Is vitamin D deficiency an independent risk factor for obesity and abdominal obesity in women?

Vitamin D has been determined to have some effects on b cell function and insulin sensitivity, and it is known that type 2 diabetes mellitus and hyperparathyroidism can cause obesity. The aim of our study was to investigate if vitamin D deficiency without diabetes mellitus and metabolic syndrome is associated with obesity and abdominal obesity.

The study included 276 healthy premenopausal women. To exclude other causes of obesity, postmenopausal women and subjects with diabetes mellitus and metabolic syndrome were excluded. Women were divided into two groups depending on their 25-hydroxyvitaminD(3) [25(OH)D(3)] levels: subjects with vitamin D deficiency (Group 1) and subjects without vitamin D deficiency (Group 2). Body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (WHR) were compared between the two groups.

BMI, WC, WHR, rates of obesity, and abdominal obesity according to WC and WHR of Group 2 were lower than those of Group 1 (p = 0.0005, p = 0.0001, p = 0.0045, p = 0.032, p = 0.002, p = 0.011, respectively). 25(OH)D(3) levels negatively correlated with BMIs (r = -0.480, p < 0.0001), WCs (r = -0.480, p < 0.0001) and WHRs (r = -0.312, p < 0.05). There were no differences between serum parathormone, calcium and phosphorus levels of Group 1 and 2 (p = 0.239, p = 0.354, p = 0.95, respectively).

Vitamin D deficiency without diabetes mellitus and hyperparathyroidism may be associated with obesity and abdominal obesity.