Effect of oral zinc supplementation on copper and haemoglobin levels in pregnant women

Abstract

In the present study, pregnant women in different trimesters of pregnancy were randomly allocated to untreated control group (Gp A; n = 58), and zinc treated group (Gp B; n = 104). Both groups were administered ferrous sulphate 60 mg, and folic acid 5 mg, twice daily throughout the period of study. Gp B subjects were also administered 45 mg elemental zinc, in a single daily post lunch dose. Maternal blood and urine samples collected in each trimester, and at the time of delivery, and blood taken from the umbilical cord were tested for Cu levels. Maternal Hb was also estimated. In Gp A, mean serum Cu increased significantly from 117.15 +/- 2.12 micrograms/dl in I trimester to 138.57 +/- 0.92 micrograms/dl in III trimester (P < 0.001). In Gp B, serum Cu declined significantly from 115.64 +/- 1.12 micrograms/dl in I trimester to 111.10 +/- 0.99 micrograms/dl in III trimester (P < 0.001). Urinary Cu declined significantly from 47.24 +/- 2.31 micrograms/24 hrs in I trimester to 37.43 +/- 2.06 micrograms/24 hrs in III trimester (P < 0.01). Zn treatment did not alter differentially the serum Cu levels in anaemic and normohaemic subjects. Gp B cord blood serum Cu was significantly lower as compared to respective controls, significance being proportional to duration of zinc administration. Hb levels increased significantly in all subjects. Increase in Hb in Gp B was significantly higher in comparison to that in Gp A (P < 0.05). Elemental zinc when administered to pregnant women in a dose of 20-45 mg/day, causes improvement in Hb level, without leading to hypocupremia.