Association of body mass index and serum vitamin D level in healthy Iranian adolescents.

INTRODUCTION

In studies of obese adolescents in various countries, vitamin D deficiency has been correlated with greater weight and elevated BMI. However, there is insufficient data on the relation between vitamin D status and body fat indexes in adolescence. The aim of this study was to investigate the association of serum (25[OH]D) concentrations with body mass index of healthy Iranian subjects to understand whether specific data on the relation between vitamin D status and body mass index is common in all populations.

MATERIAL AND METHODS

Data was collected from 259 ambulant medical staff adults, students and other subjects who met the inclusion criteria of the study. Body mass index and fasting 25-Hydroxy vitamin D level were measured. Vitamin D deficiency was defined as having a 25(OH)D concentration 〈 25 nmol/L.

RESULTS

Participants were aged 20-64 years, mean age 34 ± 9 years, and about 57.5% of the participants were women. The mean (± SD) body mass index (kg/m2) was 24.2 ± 3.8 kg/m2 (median = 23.7 kg/m2), the mean (± SD) vitamin D level of the participants was 29 ± 16 nmol/L (median = 26 nmol/L), and 48% of the participants had vitamin D deficiency. In this study, there was no significant association between vitamin D level and BMI (r = 0.064; p = 0.307) (age adjusted). Moreover, there was no association between vitamin D level and sex of the participants. In addition, no association between BMI and sex of the adolescents was seen (p; NS), but a significant association between age and vitamin D level was found (r = 0.002).

CONCLUSION

Our data suggests that various mechanisms could potentially contribute to the robust association of vitamin D with adiposity; in normal or near normal BMI, vitamin D status may not be correlated with age.