effect of vitamin d on glucose homeostasis and insulin sensitivity and resistance in type 2 diabetes: a systematic review

Context: in recent years, non-bone diseases have been shown associated with vitamin d deficiency, of which type 2 diabetes is a group of metabolic disorders caused by insulin deficiency. vitamin d deficiency affects the metabolic function of the cells, including beta-pancreatic cells. regarding the effectiveness of vitamin d to control type 2 diabetes, the present study aimed at reviewing the relationship between vitamin d, glucose homeostasis, and insulin resistance in type 2 diabetes. evidence acquisition: in this review, descriptive and analytic studies were analyzed using biochemical tests, questionnaires, and interviews. using the keywords, such as vitamin d, type 2 diabetes, and insulin resistance, 11 articles, including descriptive-analytic, cross-sectional, case-control and interventional studies published from 1986 to 2018 were included. results: the levels of 25-hydroxyvitamin d in diabetics, women, and obese people are lower than others, which can indicate the effect of vitamin d on glucose homeostasis. in addition, vitamin d affects intracellular calcium, and, consequently insulin secretion. it can be said that vitamin d deficiency can make calcium unable to regulate insulin secretion. conclusions: according to the studies, it can be concluded that vitamin d can be effective to prevent and control type 2 diabetes. also, there is no association between vitamin d and insulin secreted by food and hemoglobin a1c.