Effect of vitamin D intervention on the outcome of glucose metabolism in patients with impaired glucose regulation

Objective To explore the intervention effect of low-dose vitamin D on glucose metabolism of patients with impaired glucose regulation. Methods A total of 196 subjects receiving oral glucose tolerance test were enrolled in this study, including individuals with normal glucose tolerance (NGT group, n=67) and individuals with impaired glucose regulation (IGR group, n=129). The IGR group was divided into intervention group (n=64)and non-intervention group (n=65) according to vitamin D intervention (for 1 year) performed or not. Clinical data and biochemical parameters were collected. Results The level of serum 25(OH)D3 was significantly lower in the IGR group than that of normal control group (P<0.05). After 1 year of low-dose vitamin D intervention, insulin sensitivity increased and insulin resistance decreased in the intervention group as compared with non-intervention group. Diabetes developed less frequently in the intervention group (25 of 64 [39.1%]) compared with non-intervention group (30 of 65 [46.2%]). But there was no significant different in diabetes prevalence between the two groups. Conclusions Vitamin D intervention can improve insulin sensitivity and reduce insulin resistance in patients with impaired glucose regulation. Low dose vitamin D can improve the abnormal glucose metabolism outcome in patients with impaired glucose regulation. Key words: vitamin D; 25(OH)D3; type 2 diabetes mellitus; insulin secretion