1,25-Dihydroxycholecalciferol in dialysed patients with clinically asymptomatic renal osteodystrophy. A controlled study

Chronic renal failure and vitamin D metabolites: a status report

Seventeen undialysed adult patients with chronic renal failure took part in a controlled study of the effects of 1,25(OH)2D3 and D3. After a 6-month observation period the patients were allocated at random to 2 groups for 6 months of treatment with either 1,25(OH)2D3 (mean dose 0.5 micrograms daily) or D3 (dose 100 micrograms daily). Treatment was then discontinued and the patients were studied for a further 3 months. The patients as a group initially had a moderate renal osteodystrophy. During treatment serum iPTH decreased in both groups but most markedly in the 1,25(OH)2D3 group in which the iPTH values became normal. Serum creatinine increased during treatment in both groups, in the group receiving 1,25(OH)2D3 this was coupled with an increase in serum calcium to within the normal range. Our data demonstrate that 1,25(OH)2D3 treatment in patients with chronic renal failure leads to a further reduction in renal function, which may be partially reversible. Physicians should therefore be reluctant to give vitamin D analogues to patients with chronic renal failure unless they have severe symptomatic renal osteodystrophy.

A possible direct effect of 24,25-dihydroxycholecalciferol on the parathyroid gland in patients with chronic renal failure

Seventeen undialysed adult patients with chronic renal failure took part in a controlled study of the effects of 1,25(OH)2D3 and D3. After a 6-month observation period the patients were allocated at random to two groups for 6 months of treatment with either 1,25(OH)2D3 (mean dose 0.5 microgram daily) or D3 (dose 100 microgram daily). The treatment was then discontinued and the patients were studied for a further 3 months. In the 1,25(OH)2D3 group the mean serum concentration of 1,25(OH)2D rose significantly during treatment, whereas serum concentratins of 25OHD and 24,25(OH)2D remained unchanged. In the D3 group there was a highly significant increase in serum concentrations of 25OHD and 24,25(OH)2D, whereas serum 1,25(OH)2D remained unchanged. There was a significant fall in serum iPTH in both treatment groups. This fall was unrelated to serum calcium in the D3 group unlike the findings in the 1,25(OH)2D3 group. The data support previous experimental evidence that serum iPTH can be suppressed by 24,25(OH)2D3 and suggest that this analogue may be of clinical importance in the treatment of chronic renal failure without inducing hypercalcaemia.

Is 1,25-dihydroxy-cholecalciferol harmful to renal function in patients with chronic renal failure?

Seventeen undialysed adult patients with chronic renal failure took part in a controlled study of the effects of 1,25(OH)2D3 and D3. After a 6-month observation period the patients were allocated at random to two groups for 6 months of treatment with either 1,25(OH)2D3 (mean dose 0.5 microgram daily) or D3 (dose 100 microgram daily). Treatment was then discontinued and the patients were studied for a further 6 months. Serum iPTH was decreased in both groups but most markedly in the 1,25(OH)2D3 group in which the iPTH values became normal. Serum creatinine increased during treatment in both groups. In the group receiving 1,25(OH)2D3 this was coupled to an increase in serum calcium within the normal range. Our data demonstrate that 1,25(OH)2D3 treatment in patients with chronic renal failure leads to a further reduction in renal function, which may be partially reversible. Physicians should therefore be reluctant to give vitamin D analogues to patients with chronic renal failure unless they have severe symptomatic renal osteodystrophy.