Effect of oral contraceptive use on ascorbic acid and vitamin A in lactation.

A large prospective study is being undertaken on the effects of OCs (oral contraceptives) on vitamins and trace elements in the plasma and milk of lactating women. Results presented here are of progestagen-only OC effects on ascorbic acid and vitamin A in the plasma and milk of 5 volunteers. 3 of the women took 350 mcg norethisterone and the other 2 took 30 mcg levonorgestrel daily. Their pretherapy age, height, weight, dietary data, and breast feeding history were recorded. Blood samples and fasting milk samples were taken for 19 weeks and the results graphed and analyzed. Findings of the study in general suggest that progestagen-only OCs have little or not effect on milk or plasma levels of vitamin A and ascorbic acid. Actual results show little change in plasma ascorbic acid but a slight, nonsignificant, decrease in milk ascorbic acid levels. Supplementation with ascorbic acid pills promptly increased milk ascorbic acid levels. Milk fluctuations were greater for vitamin A than for ascorbic acid. There was little weekly variation in plasma vitamin A. Changes in vitamin A and ascorbic acid levels were also observed in 9 breast feeding women who were not taking OCs. The lack of effect was expected since most changes in vitamin status have been attributed to estrogen content of OCs.