Effect of Vitamin C on Glutathione Peroxidase Activities in Pregnant Nigerian Women - An Ilorin Study

Abstract

Glutathione peroxidase is one of the most important antioxidant enzymes in humans. We studied the relationship between serum glutathione peroxidase activity and vitamin C ingestion during normal pregnancy in women attending antenatal clinic in the University of Ilorin Teaching Hospital, Ilorin. Glutathione peroxidase activity was determined at entry in early second trimester and six weeks later within the same trimester involving sixty women. Twenty non-pregnant women served as controls, while forty pregnant women were divided into two groups of twenty each. One group of the pregnant women did not receive vitamin C, while the other group received 100mg of vitamin C. All the pregnant women were on their routine antenatal drugs of folic acid and ferrous sulphate. During pregnancy, glutathione peroxidase activity reduced significantly between entry and six weeks later in normal pregnancy, from 240.25±14.41 to 231.05±8.63 (p<0.05). The reduction of glutathione peroxidase activity in pregnant women that took vitamin C was not statistically significant, after six weeks of ingestion. Glutathione peroxidase activity fell from 241.65±12.77 to 239.80±13.83 (p>0.05). Statistically significant associations (all positive) were observed between glutathione peroxidase activity in normal non-pregnant women and all the pregnant groups (p<0.05). In conclusion, we demonstrated that normal pregnancy is associated with reduced glutathione peroxidase activity, and that ingestion of vitamin C reduced the deleterious effects of pregnancy on the activity of glutathione peroxidase.

Keywords: Pregnancy, Glutathione Peroxidase, Vitamin C, Second Trimester

Nigerian Medical Practitioner Vol. 53 (1&2) 2008: pp. 3-6