Vitamin D deficiency and diabetes.
Vitamin D deficiency has been linked to the onset of diabetes. This review summarizes the role of Vitamin D in maintaining the normal release of insulin by the pancreatic beta cells (β-cells). Diabetes is initiated by the onset of insulin resistance. The β-cells can overcome this resistance by releasing more insulin, thus preventing hyperglycaemia. However, as this hyperactivity increases, the β-cells experience excessive Ca2+and reactive oxygen species (ROS) signalling that results in cell death and the onset of diabetes. Vitamin D deficiency contributes to both the initial insulin resistance and the subsequent onset of diabetes caused by β-cell death. Vitamin D acts to reduce inflammation, which is a major process in inducing insulin resistance. Vitamin D maintains the normal resting levels of both Ca2+and ROS that are elevated in the β-cells during diabetes. Vitamin D also has a very significant role in maintaining the epigenome. Epigenetic alterations are a feature of diabetes by which many diabetes-related genes are inactivated by hypermethylation. Vitamin D acts to prevent such hypermethylation by increasing the expression of the DNA demethylases that prevent hypermethylation of multiple gene promoter regions of many diabetes-related genes. What is remarkable is just how many cellular processes are maintained by Vitamin D. When Vitamin D is deficient, many of these processes begin to decline and this sets the stage for the onset of diseases such as diabetes.
The Babraham Institute, Babraham, Cambridge CB22 3AT, U.K. michael.berridge@babraham.ac.uk.
Michael J
MJ
Berridge
D000818:Animals; D017209:Apoptosis; D020013:Calcium Signaling; D019175:DNA Methylation; D003922:Diabetes Mellitus, Type 1 / Q000209:etiology / Q000517:prevention & control*; D003924:Diabetes Mellitus, Type 2 / Q000209:etiology / Q000517:prevention & control*; D019587:Dietary Supplements; D044127:Epigenesis, Genetic; D019317:Evidence-Based Medicine; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000378:metabolism / Q000473:pathology; D018384:Oxidative Stress; D014807:Vitamin D / Q000627:therapeutic use*; D014808:Vitamin D Deficiency / Q000178:diet therapy* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology
D007328:Insulin; D014807:Vitamin D
Vitamin D; calcium; diabetes