The effect of Vitamin D on testosterone and uncarboxylated osteocalcin levels in aged male rats.

There is a well-established complex interaction between vitamin D metabolism and bone and gonad functions. In this study, we aimed to investigate the potential effects of vitamin D therapy on testosterone and osteocalcin (OC) levels in aged male rats. Forty-five adult male rats were divided into three groups in this study. Unlike the control group, the two experimental groups received 50 IU/kg/day and 100 IU/kg/day of vitamin D (cholecalciferol), respectively, for a 4-week period using the gavage method. Testicular tissue and blood samples from rats were collected under general anesthesia at the end of the 4-week period. Testicular tissue samples were examined using light and electron microscopy. Additionally, serum testosterone and OC levels were measured in blood samples. The 50 IU/kg dose of cholecalciferol increased testosterone and OC levels, which were lower than normal due to aging, and regulated the organization of the seminiferous tubule epithelium and interstitium more effectively than the 100 IU/kg dose of cholecalciferol. Male fertility functions and bone health, which degrade due to aging, were increased due to the use of exogenous vitamin D, although the higher dose was not associated with more effective results.