title: New perspectives on vitamin D sources in Germany based on a novel mathematical bottom-up model of 25(OH)D serum concentrations.
abstract: OBJECTIVE
  Up-to-date knowledge about vitamin D supply and serum concentration in Germany is not sufficient. Our purpose was to compare a novel holistic bottom-up modeling of 25(OH)D concentrations with vitamin D sources such as sunlight, food and supplements for all federal states taking seasonal and geographical variations into account. The second purpose was to update and detail vitamin D supply through food in Germany.
  
  
  METHODS
  To confirm the model of 25(OH)D concentrations, we used the population (1,763 men and 2,267 women, 18-79 years) participated in the representative German National Health Interview and Examination Survey 1998 and the integrated German Nutrition Survey.
  
  
  RESULTS
  The maximum model value is 67.5 nmol/L in July and minimum model value is 29.3 nmol/L in January, while the average model value is 45.0 nmol/L. Men have a mean daily intake of 137 IU (3.42 μg) and women of 112 IU (2.79 μg). Correlation between model and actual data is 0.77 (p = 0.003).
  
  
  CONCLUSIONS
  A comparison of the model data with population-based values showed good agreement. None of the vitamin D sources can provide the German population with enough vitamin D.
authors.affiliation: Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Brown
authors.forename: Anita
authors.initials: A
authors.lastname: Ignatius
authors.forename: Michael
authors.initials: M
authors.lastname: Amling
authors.forename: Florian
authors.initials: F
authors.lastname: Barvencik
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019587:Dietary Supplements; D005260:Female; D005858:Germany; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009749:Nutrition Surveys; D015203:Reproducibility of Results; D012984:Software; D013472:Sunlight; D014807:Vitamin D / Q000008:administration & dosage* / Q000097:blood*; D044465:White People; D055815:Young Adult
chemical_list: D014807:Vitamin D