title: Lifestyle factors including less cutaneous sun exposure contribute to starkly lower vitamin D levels in U.K. South Asians compared with the white population.
abstract: BACKGROUND
  Long-standing concerns over the vitamin D status of South Asian adults in the U.K. require studies using statistically valid sample sizes to measure annual variation and contributory lifestyle factors.
  
  
  OBJECTIVE
  To measure annual variation in the vitamin D status of U.K. South Asians, to determine the associated lifestyle influences, and to compare these with a similar study of white adults.
  
  
  METHODS
  A single-centre, prospective cohort study measuring circulating 25-hydroxyvitamin D [25(OH)D], sunlight exposure levels and lifestyle factors for 1 year in 125 ambulant South Asian adults with sun-reactive skin type V, aged 20-60 years, in Greater Manchester, U.K. (53·5°N).
  
  
  RESULTS
  The 25(OH)D levels of South Asians were alarmingly low. In summer, their median 25(OH)D level was 9·0 ng mL(-1) , [interquartile range (IQR) 6·7-13·1], falling to 5·8 ng mL(-1) (IQR 4·0-8·1) in winter. This compared with values in the white population of 26·2 ng mL(-1) (IQR 19·9-31·5) in summer and 18·9 ng mL(-1) IQR (11·6-23·7) in winter. Median daily dietary vitamin D was lower in South Asians (1·32 μg vs. 3·26 μg for white subjects) and was compounded by low supplement use. Despite similar times spent outdoors, ultraviolet (UV) dosimeters recorded lower personal UV exposure among South Asians, indicating sun avoidance when outside, while sun exposure diaries recorded lower amounts of skin surface exposure.
  
  
  CONCLUSIONS
  The majority of South Asians never reached sufficiency in vitamin D status. Lifestyle differences, with lower oral intake, sun exposure and rates of cutaneous production due to darker skin, indicate that standard advice on obtaining sufficient vitamin D needs modification for the South Asian community in the U.K.
authors.affiliation: School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Manchester, U.K.
authors.forename: R
authors.initials: R
authors.lastname: Kift
authors.forename: J L
authors.initials: JL
authors.lastname: Berry
authors.forename: A
authors.initials: A
authors.lastname: Vail
authors.forename: M T
authors.initials: MT
authors.lastname: Durkin
authors.forename: L E
authors.initials: LE
authors.lastname: Rhodes
authors.forename: A R
authors.initials: AR
authors.lastname: Webb
mesh_terms: D000328:Adult; D000368:Aged; D001459:Bangladesh / Q000208:ethnology; D016022:Case-Control Studies; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D008019:Life Style / Q000208:ethnology*; D008297:Male; D008875:Middle Aged; D010154:Pakistan / Q000208:ethnology; D011446:Prospective Studies; D012621:Seasons; D012867:Skin / Q000528:radiation effects; D012880:Skin Pigmentation / Q000502:physiology; D013472:Sunlight; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000208:ethnology / Q000209:etiology*; D055815:Young Adult
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D