title: Association of 25-hydroxyvitamin D3)levels in adult New Zealanders with ethnicity, skin color and self-reported skin sensitivity to sun exposure.
abstract: The study aim was to determine the contribution of ethnicity, objectively measured skin color and skin reaction-to-sun exposure to variations in 25-hydroxyvitamin D(3) [25(OH)D(3) ]. A multiethnic sample (European, Maori, Pacific and Asian) of 503 adult volunteers aged 18-85 years, recruited from Auckland and Dunedin in New Zealand, answered a questionnaire on sun exposure and self-defined ethnicity. Skin color was measured using a spectrophotometer and the Individual Typology Angle (ITA) calculated. A blood sample was collected 4 weeks later to measure 25(OH)D(3). 25(OH)D(3) was associated with ethnicity, but not self-reported skin reaction-to-sun exposure. Amongst the ethnic groups, Asians had the lowest mean 25(OH)D level (37.0 nmol L(-1)) and Europeans with lighter colored skin had the highest (57.9 nmol L(-1)). An association also was seen between 25(OH)D(3) and skin color, with an increase of 2-3 nmol L(-1) per 10° increase in ITA value, indicating higher 25(OH)D(3) with lighter skin color; but much of this association disappeared after adjusting for ethnicity. In contrast, ethnicity remained associated with 25(OH)D(3) after adjusting for ITA skin color and skin reaction-to-sun exposure. These results indicate that self-defined ethnicity was a major determinant of variations in serum 25(OH)D(3), while objective measures of skin color explained relatively little additional variation.
authors.affiliation: Faculty of Health Sciences, University of Linkoping, Linkoping, Sweden.
authors.forename: Sofia
authors.initials: S
authors.lastname: Nessvi
authors.forename: Lisa
authors.initials: L
authors.lastname: Johansson
authors.forename: Jan
authors.initials: J
authors.lastname: Jopson
authors.forename: Alistair
authors.initials: A
authors.lastname: Stewart
authors.forename: Anthony
authors.initials: A
authors.lastname: Reeder
authors.forename: Richard
authors.initials: R
authors.lastname: McKenzie
authors.forename: Robert K
authors.initials: RK
authors.lastname: Scragg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000208:ethnology; D002112:Calcifediol / Q000097:blood*; D003116:Color; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009520:New Zealand / Q000453:epidemiology; D012621:Seasons; D012867:Skin / Q000378:metabolism / Q000528:radiation effects; D012880:Skin Pigmentation / Q000528:radiation effects; D013472:Sunlight; D011795:Surveys and Questionnaires; D014466:Ultraviolet Rays; D014808:Vitamin D Deficiency / Q000097:blood / Q000208:ethnology / Q000503:physiopathology; D044465:White People / Q000208:ethnology
chemical_list: D002112:Calcifediol