Effect of oral contraceptive agents on nutrients: II. Vitamins

Abstract

Clinical, biochemical and nutritional data were collected from a large population of women using oral contraceptive agents. Higher incidence of abnormal clinical signs related to malnutrition were observed in the lower (B) as compared to the higher (A) socioeconomic groups, and also in the nonsupplemented groups as compared to the supplemented groups in the B subjects. As a rule the intake of oral contraceptive agent subjects of vitamin A, C, B6 and folic acid did not differ from that of the controls As expected, subjects from the supplemented groups had higher intake of vitamin A, C, B6, thiamin, riboflavin and folic acid, and A groups had higher intake of vitamin C, B6, riboflavin and folic acid. Increased plasma vitamin A and decreased carotene levels were observed in oral contraceptive agent users. In general oral contraceptive agents had little or no effect on plasma ascorbic acid. Urinary excretion of both thiamin and riboflavin in subjects using oral contraceptive agents were lower in A groups. Erythrocyte folate and plasma pyridoxal phosphate was decreased in A groups due to oral contraceptive agents. Subjects who took supplements had higher levels of plasma vitamin A, ascorbic acid and folate. But urinary thiamin and riboflavin were higher only in group A subjects who took supplements.

PIP: 18-45 year old women were tested to determine if the use of oral contraceptive agents (OCAs) affects the metabolism of vitamins. 4 different hormonal conditions and 2 socioeconomic levels in 8 groups were considered. Some of each socioeconomic level had taken Norinyl (1 mg norethisterone and 50 mcg mestranol) for 3 months or more. Others had used Ovral (.5 mg norgestrel and 5 mcg ethinyl estradiol) for equal periods. There were some in each group who had resumed use of OCAs during lactation within 5 weeks after pregnancy. Vitamins and mineral supplements were given to groups in each socioeconomic classification. They had a higher intake of Vitamins-A, C, thiamin, riboflavin, and folic acid. Incidence of clinical sings of malnutrition, such as dry skin, easily pluckable hair, angular lesions of the mouth, dental caries, bleeding gums, glossitis, and scaling of the skin, were significantly more frequently observed in the lower socioeconomic groups, and especially in nonsupplemented groups of women taking OCAs than in others. OCA administration increased plasma Vitamin-A levels but no socioeconomic effect was found. Plasma carotene levels were decreased by OCA therapy, but less so in the higher socioeconomic subjects. Plasma ascorbate was not affected by OCA use. Urinary excretion of thiamin annd riboflavin was decreased in subjects using OCAs. Erythrocyte folate and plasma pyridoxal phosphate (PLP) were also decreased. Results show a definite lowering effect of OCAs on red cell folate in subjects in the upper socioeconomic levels. There may also be a depletion of body stores of folic acid. It has been suggested that women who become pregnant soon after discontinuing OCA therapy have a high chance of developing folic acid deficiency during pregnancy. The lower socioeconomic group may be marginally deficient in folic acid. Similar results were obtained with thiamin and riboflavin. Changes due to OCA use with respect to thiamin, riboflavin, folate, and PLP were seen mainly in subjects in the upper lower socioeconomic groups may have prevented detection of smaller similar alterations due to OCA use.