of tryptophan metabolism in the baboon has been investigated. Folate levels were not affected by this treatment. Vitamin B12 levels were lowered during oral contraceptive treatment (P smaller than 0.1) and increased during a 30-day period of pyridoxine supplementation (P smaller than 0.01). Trends indicating deterioration of glucose tolerance and abnormal tryptophan metabolism were also observed. Definite conclusions concerning the effect of oral contraceptive agents on nutritive parameters could not be made. This is in keeping with the vast volume of literature published on the effects of oral contraceptive agents in humans and other species. It is concluded that perhaps, due to the biologically variable responses to oral contraceptive agents by individuals of any species, studies of serum levels of vitamins and other superficial biochemical parameters. Further, we conclude that the baboon could be a useful model for the study of endocrine influences on nutritive parameters, first because endocrine parameters resemble those of humans and second, because experimental protocols can be rigidly adhered to.