title: The contributions of solar ultraviolet radiation exposure and other determinants to serum 25-hydroxyvitamin D concentrations in Australian adults: the AusD Study.
abstract: The Quantitative Assessment of Solar UV [ultraviolet] Exposure for Vitamin D Synthesis in Australian Adults (AusD) Study aimed to better define the relationship between sun exposure and serum 25-hydroxyvitamin D (25(OH)D) concentration. Cross-sectional data were collected between May 2009 and December 2010 from 1,002 participants aged 18-75 years in 4 Australian sites spanning 24° of latitude. Participants completed the following: 1) questionnaires on sun exposure, dietary vitamin D intake, and vitamin D supplementation; 2) 10 days of personal ultraviolet radiation dosimetry; 3) a sun exposure and physical activity diary; and 4) clinical measurements and blood collection for 25(OH)D determination. Our multiple regression model described 40% of the variance in 25(OH)D concentration; modifiable behavioral factors contributed 52% of the explained variance, and environmental and demographic or constitutional variables contributed 38% and 10%, respectively. The amount of skin exposed was the single strongest contributor to the explained variance (27%), followed by location (20%), season (17%), personal ultraviolet radiation exposure (8%), vitamin D supplementation (7%), body mass index (weight (kg)/height (m)(2)) (4%), and physical activity (4%). Modifiable behavioral factors strongly influence serum 25(OH)D concentrations in Australian adults. In addition, latitude was a strong determinant of the relative contribution of different behavioral factors.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Kimlin
authors.forename: Robyn M
authors.initials: RM
authors.lastname: Lucas
authors.forename: Simone L
authors.initials: SL
authors.lastname: Harrison
authors.forename: Ingrid
authors.initials: I
authors.lastname: van der Mei
authors.forename: Bruce K
authors.initials: BK
authors.lastname: Armstrong
authors.forename: David C
authors.initials: DC
authors.lastname: Whiteman
authors.forename: Anne
authors.initials: A
authors.lastname: Kricker
authors.forename: Madeleine
authors.initials: M
authors.lastname: Nowak
authors.forename: Alison M
authors.initials: AM
authors.lastname: Brodie
authors.forename: Jiandong
authors.initials: J
authors.lastname: Sun
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001315:Australia; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D019587:Dietary Supplements / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D015596:Nutrition Assessment; D012044:Regression Analysis; D013472:Sunlight; D011795:Surveys and Questionnaires; D013997:Time Factors; D014466:Ultraviolet Rays; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology* / Q000517:prevention & control; D055815:Young Adult
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: determinants; sunlight; ultraviolet; vitamin D