title: Randomized trial of fortified milk and supplements to raise 25-hydroxyvitamin D concentrations in schoolchildren in Mongolia.
abstract: BACKGROUND
  The optimal public health strategy for maintaining 25-hydroxyvitamin D [25(OH)D] concentrations in schoolchildren in Mongolia is unknown.
  
  
  OBJECTIVE
  The objective was to compare the effectiveness of different supplement and fortified milk regimens to increase 25(OH)D concentrations in Mongolian schoolchildren.
  
  
  METHODS
  Twenty-one classrooms of 579 children aged 9-11 y were randomized to interventions with an equivalent content of vitamin D(3): 1) a one-time seasonal supplement of 13,700 IU, 2) 300 IU/d from supplements, 3) 300 IU/d from fortified ultra-high-temperature pasteurized milk from the United States, 4) 300 IU/d from fortified pasteurized Mongolian milk, or 5) unfortified pasteurized Mongolian milk (control).
  
  
  RESULTS
  In January, the mean (±SD) serum 25(OH)D concentration was 8 ± 4 ng/mL (20 ± 10 nmol/L), and 98% of the children had a concentration <20 ng/mL (50 nmol/L). In March, concentrations were 8 ± 4 ng/mL after unfortified milk, 20 ± 6 ng/mL after fortified Mongolian milk, 29 ± 10 ng/mL after fortified US milk, 21 ± 6 ng/mL after daily supplements, and 12 ± 4 ng/mL after seasonal supplements (each greater than unfortified milk, P < 0.01). Seasonal supplementation was less effective than was daily supplementation (P < 0.0001). Despite consuming daily supplements or fortified milk, 41% of the children still had concentrations <20 ng/mL (50 nmol/L). Children with lower baseline 25(OH)D concentrations experienced slightly larger 25(OH)D responses to intervention than did children with higher concentrations (P = 0.002).
  
  
  CONCLUSIONS
  In this population with extremely low vitamin D concentrations, delivery of 300 IU vitamin D/d via supplements or in fortified milk improved 25(OH)D concentrations but failed to raise concentrations uniformly to >20 ng/mL (50 nmol/L). The daily low-dose intervention was superior to the seasonal larger-dose intervention. Higher doses may be needed to prevent deficiency in schoolchildren in Mongolia and at other northern latitudes. This trial is registered at clinicaltrials.gov as NCT00886379.
authors.affiliation: Connors Center for Women's Health and Gender Biology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA. jr33@partners.org
authors.forename: Janet W
authors.initials: JW
authors.lastname: Rich-Edwards
authors.forename: Davaasambuu
authors.initials: D
authors.lastname: Ganmaa
authors.forename: Ken
authors.initials: K
authors.lastname: Kleinman
authors.forename: Namjav
authors.initials: N
authors.lastname: Sumberzul
authors.forename: Michael F
authors.initials: MF
authors.lastname: Holick
authors.forename: Tserenkhuu
authors.initials: T
authors.lastname: Lkhagvasuren
authors.forename: Batbaatar
authors.initials: B
authors.lastname: Dulguun
authors.forename: Anne
authors.initials: A
authors.lastname: Burke
authors.forename: A Lindsay
authors.initials: AL
authors.lastname: Frazier
mesh_terms: D000818:Animals; D002648:Child; D019587:Dietary Supplements; D005260:Female; D005527:Food, Fortified; D006801:Humans; D008297:Male; D008892:Milk; D008986:Mongolia; D014807:Vitamin D / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D