title: Sunlight exposure or vitamin D supplementation for vitamin D-deficient non-western immigrants: a randomized clinical trial.
abstract: Vitamin D deficiency is very common in non-western immigrants. In this randomized clinical trial, vitamin D 800 IU/day or 100,000 IU/3 months were compared with advised sunlight exposure. Vitamin D supplementation was more effective than advised sunlight exposure in improving vitamin D status and lowering parathyroid hormone levels.
  
  
  BACKGROUND
  Vitamin D deficiency (25-hydroxyvitamin D [25(OH)D] < 25 nmol/l) is common among non-western immigrants. It can be treated with vitamin D supplementation or sunlight exposure.
  
  
  METHODS
  To determine whether the effect of vitamin D(3) supplementation (daily 800 IU or 100,000 IU/3 months) or sunlight exposure advice is similar with regard to serum 25(OH)D and parathyroid hormone (PTH) concentrations. Randomized clinical trial in 11 general practices in The Netherlands. Non-western immigrants, aged 18-65 years (n = 232) and serum 25(OH)D < 25 nmol/l were randomly assigned to supplementation (daily 800 IU or 100,000 IU/3 months) or advice for sunlight exposure for 6 months (March-September). Blood samples were collected at baseline, during treatment (3 months, 6 months), and at follow-up (12 months). Statistical analysis was performed with multilevel regression modelling.
  
  
  RESULTS
  The intention-to-treat analysis included 211 persons. Baseline serum 25(OH)D was 22.5 ± 11.1 nmol/l. After 6 months, mean serum 25(OH)D increased to 53 nmol/l with 800 IU/day, to 50.5 nmol/l with 100,000 IU/3 months, and to 29.1 nmol/l with advised sunlight exposure (supplementation vs sunshine p < 0.001). Serum PTH decreased significantly in all groups after 3 months, more in the supplementation groups than in the advised sunlight group (p < 0.05). There was no significant effect on physical performance and functional limitations.
  
  
  CONCLUSIONS
  Vitamin D supplementation is more effective than advised sunlight exposure for treating vitamin D deficiency in non-western immigrants.
authors.affiliation: EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: I S
authors.initials: IS
authors.lastname: Wicherts
authors.forename: A J P
authors.initials: AJ
authors.lastname: Boeke
authors.forename: I M
authors.initials: IM
authors.lastname: van der Meer
authors.forename: N M
authors.initials: NM
authors.lastname: van Schoor
authors.forename: D L
authors.initials: DL
authors.lastname: Knol
authors.forename: P
authors.initials: P
authors.lastname: Lips
mesh_terms: D000293:Adolescent; D000328:Adult; D000349:Africa / Q000208:ethnology; D000368:Aged; D001208:Asia / Q000208:ethnology; D019587:Dietary Supplements; D054242:Emigrants and Immigrants; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009048:Motor Skills; D009426:Netherlands; D010147:Pain Measurement; D010281:Parathyroid Hormone / Q000097:blood; D013020:South America / Q000208:ethnology; D013472:Sunlight; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000208:ethnology / Q000628:therapy*; D014815:Vitamins / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D010281:Parathyroid Hormone; D014815:Vitamins; D014807:Vitamin D; C104450:25-hydroxyvitamin D