title: Assessing Serum Concentrations of 25-Hydroxy-Vitamin D in North-Western Italy.
abstract: OBJECTIVE
  Backgound: Most of the published studies on vitamin D levels in Italy have been performed in specific age- or disease- subgroups. Few data are available on the status of vitamin D in the adult general population.
  
  
  OBJECTIVE
  We report on vitamin D levels of a large sample of adults from North-Western Italy. Association with age, sex, and season is also evaluated.
  
  
  METHODS
  13,110 cases (24% men, 76% women; median age 67 [interquartile range, IQR, 56-77] years old) were collected in the North-Eastern of Piedmont (Italy).
  
  
  METHODS
  25-OH-vitamin D levels were measured by chemiluminescent immunoassay.
  
  
  RESULTS
  Median total vitamin D level was 19.9 ng/ml (IQR 11.2-28.8 ng/ml) with up to 3,592 (27.4%) and 10,185 (77.7%) subjects respectively below 12 and 30 ng/ml. Vitamin D levels were significantly higher in women than in men (20.5 vs 18.1 ng/ml; p<0.001), in summer than in winter (21.4 vs 18.5 ng/ml; p<0.001), and in individuals aged ≤45years or 46-64 years than in those older than 65 years (20.3 and 21.3 vs 18.8 ng/ml). The lowest mean vitamin D levels were reported during the winter season by men aged ≥65 years (14.7 ng/ml) and 46-64 years (16.8 ng/ml). Multivariate analysis confirmed that age (p<0.001), sex (p=0.002), season (p<0.001) and their interaction (p=0.03) were independently associated to vitamin D concentrations.
  
  
  CONCLUSIONS
  This study clearly shows that the majority of adult Italian population, living in a sunny and highly urbanized area of North-Western Italy, have an important deficiency in vitamin D. However, these data must be interpreted with caution if considering the lack of standardization of vitamin D assays.
authors.affiliation: Matteo Vidali, PhD, MD, Department of Health Sciences, University "Amedeo Avogadro" of Eastern Piedmont, Via Solaroli 17, 28100 Novara (Italy) and Clinical Chemistry Unit, Maggiore della Carità Hospital, Corso Mazzini 18, 28100 Novara (Italy), Phone: +39 0321 660650 (Univ); +39 0321 3733246 (Hosp), Fax: +39 0321 620421 (Univ); +39 0321 3733516 (Hosp), Email: vidali@med.unipmn.it.
authors.forename: M
authors.initials: M
authors.lastname: Basile
authors.forename: L
authors.initials: L
authors.lastname: Ciardi
authors.forename: I
authors.initials: I
authors.lastname: Crespi
authors.forename: E
authors.initials: E
authors.lastname: Saliva
authors.forename: G
authors.initials: G
authors.lastname: Bellomo
authors.forename: M
authors.initials: M
authors.lastname: Vidali