The vitamin status (vitamins A, E, C, Carotene, B1, B2 and B6) of 18 patients receiving maintenance haemodialysis was assessed. All patients were receiving vitamin B1, B2 and B6 supplements and the effect of stopping these supplements on subsequent vitamin status was further studied. Apart from vitamin A, which was significantly increased in all patients, the mean level of all other vitamins was similar to the control group. Despite these normal group means, individual patients could be identified with low or marginally low vitamin C and B2 levels. When the vitamin B complex supplements were stopped, vitamin B2 and B6 remained normal over the subsequent six months maintenance haemodialysis but there was deterioration in vitamin B2 status. Leucocyte vitamin C levels responded well to oral supplements of 400 mg vitamin C per day. This study suggests that vitamin C and B2 supplements are necessary in patients receiving maintenance haemodialysis, other vitamin supplements being unnecessary.