Current evidence indicates that inverse association between leptin level and 25(OH)D concentration was observed in observational studies , which was not demonstrated in intervention studies with high heterogeneity .
We aim ed to investigate the potential association between vitamin D and serum leptin levels by pooling together the results from observational studies and clinical trials .
Cross-sectional and longitudinal relation between serum 25-hydroxyvitamin D and body mass index: the Tromsø study
Purpose The serum 25-hydroxyvitamin D ( 25(OH)D ) levels are lower in obese than lean subjects . The present study examines the cross-sectional and longitudinal relations between body mass index ( BMI ) and serum 25(OH)D , and the serum 25(OH)D response to vitamin D supplementation  in relation to BMI . Methods The Tromsø study is a longitudinal population -based multi purpose study . The fourth survey was conducted in 1994 and the sixth in 2008 . The intervention study was a 1-year placebo-controlled r and omized intervention trial , where the results from the 93 subjects given 40,000 IU per week are presented . Results A total of 10,229 subjects were included in the 2008 cross-sectional study . There was a significant negative association between serum 25(OH)D levels and BMI which was also present during the winter months . Serum 25(OH)D levels varied through seasons , but not BMI . In the longitudinal study from 1994 to 2008 which included 2,656 subjects , change in BMI was a significant negative predictor of change in 25(OH)D. In the intervention study , there was a significant and negative correlation between BMI and serum 25(OH)D both at baseline and at the end of the study . The increase in serum 25(OH)D after 1 year was significantly and inversely related to baseline BMI . Conclusions We have confirmed the strong association between serum 25(OH)D and BMI . The very obese need higher vitamin D doses than lean subjects to achieve the same serum 25(OH)D levels
Current evidence indicates that inverse association between leptin level and 25(OH)D concentration was observed in observational studies , which was not demonstrated in intervention studies with high heterogeneity .
We aim ed to investigate the potential association between vitamin D and serum leptin levels by pooling together the results from observational studies and clinical trials .