The present results indicate that while treatment with 1,25D3 had practically no effect on non-diabetic rats, the same treatment in streptozotocin-induced diabetic rats corrected in part the over-expression of the IR gene in liver and adipose tissue, although it did not revert the hyperglycemia, hypoinsulinemia, glycosuria or ketonemia of these diabetic animals. This evidence concerns the gene INSR and Hypoinsulinemia.