title: [Relationship of ionized calcium and 25-(OH) D in serum with obesity].
abstract: OBJECTIVE
  To investigate the relationship of ionized calcium and 25-(OH) D level in serum with obesity in order to provide theoretical basis for preventing obesity-related diseases.
  
  
  METHODS
  Base on a cross-sectional study, 169 overweight/obese subjects (92 men: age (37.76 +/- 17.56) years, 77 women: age (38.79 +/- 17.40) years) and 169 normal weight control subjects (92 men: age (36.24 +/- 17.28) years, 77 women: age (32.32 +/- 13.07) years) were selected in a 1:1 case-control matches. 25-(OH) D was assessed by ELISA. Serum ionized calcium was measured by flame atomic absorption spectrophotometry. The relationship of ionized calcium and 25-(OH) D level in serum with obesity was analyzed by using a Logistic regression model.
  
  
  RESULTS
  The average serum ionized calcium in overweight or obese subjects was(46.9 +/- 20.7) mg/L and that in normal control subjects was (63.2 +/- 19.5) mg/L (P < 0.001). Serum 25-(OH) D of overweight or obese was lower than normal control subjects ((48.3 +/- 16.7) nmmol/L vs. (63.8 +/- 35.4) nmmol/L, P < 0.001). Serum ionized calcium and 25-(OH) D was independently associated with body mass index in a logistic regression model [OR = 0.959, 95% CI 0.945-0.973; OR = 0.435, 95% CI 0.329-0.575].
  
  
  CONCLUSIONS
  Serum 25-(OH) D levels in obesity group was lower than that in control group. The results suggest that vitamin D might play an important role in the risk of developing obesity.
authors.affiliation: Department of Nutrition and Food Hygiene of Ningxia Medical University, Yinchuan 750004, China. yangjianjun_1969@163.com
authors.forename: Jianjun
authors.initials: J
authors.lastname: Yang
authors.forename: Pan
authors.initials: P
authors.lastname: Wang
authors.forename: Can
authors.initials: C
authors.lastname: Liu
authors.forename: Xiaoli
authors.initials: X
authors.lastname: He
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiujuan
authors.initials: X
authors.lastname: Tao
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhao
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D002112:Calcifediol / Q000097:blood*; D002118:Calcium / Q000097:blood*; D016022:Case-Control Studies; D002681:China; D003625:Data Collection; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood*; D012307:Risk Factors; D012494:Sampling Studies; D011795:Surveys and Questionnaires
chemical_list: D002112:Calcifediol; D002118:Calcium