title: Vitamin D status and cardiometabolic risk factors across latitudinal gradient in Iranian adults: National food and nutrition surveillance.
abstract: BACKGROUND
  This study aimed to evaluate the vitamin D status in an adult population across latitudinal gradient and to investigate its possible associations with certain cardiometabolic risk factors.
  
  
  METHODS
  A total of 1406 healthy subjects aged 19-60 years were randomly selected from six regions of Iran across latitudinal gradient from 29° N to 37.5° N. Anthropometric and biochemical assessments were performed. The combination of high body mass index (>25 kg/m2), low high-density lipoprotein cholesterol (< 40 mg/dl in males and < 50 mg/dl in females) and high triglycerides (> 150 mg/dl) was defined as cardiometabolic risk factors.
  
  
  RESULTS
  The mean concentration of serum 25-hydroxycalciferol (25(OH)D) was 26.8±17.7 nmol/l. There were no significant differences in the mean serum 25(OH)D levels among different latitudes. Undesirable vitamin D status (deficiency and insufficiency) was found in 90.7% of the subjects. After adjustment for age and gender, the association between weight status and serum 25(OH)D was significant ( p< 0.04, odds ratio:1.49; confidence interval: 1.01-2.19). The prevalence of cardiometabolic risk factors among the subjects with serum 25(OH)D less than 27.5 nmol/l was significantly higher than those with serum calcidiol concentrations above 27.5 nmol/l (13.3% vs. 10.0%, p = 0.033).
  
  
  CONCLUSIONS
  Undesirable vitamin D status is highly prevalent among Iranian adults of both sexes irrespective of latitude and even in sunny regions. The occurrence of cardiometabolic risk factors was significantly higher in those subjects with circulating calcidiol concentrations below 27.5 nmol/l.
authors.affiliation: 1 Laboratory of Nutrition Research, National Nutrition and Food Technology Research Institute and Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Bahareh
authors.initials: B
authors.lastname: Nikooyeh
authors.affiliation: 2 Nutrition Office, Iran Ministry of Health, Treatment and Medical Education, Tehran, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Abdollahi
authors.affiliation: 3 Department of Nutritional Policy-Making Research, National Nutrition and Food Technology Research Institute and Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Majid
authors.initials: M
authors.lastname: Hajifaraji
authors.affiliation: 4 Department of Biostatistics, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Hamid
authors.initials: H
authors.lastname: Alavi-Majd
authors.affiliation: 2 Nutrition Office, Iran Ministry of Health, Treatment and Medical Education, Tehran, Iran.
authors.forename: Forouzan
authors.initials: F
authors.lastname: Salehi
authors.affiliation: 5 UNICEF Office, Tehran, Iran.
authors.forename: Amir Hossein
authors.initials: AH
authors.lastname: Yarparvar
authors.affiliation: 1 Laboratory of Nutrition Research, National Nutrition and Food Technology Research Institute and Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Tirang R
authors.initials: TR
authors.lastname: Neyestani
mesh_terms: D000328:Adult; D015992:Body Mass Index; D002112:Calcifediol / Q000097:blood; D002318:Cardiovascular Diseases / Q000097:blood / Q000453:epidemiology*; D002784:Cholesterol / Q000097:blood; D005260:Female; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000453:epidemiology*; D008875:Middle Aged; D009749:Nutrition Surveys; D009752:Nutritional Status; D015995:Prevalence; D012307:Risk Factors; D012621:Seasons; D013472:Sunlight; D014280:Triglycerides / Q000097:blood; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*; D055815:Young Adult
chemical_list: D014280:Triglycerides; D014807:Vitamin D; D002784:Cholesterol; D002112:Calcifediol
keywords: 25(OH)D; Vitamin D; blood lipids; cardiometabolic risk factors; latitude