Analysis of the relationship between obesity and vitamin D

According to the definition of World Health Organization (WHO), obesity is the excessive accumulation of fat tissue in the body. İn developed countries, as well as in already developing countries, especialy due to the expansion of the western lifestyle, the prevalence of obesity is increasing at high rates. Vitamin D and its physiological effects on bone, intestine, kidney and the parathyroid glands in which is a fat-soluble vitamin which regulates the phosphorus metabolism. At present, vitamin D deficiency is quite common. In studies, on obese individuals reported that vitamin D deficiency is more common. In our study here, we investigated the relationship between Body Mass Index (BMI) and 25-hydroxyvitamin D (25(OH)D). In this study, conducted at Evliya Çelebi Dumlupınar University Training and Research Hospital between December 2013 and February 2014, the 259 volunteers enrolled were living in Kütahya and all of the participants were women. Our working group was divided into two groups considering the body mass index in obese and non-obese (control). None of the participants were taking any vitamin D, calcium, vitamin D + calcium supplements or multivitamins. Our age limits were between premenopausal and menopausal period. Obesity group which it is BMI was above 30 kg / m2 was formed with 127 participants and non-obese control group which it is BMI was above 25 kg / m2 was composed of 132 participants. Serum total 25(OH)D (25(OH)D2 + 25(OH)D3 in total) and serum intact parathyroid hormone (iPTH) levels were measured. According to the obtained results, in both groups, serum 25(OH)D level of 64.9% were determined deficienct and 30.9% were insufficient and 4.2% was at the limit. Deficiency of 25 (OH) D compared to non-obese group (51.5%, n = 68) was higher in the obese group (78.7%, n = 100). 6.9% of both serum iPTH levels of our groups were below the referencerange, 64.9% of it was at the reference range and 38.2% of it was above the reference range. However, serum iPTH levels of the obese group, (370%, n = 47) compared to non-obese group (7.19, n = 26), was found in the upper reference range. Statistically significant differences was found between 25(OH)D and iPTH levels of the control group and obesity group (p < 0.001). Similarly, positive correlation was found between BMI and iPTH levels (r = 0.336; p < 0.001), serum 25 (OH) D levels and BMI (r = -0295; p <0.001) and between age of the participants and of serum 25 (OH) D levels (r = - 0.681; p <0.001). Key Words: 25-Hydroxyvitamin D, obesıty, intact parathyroid hormone, body mass index.