Effect of oral contraceptives agents on thiamin, riboflavin, and pantothenic acid status in young women

Abstract

Thiamin, riboflavin, and pantothenic acid status were determined in 13 young women, ages 19-25, at the beginning and end of a 12-day confined study. 9 women were using (+OCA) oral contraceptives and the other 4 were not (-OCA). The subjects entered the metabolic unit during the 1st week of their menstrual cycle and were fed a constant formula diet containing 2.0 mg thiamin, 3.0 mg riboflavin, and 10 mg pantothenic acid. Prestudy intakes, estimated from 3-day dietary records, were about 1/2 of the thiamin, riboflavin, and pantothenic acid levels fed in the study, and were similar in both groups. Use of OCs did not appear to influence the activity of erythrocyte transketolase or erythrocyte glutahione reductase or the response of these enzymes to in vitro stimulation by their cofactors. The enzymes were responsive to the levels of thiamin and riboflavin fed during the study, however. In the +OCA group, erythrocyte transketolase and erythrocyte glutahione reductase stimulation by their cofactors was significantly decreased by day 12. At the beginning of the study, blood and urine pantothenic acid levels were significantly lower in the +OCA group than the -OCA group. These differences were no longer evident by the end of the study. The data show that when dietary intakes and times of sampling in the menstrual cycle are controlled, OCs do not cause significant changes in the biochemical parameters of thiamin, riboflavin, and pantothenic acid status.