title: Vitamin D activity of breast milk in women randomly assigned to vitamin D3 supplementation during pregnancy.
abstract: BACKGROUND
  Human milk is typically low in vitamin D activity (VDA). Whether the vitamin D content of breast milk at birth can be increased by supplementing the mother during pregnancy has not been reported to the best of our knowledge.
  
  
  OBJECTIVE
  We examined the effect of vitamin D supplementation during pregnancy on breast-milk VDA in the first 2 mo of lactation.
  
  
  METHODS
  Breast-milk samples were obtained from women who were enrolled in a randomized, double-blinded, placebo-controlled trial of vitamin D supplementation during pregnancy. Pregnant women were enrolled at 27 wk of gestation and randomly assigned to the following 3 groups: a placebo group, a group who received one dosage of daily oral vitamin D3 (1000 IU), or a group who received 2 dosages of daily oral vitamin D3 (2000 IU). Serum 25-hydroxyvitamin D [25(OH)D] was measured at enrollment, at 36 wk of gestation, and in cord blood at birth. Study participants who were breastfeeding were invited to provide breast-milk samples for VDA measurement [concentration of vitamin D2, vitamin D3, 25(OH)D2, and 25(OH)D3] at 2 wk and 2 mo postpartum. A linear mixed model was used to compare breast-milk VDA between the 3 study groups.
  
  
  RESULTS
  A total of 75 women provided breast-milk samples (44 women provided breast-milk samples at both 2 wk and 2 mo postpartum). The mean (95% CI) VDA at age 2 wk was 52 IU/L (12, 217 IU/L) in the placebo group, 51 IU/L (17, 151 IU/L) in the 1000-IU group, and 74 IU/L (25, 221 IU/L) in the 2000-IU group; and at age 2 mo, the mean (95% CI) VDA was 45 IU/L (16, 124 IU/L), 43 IU/L (18, 103 IU/L), and 58 IU/L (15, 224 IU/L), respectively. There was no significant interaction in VDA between the sample-collection time and treatment (P = 0.61), but there was a difference between lower- and higher-dosage treatment groups (P = 0.04).
  
  
  CONCLUSIONS
  Maternal vitamin D supplementation during pregnancy of 2000 IU/d (compared with 1000 IU/d and with a placebo) results in a higher VDA of breast milk ≥2 mo postpartum. This trial was registered at the Australian New Zealand Clinical Trials Registry as ACTRN12610000483055.
authors.affiliation: Discipline of Nutrition and Dietetics, c.wall@auckland.ac.nz.
authors.forename: Clare R
authors.initials: CR
authors.lastname: Wall
authors.affiliation: School of Population Health.
authors.forename: Alistair W
authors.initials: AW
authors.lastname: Stewart
authors.affiliation: Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA;
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Camargo
authors.affiliation: School of Population Health.
authors.forename: Robert
authors.initials: R
authors.lastname: Scragg
authors.affiliation: Department of Pediatrics: Child & Youth Health, and.
authors.forename: Edwin A
authors.initials: EA
authors.lastname: Mitchell
authors.affiliation: Obstetrics & Gynecology, University of Auckland, Auckland, New Zealand;
authors.forename: Alec
authors.initials: A
authors.lastname: Ekeroma
authors.affiliation: Medicine, University of Otago, Wellington, New Zealand;
authors.forename: Julian
authors.initials: J
authors.lastname: Crane
authors.affiliation: Department of Pediatrics: Child & Youth Health, and.
authors.forename: Tania
authors.initials: T
authors.lastname: Milne
authors.affiliation: Department of Pediatrics: Child & Youth Health, and.
authors.forename: Judy
authors.initials: J
authors.lastname: Rowden
authors.affiliation: Heartland Assays LLC, Ames, IA; and.
authors.forename: Ronald
authors.initials: R
authors.lastname: Horst
authors.affiliation: Department of Pediatrics: Child & Youth Health, and Starship Children's Hospital, Auckland District Health Board, Auckland, New Zealand.
authors.forename: Cameron C
authors.initials: CC
authors.lastname: Grant
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000032:analysis / Q000097:blood / Q000378:metabolism; D000328:Adult; D002112:Calcifediol / Q000097:blood / Q000378:metabolism; D002762:Cholecalciferol / Q000032:analysis / Q000378:metabolism / Q000627:therapeutic use*; D019587:Dietary Supplements; D004311:Double-Blind Method; D004872:Ergocalciferols / Q000032:analysis / Q000378:metabolism; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D006801:Humans; D007231:Infant, Newborn; D007774:Lactation; D008297:Male; D039382:Maternal Nutritional Physiological Phenomena; D008431:Maternal-Fetal Exchange; D008895:Milk, Human / Q000737:chemistry* / Q000378:metabolism; D009520:New Zealand; D011247:Pregnancy; D011295:Prenatal Care; D014807:Vitamin D / Q000032:analysis* / Q000378:metabolism; D014808:Vitamin D Deficiency / Q000097:blood / Q000378:metabolism / Q000517:prevention & control*; D055815:Young Adult
chemical_list: D004872:Ergocalciferols; D014807:Vitamin D; D002762:Cholecalciferol; D015652:25-Hydroxyvitamin D 2; D002112:Calcifediol
keywords: 25-hydroxyvitamin D; breast milk; infant feeding; pregnancy; supplementation; vitamin D