title: Vitamin D Supplementation and High-Density Lipoprotein Cholesterol: A Study in Healthy School Children.
abstract: BACKGROUND
  The high-density lipoprotein cholesterol (HDL-C) level has been shown to have a significant role in the prevention of cardiovascular diseases and atherosclerosis. Low vitamin D levels have been shown to be correlated with dyslipidemia, but limited data exist on indigenous children.
  
  
  OBJECTIVE
  We aimed to investigate the effect of vitamin D supplementation on HDL-C levels in school-aged Iranian children.
  
  
  METHODS
  In this prospective controlled clinical trial, 47 healthy children (23 boys) aged 10 - 14 years, students of Birjand (Iran) elementary schools, were selected and randomly divided into two groups. The study group received a vitamin D supplement (1000 mg capsule) daily for one month, and placebo tablets were prescribed to the controls. Before and after the treatment course, the serum HDL-C and 25-hydroxy vitamin D levels of both groups were measured. The data were analyzed by SPSS, ver. 16, and Chi-square tests, Fisher's exact test, paired-sample t-tests, and Pearson's correlation were used, wherever appropriate. The significance level was set at P < 0.05.
  
  
  RESULTS
  Forty children completed the study; their mean age was 11.5 ± 1.175 years. The mean serum levels of both HDL-C and vitamin D showed a significant rise following the treatment in the study group (P = 0.007 and P < 0.001, respectively), whereas both variables decreased slightly in the control group (P = 0.27). There was no statistically significant difference in the mean serum levels of HDL-C and vitamin D between the two groups after the intervention (P = 0.11 and P = 0.20, respectively).
  
  
  CONCLUSIONS
  Vitamin D supplements seem to have a positive impact on serum HDL-C levels and may be effective in reducing the risk of cardiovascular diseases in the long term.
authors.affiliation: Department of Pediatrics, Atherosclerosis and Coronary Artery Research Center, Birjand University of Medical Sciences, Birjand, IR Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Tavakoli
authors.affiliation: Department of Pediatrics, Atherosclerosis and Coronary Artery Research Center, Birjand University of Medical Sciences, Birjand, IR Iran.
authors.forename: Kokab
authors.initials: K
authors.lastname: Namakin
authors.affiliation: Department of Pathology, School of Medicine, Birjand University of Medical Sciences, Birjand, IR Iran.
authors.forename: Mahmood
authors.initials: M
authors.lastname: Zardast
keywords: Atherosclerosis; Children; High-Density Lipoprotein Cholesterol (HDL-C); Vitamin D