the effect of vitamin d supplementation on serum and muscle irisin levels, and fndc5 expression in diabetic rats

Background: diabetes mellitus and metabolic disorders are a major burden on the healthcare system. irisin is a novel myokine reported to have beneficial effects on glucose and lipid metabolism. vitamin d deficiency has been implicated in the development of diabetes and hold a critical role in diabetes-related complications. in the present study, we examined the efficacy of vitamin d supplementation on serum irisin levels, skeletal muscle irisin levels, and the expression of the irisin precursor, fndc5 (fibronectin-type iii domain-containing 5) in type i diabetes mellitus rats.methods: thirty-six adult male sprague-dawley rats (150 – 250 g) were randomly divided into four groups: group i: healthy control rats with no treatment (n=8), group ii: healthy control rats receiving sesame oil as a placebo (n=8), group iii: diabetic rats receiving sesame oil as placebo (n=10), group iv: diabetic rats treated with 4300 iu/kg/week vitamin d (n=10). diabetes was induced by intraperitoneal (ip) injection of streptozotocin. at the end of the vitamin d intervention blood and triceps muscle samples were collected. rna was extracted from muscle and real-time pcr was performed to examine fndc5 gene expression.results: our study showed that the administration of vitamin d (4300 iu/kg/week) in a streptozotocin-diabetic rat model resulted in increased serum vitamin d levels, fndc5 gene expression and muscle irisin levels. however, the levels of serum irisin were not significantly changed by the administration of vitamin d.conclusions: in conclusion, we show that vitamin d supplementation enhances serum vitamin d levels, fdnc5 gene expression and muscle irisin levels in the streptozotocin-diabetic rat model. our study highlights the potential therapeutic effect of vitamin d supplementation for diabetes mellitus.