title: Calcium-vitamin D cosupplementation influences circulating inflammatory biomarkers and adipocytokines in vitamin D-insufficient diabetics: a randomized controlled clinical trial.
abstract: BACKGROUND
  To the best of our knowledge, no study has examined the effects of vitamin D-calcium cosupplementation on inflammatory biomarkers and adipocytokines in vitamin D-insufficient type 2 diabetics.
  
  
  OBJECTIVE
  This study was performed to assess the effects of vitamin D and calcium supplementation on inflammatory biomarkers and adipocytokines in vitamin D-insufficient people with type 2 diabetes.
  
  
  METHODS
  Totally, 118 diabetic patients were enrolled in this randomized, placebo-controlled clinical trial. After matching for age, sex, body mass index, type and dose of hypoglycemic agents, and duration of diabetes, subjects were randomly assigned into 4 groups receiving the following: 1) 50000 IU/wk vitamin D + calcium placebo; 2) 1000 mg/d calcium + vitamin D placebo; 3) 50 000 IU/wk vitamin D + 1000 mg/d calcium; or 4) vitamin D placebo + calcium placebo for 8 weeks. Blood sampling was done for the quantification of inflammatory biomarkers and adipocytokines at the study baseline and after 8 weeks of intervention.
  
  
  RESULTS
  Calcium (changes from baseline: -75 ± 19 ng/ml, P = .01) and vitamin D alone (-56 ± 19 ng/mL, P = .01) and joint calcium-vitamin D supplementation (-92 ± 19 ng/mL, P = .01) resulted in a significant reduction in serum leptin levels compared with placebo (-9 ± 18 ng/mL). This was also the case for serum IL-6, such that calcium (-2 ± 1 pg/mL, P < .001) and vitamin D alone (-4 ± 1 pg/mL, P < .001) and their combination (-4 ± 1 pg/mL, P < .001) led to significant reductions compared with placebo (3 ± 1 pg/mL). After adjustment for potential confounders, individuals in the calcium (-3.1 ± 1.3, P < .05), vitamin D (-3.1 ± 1.3, P < .05), and joint calcium-vitamin D groups (-3.4 ± 1.3, P < .05) had greater reductions in serum TNF-α concentrations compared with placebo (0.1 ± 1.2). Individuals who received joint calcium-vitamin D supplements tended to have a decrease in serum high-sensitivity C-reactive protein levels compared with placebo after controlling for baseline levels (-1.14 ± 0.25 vs 0.02 ± 0.24 ng/mL, P = .09).
  
  
  CONCLUSIONS
  Joint calcium-vitamin D supplementation might improve systemic inflammation through decreasing IL-6 and TNF-α concentrations in vitamin D-insufficient people with type 2 diabetes.
authors.affiliation: Food Security Research Center (Marj.T., L.A., Mary.T., A.E.), Department of Community Nutrition (Marj.T., L.A., A.E.), School of Nutrition and Food Science, and Isfahan Endocrine and Metabolism Research Center (E.F.), Isfahan University of Medical Sciences, Isfahan 81745-151, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Tabesh
authors.forename: Leila
authors.initials: L
authors.lastname: Azadbakht
authors.forename: Elham
authors.initials: E
authors.lastname: Faghihimani
authors.forename: Marjan
authors.initials: M
authors.lastname: Tabesh
authors.forename: Ahmad
authors.initials: A
authors.lastname: Esmaillzadeh
mesh_terms: D054392:Adipokines / Q000097:blood*; D000368:Aged; D015415:Biomarkers / Q000097:blood*; D002097:C-Reactive Protein / Q000378:metabolism; D002136:Calcium, Dietary / Q000627:therapeutic use*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000188:drug therapy*; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood*; D008297:Male; D008875:Middle Aged; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D014807:Vitamin D / Q000627:therapeutic use*; D014808:Vitamin D Deficiency / Q000097:blood*; D014815:Vitamins / Q000627:therapeutic use*
chemical_list: D054392:Adipokines; D015415:Biomarkers; D002136:Calcium, Dietary; D014409:Tumor Necrosis Factor-alpha; D014815:Vitamins; D014807:Vitamin D; D002097:C-Reactive Protein