In conclusion , the deficiency of vitamin D is associated with an increased level of BMI in the studies of both diabetic and non-diabetic subjects .
The deficiency of vitamin D is prevalent all over the world .
Studies have shown that vitamin D may play an important role in the development of obesity .
The current study was conducted to quantitatively evaluate the association between serum 25-(OH ) vitamin D levels  and the risk of obesity in both diabetic and non-diabetic subjects .
Association of vitamin D deficiency with incidence of type 2 diabetes in high-risk Asian subjects.
BACKGROUND Recent studies suggest an association between 25-hydroxyvitamin D [ 25(OH)D ] and type 2 diabetes ( T2D ) risk . However , prospect i ve studies investigating the relation between vitamin D inadequacy and incidence of T2D incorporating obesity and dynamic measures of insulin resistance ( IR ) and pancreatic β cell function are limited . OBJECTIVE We tested the hypothesis that baseline 25(OH)D is associated with the incidence of T2D in high-risk subjects for up to 5 y of follow-up , independently of obesity , baseline IR , and β cell function . DESIGN We recruited 1080 nondiabetic Korean subjects [ mean ± SD age : 49.5 ± 11.4 y ] based on the presence of one or more risk factors for T2D , including obesity , hypertension , dyslipidemia , and /or family history of T2D . We measured anthropometric and biochemical indicators , HOMA2-IR , and the insulinogenic index ( IGI ; calculated as change in insulin at 30 min/change in glucose at 30 min ) from a 75-g oral-glucose-tolerance test . RESULTS Of the participants , 10.5 % had a serum 25(OH)D deficiency ( < 10 ng/mL ) , 51.6 % had an insufficiency ( 10.0 - 19.9 ng/mL ) , and 38.0 % had a sufficiency ( ≥20 ng/mL ) , and the incidence of T2D at 32.3 ± 15.6 mo ( ±SD ) declined accordingly : 15.9 % , 10.2 % , and 5.4 % , respectively ( P < 0.001 ) . After adjustment for age , sex , blood pressure , lifestyles , family history , season , parathyroid hormone , and high-sensitivity C-reactive protein , the participants with 25(OH)D deficiency had an increased risk of T2D independently of BMI , HOMA2-IR , and IGI ; the HRs were 2.06 ( 95 % CI : 1.22 , 3.49 ) for 25(OH)D 10 - 19.9 ng/mL compared with ≥20 ng/mL and 3.23 ( 95 % CI : 1.66 , 6.30 ) for 25(OH)D < 10 ng/mL compared with ≥20 ng/mL. CONCLUSION The current prospect i ve study suggests that vitamin D metabolism may play a role in T2D pathogenesis independently of known risk factors . This trial was registered at clinical trials.gov as NCT01508481
In conclusion , the deficiency of vitamin D is associated with an increased level of BMI in the studies of both diabetic and non-diabetic subjects .
The deficiency of vitamin D is prevalent all over the world .
Studies have shown that vitamin D may play an important role in the development of obesity .
The current study was conducted to quantitatively evaluate the association between serum 25-(OH ) vitamin D levels  and the risk of obesity in both diabetic and non-diabetic subjects .