Vitamin metabolism and the effects of multivitamin supplementation in oral contraceptive users
Amatayakul, K.; Uttaravichai, C.; Singkamani, R.; Ruckphaopunt, S.
Contraception 30(2): 179-196
1984
ISSN/ISBN: 0010-7824 PMID: 6437739 DOI: 10.1016/0010-7824(84)90102-1Document Number: 406039
The effect of combined oral contraceptives containing 158 .mu.g of levonorgestrel and 38 .mu.g of ethynyl estradiol on vitamin B-1, B-2, B-6, B-12, folates, vitamin A, carotenoids, vitamin E and tryptophan load test was studied in a group of 34 healthy non-lacting women. This was compared to an identical study conducted in another group of 19 subjects who used IUD for contraception, and also in 2 other groups of subjects who were given an additional multivitamin preparation on a daily basis (33 subjects) and on the days when OC was not taken (29 subjects). Assessments were made prior to, and during the 3rd wk of the 4th, 7th and the 13th cycles of OC treatment. Urinary xanthurenic acid excretion (XA), plasma vitamin A and the folate content of the sera and red blood cells were significantly increased by OC treatment, although this excessive XA excretion was adequately corrected with 18 mg of daily vitamin B-6 supplementation. The metabolism of the rest of the vitamins was not significantly altered by OC usage. A routine use of multivitamin supplement may not be necessary.