title: Sunlight increases serum 25(OH) vitamin D concentration whereas 1,25(OH)2D3 is unaffected. Results from a general population study in Göteborg, Sweden (The WHO MONICA Project).
abstract: OBJECTIVE
  To determine serum 25-hydroxyvitamin D3 [25(OH)D3] and its 1-hydroxylated metabolite [1,25(OH)2D3] and relate them to anthropometric data, life-style habits, blood pressure and selected biochemical analytes.
  
  
  METHODS
  Random population samples of men and women.
  
  
  METHODS
  Göteborg, Sweden, population size 450,000 inhabitants. The study was performed within the framework of the WHO MONICA Project.
  
  
  METHODS
  2000 randomly selected subjects were invited to the main MONICA screening. Out of those 1421 (71%) participated. Fifty individuals in each of four age-groups, 25-64 years, were selected at random for the present analyses (184 men and 198 women).
  
  
  RESULTS
  The concentration of 25(OH)D3 was similar in both sexes whereas 1,25(OH)2D3 concentration was higher in women than in men (P = 0.01). 25(OH)D3 correlated positively to sun exposure, physical activity and negatively to intact parathyroid hormone (PTH) in both sexes, and also negatively to blood pressure in men. The remaining significant relationship for 25(OH)D3, when age and sun exposure were taken into account in multivariate analyses, was a negative correlation to intact PTH in both sexes. 1,25(OH)2D3 correlated positively to intact PTH in both men and women, negatively to height in men, positively to fibrinogen in men and positively to psychological stress and osteocalcin in women. When all variables were included in multivariate analyses 1,25(OH)2D3 concentration correlated negatively to age and positively to intact PTH and osteocalcin in both sexes together.
  
  
  CONCLUSIONS
  Sunlight was the only external factor that influenced 25(OH)D3 concentration whereas 1,25(OH)2D3 was unaffected by sun exposure. 1,25(OH)2D3 was not related to environmental or life style factors but declined by age and correlated positively to intact PTH and osteocalcin.
  
  
  BACKGROUND
  Grants from the Swedish Medical Research Council and the Swedish Heart and Lung Foundation.
authors.affiliation: Department of Medicine, Göteborg University, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Landin-Wilhelmsen
authors.forename: L
authors.initials: L
authors.lastname: Wilhelmsen
authors.forename: J
authors.initials: J
authors.lastname: Wilske
authors.forename: G
authors.initials: G
authors.lastname: Lappas
authors.forename: T
authors.initials: T
authors.lastname: Rosén
authors.forename: G
authors.initials: G
authors.lastname: Lindstedt
authors.forename: P A
authors.initials: PA
authors.lastname: Lundberg
authors.forename: B A
authors.initials: BA
authors.lastname: Bengtsson
mesh_terms: D000328:Adult; D000367:Age Factors; D001794:Blood Pressure; D001827:Body Height; D002112:Calcifediol / Q000097:blood*; D053493:Cholestanetriol 26-Monooxygenase; D005260:Female; D005340:Fibrinogen / Q000032:analysis; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009749:Nutrition Surveys; D015675:Osteocalcin / Q000097:blood; D010281:Parathyroid Hormone / Q000097:blood; D013250:Steroid Hydroxylases / Q000097:blood*; D013472:Sunlight; D013548:Sweden
chemical_list: D010281:Parathyroid Hormone; D015675:Osteocalcin; D005340:Fibrinogen; D013250:Steroid Hydroxylases; C506831:CYP27A1 protein, human; D053493:Cholestanetriol 26-Monooxygenase; D002112:Calcifediol