Effect of oral contraceptive use and zinc supplementation on zinc, iron and copper biochemical indices in young women

SummaryBackground & aimsOral contraceptives (OC) generally increase serum copper and iron and decrease serum zinc. In OC users, zinc supplementation could benefit the balance among these minerals. Our aim was to evaluate the effect of OC use on several zinc, iron and copper biochemical indices, and on their response to zinc supplementation.MethodsSerum and urinary zinc, erythrocyte zinc and metallothionein, plasma alkaline phosphatase, serum iron, total iron-binding capacity (TIBC), transferrin saturation, serum ferritin, serum copper, plasma ceruloplasmin, erythrocyte copper and Cu–Zn superoxide dismutase (SOD), and serum Fe/Zn and Cu/Zn and erythrocyte Cu/Zn were compared between women users (+OC, n = 19) and non-users (−OC, n = 17) of OC, before and after 8 wks of zinc supplementation (22 mg/d).ResultsOC+ presented lower serum and urinary zinc (P < 0.005) but higher serum iron, TIBC, ferritin (P ≤ 0.005), copper and ceruloplasmin (P < 0.001), SOD (P < 0.05), and serum mineral molar ratios (P < 0.0001). Zinc supplementation did not affect iron indices but it increased serum and urinary zinc (P < 0.05) only in −OC. In +OC, zinc supplementation decreased erythrocyte zinc (P = 0.05) but increased serum copper, ceruloplasmin, and serum Cu/Zn ratio (P < 0.05).ConclusionsOC use influenced zinc, iron and copper homeostasis. Zinc supplementation further altered copper utilization in OC users, possibly favoring oxidative stress.