1. In vitro activation of erythrocyte aspartate aminotransferase (EC 2.6.1.1) activity by pyridoxal phosphate was used to assess vitamin B4 nutritional status in forty Sudanese women taking combined, low-dose oral contraceptives (oestrogen-progestogen; OC) and in thirty healthy, non-pregnant women not taking OC.
2. Fourteen (35%) out of forty OC users showed apparent vitamin B4 deficiency.
3. Side-effects associated with OC were more common among the apparently vitamin-B4-deficient OC users than among OC users and non-OC users not deficient in vitamin B4.