Supplementation with vitamin c and/or vitamin B6 in the prevention of depot-provera side effects in adolescents

Abstract

BACKGROUND: Depo-Provera induced menstrual irregularity is believed to be secondary to relative estrogen deficiency, and weight gain associated with this method is believed to be due to Depo-Provera steroid-like effect and to an altered tryptophan metabolism. We examined whether vitamin C, an important factor in uterine estrogen binding, and vitamin B6, a glucocorticoid antagonist and an important coenzyme in the tryptophan-serotonin pathway, might alleviate menstrual irregularities and weight gain associated with Depo-Provera.METHODS: Fifty five adolescent girls (age 16 ± 1 years, gyn age 4 ± 1 years, BMI 25.2 ± 0.9) who decided to initiate Depo-Provera (150 mg i.m. every 3 months) were randomly assigned to one of 4 groups: group 1-vitamin B6 50 mg plus placebo pill/day, group 2-vitamin C 500 mg plus placebo pill/day, group 3-vitamin B6 50 mg plus vitamin C 500 mg/day, group 4 (control)-2 placebo pills/day, for the duration of 6 months. Participants were assessed by their care providers every 3 months.RESULTS: Out of 55 enrolled, 33 girls (10-group, 1, 6-group 2, 10-group 3, 7-group 4) completed the study (13-D/C vitamins, 9-D/C Depo-Provera). Compared with the number of days of bleeding during the first interval (first 3 months) in the control group (7 ± 4 days), there was a significant increase in number of days of bleeding in group 2 (24 ± 6 days, p < 0.05) and in group 3 (22 ± 5 days, p < 0.05) and no difference in group 1 (13 ± 4 days, NS). Number of days of bleeding during the second interval (months 4-6) among groups 1 (15 ± 6 days), 2 (21 ± 10 days), and 3 (8 ± 4 days) did not statistically differ from days of bleeding in control group (16 ± 13 days). There were no significant BMI changes among groups 1-3 (−0.18 ± 0.20, −0.56 ± 0.16, −0.33 ± 0.32) compared with control (−0.16 ± 0.31) during the first interval as well as during the second interval (0.68 ± 0.37, −0.39 ± 0.21, 0.45 ± 0.32, compared with 0.25 ± 0.51). When data from all 33 participants were collapsed, there was a significant decrease in BMI (−0.29 ± 0.13, p < 0.05) during the first interval. About 48% at 3 months and 44% at 6 months were very or somewhat concerned about menstrual irregularity; 41% at 3 months and 18% at 6 months were very or somewhat concerned about weight changes. More than half (57%) at 3 months and 74% at 6 months reported less tampon/pad use, and 77% at 3 months and 78% at 6 months reported decreased menstrual cramps. Overall, 59% at 3 months and 70% at 6 months were very satisfied with Depo-Provera, 97% at 3 months and 96% at 6 months said that they would recommend Depo-Provera to a friend or a relative.CONCLUSION: This study does not support a role for vitamin C in the prevention of Depo-Provera induced menstrual irregularities or for vitamin B6 in the prevention of weight changes associated with Depo-Provera. Raising awareness and close follow-up may prevent weight gain among adolescent girls using Depo-Provera.