Evaluation of serum Vitamin B₁₂ levels in hormonal contraceptive users in some hospitals in Kano Metropolis

Abstract

Aim: The aim of the study was to compare the levels of Vitamin B12in hormonal contraceptive users and women not on hormonal contraceptives in Kano.

Methods: A total of 90 participants were recruited for the study; 60 were on hormonal contraceptive (HCP) users and served as the study subjects while 30 were apparently healthy non hormonal contraceptive users recruited as control subjects. Serum VitaminB12levels were evaluated for both groups and the mean levels were compared.

Results: Among the 60 HCP users that were enrolled in this study, 29 use implants (48.3%), 14 (23.3%) used injectables;11 (18.3%) use oral pills and 6 (10.0%) participants used intrauterine contraceptive devices. Serum vitamin B12 levels of the two groups were determined using human B12 specific ELISA kit. The mean ± standard deviation of vitamin B12 levels in hormonal contraceptive users was 163.33±53.128 pg/ml while that of non-HCP users was 381.33±198.542 pg/ml. Statistical analysis for B12 levels indicated a statistically significant decrease in oral contraceptive users with a p-value of <0.001. The study also found statistically significant negative correlation (r<1) between duration of hormonal contraceptive use and serum vitamin B12 levels of HCPs users with r-value of -0.031 and p-value of 0.020.

Conclusion: The present study observed a significant association between hormonal contraceptive use and serum vitamin B12 level. Significantly lower serum vitamin B12 concentrations were observed in HCP users. Therefore, Vitamin B12 supplementation or different contraceptive methods should be considered in women with pre-existing B12deficiency or restrictive dietary habits as the deficiency may be worsened by hormonal contraceptive use.

Keywords: Contraception; Combined oral contraceptives; Vitamin B12; Vitamin B12 deficiency