title: Vitamin D deficiency and supplementation in pregnancy in a multiethnic population-based cohort.
abstract: BACKGROUND
  To investigate ethnic differences in vitamin D levels during pregnancy, assess risk factors for vitamin D deficiency and explore the effect of vitamin D supplementation in women with deficiency in early pregnancy.
  
  
  METHODS
  This is a population-based, multiethnic cohort study of pregnant women attending Child Health Clinics for antenatal care in Oslo, Norway. Serum-25-hydroxyvitamin D [25(OH)D] was measured in 748 pregnant women (59% ethnic minorities) at gestational weeks (GW) 15 (SD:3.6) and 28 (1.4). Women with 25(OH)D <37 nmol/L at GW 15 were for ethical reasons recommended vitamin D3 supplementation. Main outcome measure was 25(OH)D, and linear regression models were performed.
  
  
  RESULTS
  Severe deficiency (25(OH)D <25 nmol/L) was found at GW 15 in 45% of women from South Asia, 40% from the Middle East and 26% from Sub-Saharan Africa, compared to 2.5% in women from East Asia and 1.3% of women from Western Europe. Women from South Asia, the Middle East and Sub-Saharan Africa had mean values that were -28 (95 % CI:-33, -23), -24 (-29, -18) and -20 (-27, -13) nmol/L lower than in Western women, respectively. Ethnicity, education, season and intake of vitamin D were independently associated with 25(OH)D. At GW 28, the mean 25(OH)D had increased from 23 (SD:7.8) to 47 (27) nmol/L (p < 0.01) in women who were recommended vitamin D supplementation, with small or no change in women with sufficient vitamin D levels at baseline.
  
  
  CONCLUSIONS
  Vitamin D deficiency was prevalent among South Asian, Middle Eastern and African women. The serum levels of 25(OH)D increased significantly from GW 15 to 28 in vitamin D deficient women who received a recommendation for supplementation. This recommendation of vitamin D supplementation increased vitamin D levels in deficient women.
authors.affiliation: Department of General Practice, Institute of Health and Society, University of Oslo, Postboks 1130 Blindern, N-0318, Oslo, Norway. a.r.eggemoen@medisin.uio.no.
authors.forename: Åse R
authors.initials: ÅR
authors.lastname: Eggemoen
authors.affiliation: Oslo Center for Biostatistics and Epidemiology, Oslo University Hospital, Oslo, Norway.
authors.forename: Ragnhild S
authors.initials: RS
authors.lastname: Falk
authors.affiliation: Department of General Practice, Institute of Health and Society, University of Oslo, Postboks 1130 Blindern, N-0318, Oslo, Norway.
authors.forename: Kirsten V
authors.initials: KV
authors.lastname: Knutsen
authors.affiliation: Department of General Practice, Institute of Health and Society, University of Oslo, Postboks 1130 Blindern, N-0318, Oslo, Norway.
authors.forename: Per
authors.initials: P
authors.lastname: Lagerløv
authors.affiliation: Department of Child and Adolescence Medicine, Akershus University Hospital, Lørenskog, Norway.
authors.forename: Line
authors.initials: L
authors.lastname: Sletner
authors.affiliation: Department of Endocrinology, Morbid Obesity and Preventive Medicine, Oslo University Hospital, Oslo, Norway.|Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
authors.forename: Kåre I
authors.initials: KI
authors.lastname: Birkeland
authors.affiliation: Department of General Practice, Institute of Health and Society, University of Oslo, Postboks 1130 Blindern, N-0318, Oslo, Norway.
authors.forename: Anne K
authors.initials: AK
authors.lastname: Jenum
mesh_terms: D000328:Adult; D044466:Asian People / Q000706:statistics & numerical data; D044383:Black People / Q000706:statistics & numerical data; D002762:Cholecalciferol / Q000627:therapeutic use; D015331:Cohort Studies; D019587:Dietary Supplements / Q000706:statistics & numerical data*; D005006:Ethnicity / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008875:Middle Aged; D008877:Middle East / Q000208:ethnology; D009664:Norway / Q000453:epidemiology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000188:drug therapy / Q000208:ethnology*; D011262:Pregnancy Trimester, Second / Q000097:blood / Q000208:ethnology; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000188:drug therapy / Q000208:ethnology*; D014815:Vitamins / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D014815:Vitamins; D014807:Vitamin D; D002762:Cholecalciferol; C104450:25-hydroxyvitamin D