Pyridoxal, Vitamin B12 and folate metabolism women taking oral contraceptive agents

Abstract

Serum pyridoxal. vitamin B₁₂ serum and red cell folate and haemoglobin levels were measured in a large group of women taking part in the Busselton population survey to determine the effect of oral contraceptive agents on these measurements. Serum pyridoxal levels were measured in 107 women taking oral contraceptive agents. and compared with the results obtained from 107 age-matched non-pregnant women who were not taking these agents. The mean serum levels for the two groups were not significantly different. Nine per cent of women taking oral contraceptive agents had a serum pyridoxal below the lower limit of the reference range. compared with 13% in the controls. Blood was available from 1 067 non-pregnant women for the measurement of serum vitamin B₁₂ serum and red cell folate and haemoglobin levels; 166 of them were taking oral contraceptive agents. The group taking oral contraceptive agents had significantly lower mean concentrations of vitamin B_I2 and serum and red cell folate. The mean haemoglobin level was the same in both groups (13.3 g/100 ml). The low mean red cell folate suggests that the available folate pool in women taking oral contraceptive agents is significantly lowered. There were fewer women with serum folate and pyridoxal levels below the lower limit of the reference range in the group taking oral contraceptive agents than in the controls. This was no doubt due to the inclusion of a greater number of women of relatively low economic status in the controls. since oral contraceptive agents are not subsidised by the Health Service in Australia.

S. Afr. Med. J 48, 1937 (1974).