Hepatic metabolism of vitamin D3 in streptozotocin-induced diabetic rat

The effect of streptozotocin-induced diabetes on the in vitro conversion of vitamin D3 to 25-hydroxy-vitamin D3 (25-OHD3) by isolated liver microsomes from rachitic rats was examined. Enzymic activity was significantly less than that observed in control animals (P less than 0.001). Administration of insulin restored activity almost to control values. These findings provide evidence that diabetes in this animal model produces alterations in the metabolism of vitamin D.