title: High-Dose Monthly Maternal Cholecalciferol Supplementation during Breastfeeding Affects Maternal and Infant Vitamin D Status at 5 Months Postpartum: A Randomized Controlled Trial.
abstract: BACKGROUND
  Many countries recommend daily infant vitamin D supplementation during breastfeeding, but compliance is often poor. A monthly, high-dose maternal regimen may offer an alternative strategy, but its efficacy is unknown.
  
  
  OBJECTIVE
  The objective of the study was to determine the effect of 2 different monthly maternal doses of cholecalciferol on maternal and infant 25-hydroxyvitamin D [25(OH)D] status during the first 5 mo of breastfeeding.
  
  
  METHODS
  With the use of a randomized, double-blind, placebo-controlled design, women who were planning to exclusively breastfeed for 6 mo (n = 90; mean age: 32.1 y; 71% exclusively breastfeeding at week 20) were randomly assigned to receive either cholecalciferol (50,000 or 100,000 IU) or a placebo monthly from week 4 to week 20 postpartum. The treatment effects relative to placebo were estimated as changes in maternal and infant serum 25(OH)D from baseline to week 20 postpartum by using a linear fixed-effects regression model. Additional secondary analyses, adjusted for potential confounders such as season of birth, vitamin D-fortified formula intake, and infant or maternal skin color, were also conducted.
  
  
  RESULTS
  After 16 wk of supplementation, changes in maternal serum 25(OH)D were significantly higher in the 50,000-IU/mo (12.8 nmol/L; 95% CI: 0.4, 25.2 nmol/L) and 100,000-IU/mo (21.5 nmol/L; 95% CI: 9.2, 33.8 nmol/L) groups than in the placebo group (P = 0.43 and P < 0.001, respectively). For infants, the unadjusted mean changes in serum 25(OH)D were 4.5 nmol/L (95% CI: -16.2, 25.0 nmol/L) for the 50,000-IU/mo group and 15.8 nmol/L (95% CI: -4.7, 36.4 nmol/L) for the 100,000-IU/mo group, but the changes did not differ from the placebo reference group. However, after adjustment for season of birth, vitamin D-fortified formula intake, and infant skin color, the mean change effect size for the 100,000-IU/mo group was 19.1 nmol/L (95% CI: 2.5, 35.6 nmol/L; P = 0.025) higher than that in the placebo group.
  
  
  CONCLUSIONS
  Maternal cholecalciferol supplementation at a dose of 100,000 IU/mo during the first 5 mo of breastfeeding potentially benefits infant vitamin D status. Further studies are required to determine optimum dose and dosing frequency. This trial was registered at www.anzctr.org.au as ACTRN12611000108910.
authors: Departments of Women's and Children's Health and Pediatric Endocrinology, Southern District Health Board, Dunedin, New Zealand ben.wheeler@otago.ac.nz.
authors: Benjamin J
authors: http://orcid.org/0000-0003-3348-5238
authors: BJ
authors: Wheeler
authors: Departments of Women's and Children's Health and.
authors: Barry J
authors: BJ
authors: Taylor
authors: Preventive and Social Medicine, Dunedin School of Medicine, and.
authors: Peter
authors: P
authors: Herbison
authors: Departments of Women's and Children's Health and.
authors: Jillian J
authors: JJ
authors: Haszard
authors: Departments of Women's and Children's Health and.
authors: Adel
authors: A
authors: Mikhail
authors: Departments of Women's and Children's Health and.
authors: Shirley
authors: S
authors: Jones
authors: Department of Human Nutrition, University of Otago, Dunedin, New Zealand; and.
authors: Michelle J
authors: MJ
authors: Harper
authors: Department of Human Nutrition, University of Otago, Dunedin, New Zealand; and.
authors: Lisa A
authors: LA
authors: Houghton
mesh_terms: D000328:Adult; D001942:Breast Feeding; D002762:Cholecalciferol / Q000008:administration & dosage* / Q000097:blood; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D006801:Humans; D007223:Infant; D007227:Infant Nutritional Physiological Phenomena; D007774:Lactation; D039382:Maternal Nutritional Physiological Phenomena; D049590:Postpartum Period / Q000097:blood; D016896:Treatment Outcome; D014807:Vitamin D / Q000097:blood*
chemical_list: D014807:Vitamin D; D002762:Cholecalciferol
keywords: 25-hydroxyvitamin D; breastfeeding infant; cholecalciferol; lactation; vitamin D