Vitamin D Deficiency and Type 2 Diabetes Mellitus

Vitamin D has skeletal as well as non-skeletal effects including those on the endocrine system. Diabetes Mellitus, a leading cause of morbidity and mortality, has recently been linked to vitamin D status. It has been suggested that vitamin D deficiency is one of the modifiable risk factors for diabetes. We therefore designed this study to look at the relationship between vitamin D levels and diabetes control in type 2 South Asian diabetics from Pakistan. The objective of the study was to determine if correcting vitamin D deficiency improves diabetes control in type 2 diabetics. This analytical cross-sectional study, with prospective follow-up, included 200 subjects with type 2 diabetes (age range 27-76 years), who were deficient in vitamin D. 100 of these were treated with vitamin D and were assigned to the study group, while the rest did not receive treatment with vitamin D and so were placed in the control group. The subjects had their history taken and underwent clinical examination, after which, fasting blood was analyzed for HbA1C (using high performance liquid chromatography) and vitamin D levels (by the chemiluminescence technique) at baseline. Then the subjects in the study group only, were given vitamin D treatment for three months, after which, HbA1C and vitamin D levels were rechecked in both groups. In the study group, compared to baseline, the vitamin D levels at 3 months (following vitamin D supplementation) had significantly increased (p < 0.001) accompanied by significant decrease in HbA1C values (P < 0.001). In the control group, at three months, there was no significant change (p = 0.219) in vitamin D levels, but there was significant increase in HbA1C levels (p < 0.001) compared to baseline. These results indicate that correcting vitamin D deficiency improves diabetes control in type 2 diabetics. Larger prospective studies are required in the SouthAsian population to corroborate our findings.