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 .
Effect of vitamin D supplementation on selected inflammatory biomarkers in older adults: a secondary analysis of data from a randomised, placebo-controlled trial.
Observational studies have suggested that 25-hydroxyvitamin D ( 25(OH)D ) levels are associated with inflammatory markers . Most trials reporting significant associations between vitamin D intake and inflammatory markers used specific patient groups . Thus , we aim ed to determine the effect of supplementary vitamin D using secondary data from a population -based , r and omised , placebo-controlled , double-blind trial ( Pilot D-Health trial 2010/0423 ) . Participants were 60- to 84-year-old residents of one of the four eastern states of Australia . They were r and omly selected from the electoral roll and were r and omised to one of three trial arms : placebo ( n 214 ) , 750 μg ( n 215 ) or 1500 μg ( n 215 ) vitamin D3 , each taken once per month for 12 months . Post-intervention blood sample s for the analysis of C-reactive protein ( CRP ) , IL-6 , IL-10 , leptin and adiponectin levels were available for 613 participants . Associations between intervention group and biomarker levels were evaluated using quantile regression . There were no statistically significant differences in distributions of CRP , leptin , adiponectin , leptin : adiponectin ratio or IL-10 levels between the placebo group and either supplemented group . The 75th percentile IL-6 level was 2·8 pg/ml higher ( 95 % CI 0·4 , 5·8 pg/ml ) in the 1500 μg group than in the placebo group ( 75th percentiles:11·0 v. 8·2 pg/ml ) , with a somewhat smaller , non-significant difference in 75th percentiles between the 750 μg and placebo groups . Despite large differences in serum 25(OH)D levels between the three groups after 12 months of supplementation , we found little evidence of an effect of vitamin D supplementation on cytokine or adipokine levels , with the possible exception of IL-6
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 .