Vitamin-D deficiency in the osteomalacia of chronic renal failure

The plasma level of 25-hydroxy-vitamin D (25-OHD) has been measured and the histological appearances of bone examined in 22 patients with stable chronic renal failure. The results show that osteomalacia occurred only in those patients with relatively low levels of 25-OHD. It is concluded that the osteomalacia of chronic renal failure results from a lack of 25-hydroxy-vitamin D3 superimposed on an existing deficiency of 1,25-dihydroxy-vitamin D3 (1,25-(OH)2D3) rather than from lack of 1,25-(OH)2D3 alone.