title: A Four-Year Trend in Serum 25-Hydroxyvitamin D Levels in Western Connecticut.
abstract: OBJECTIVE
  This study describes the trends in blood vitamin D levels in a regional population from 2009-2012 through a cross-sectional study design.
  
  
  METHODS
  Over a four-year period (2009-2012), serum levels of 25-hydroxyvitamin D [25(OH)D] have been measured using an automated enzyme immunoassay with a steadily increasing number of tests performed each year. A total of 54700 tests were performed during this period, with a 90% increase in annual tests ordered.
  
  
  RESULTS
  Mean and median serum levels of 25(OH) D showed statistically significant increases during this period. Those with 25(OH)D levels below 10 ng/mL represented 1.45% of the subjects in 2009 and 0.3% in 2012. The decrease in the proportion of subjects with 25(OH)D levels below 20 ng/mL and below 30 ng/mL was greatest out of all the proportioned subjects. Mean and median 25(OH)D levels increased with age in males and females.
  
  
  CONCLUSIONS
  These results likely reflect increased health awareness in Western Connecticut compared with national surveys showing a temporal decrease in 25(OH)D levels.
authors.forename: Joseph
authors.initials: J
authors.lastname: Belsky
authors.forename: Salvador
authors.initials: S
authors.lastname: Sena
authors.forename: Saad
authors.initials: S
authors.lastname: Baqai
authors.forename: Lauren C
authors.initials: LC
authors.lastname: Dilello
authors.forename: Joann R
authors.initials: JR
authors.lastname: Petrini
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D003237:Connecticut / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D