Abstract :
Keywords Infant; Vitamin D supplementation; Season; Gross motor development Highlights * In North America, vitamin D supplementation (400 IU/d) is recommended for infants. * This study tested gross motor development at 36 months of age. * Gross motor quotient was not affected by vitamin D dose (400--1200 IU/d) in infancy. * A vitamin D dose of 400 IU/d in infancy adequately supports gross motor development Abstract Background Vitamin D status during pregnancy, early childhood and season-at-birth are implicated in gross motor development (GMD). Aim To test whether vitamin D intake in infancy and season-at-birth affect GMD in early childhood. Study design 3-year follow up study of a single-center trial. Subjects Healthy infants (n = 116) were allocated to 400 (standard-of-care), 800 or 1200 IU/day of vitamin D3 supplementation from 1 to 12 months; n = 70 returned for follow-up at 3-years. Outcome measures The main outcome was GMD using the Peabody Developmental Motor Scales-2 which includes gross motor quotient (GMQ) and stationary, locomotion and object manipulation subtests. Results GMQ scores were normal ([greater than or equal to]85) in 94 %. An interaction between dosage group and season-at-birth (p = 0.01) was observed for GMQ and stationary standardized score; among winter/spring born children, the 1200 IU/d scored higher vs. 400 and 800 IU/d groups. Object manipulation standardized score was higher (p = 0.04) in children in the 1200 vs. 400 IU/d group, without interaction with season-at-birth. Conclusions GMD in young children who received 400 IU/d of supplemental vitamin D in infancy is not influenced by season-at-birth. This dose of vitamin D of 400 IU/d as recommended in North America adequately supports GMD. The modest enhancement in GMD with 1200 IU/d in winter/spring born children requires further study. Abbreviations GMD, gross motor development; GMQ, gross motor quotient; PDMS-2, Peabody Developmental Motor Scales-2; 25OHD, 25-hydroxyvitamin D Author Affiliation: (a) School of Human Nutrition, McGill University, Ste Anne de Bellevue, QC, Canada (b) School of Physical and Occupational Therapy, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada (c) Research Institute of the McGill University Health Centre, Montreal, QC, Canada (d) Department of Pediatrics, Faculty of Medicine, McGill University, Montreal, QC, Canada (e) Nutrition Research Division, Bureau of Nutritional Sciences, Health Products and Food Branch, Health Canada, Ottawa, ON, Canada (f) Department of Kinesiology and Physical Education, Wilfrid Laurier University, Waterloo, ON, Canada (g) Nutritional Sciences, University of Georgia, Athens, GA, United States of America (h) Department of Pediatrics and Child Health, Children's Hospital Research Institute, University of Manitoba, Winnipeg, MB, Canada * Corresponding author at: Nutrition Research Division, Health Products and Food Branch, Health Canada, 251 Sir Frederick Banting Driveway, Room E338, Ottawa, K1A 0K9, Ontario, Canada. Article History: Received 7 March 2022; Accepted 16 June 2022 Byline: Hope A. Weiler [hope.weiler@hc-sc.gc.ca] (a,e,*), Tom J. Hazell (a,f), Annette Majnemer (b,c), Catherine A. Vanstone (a), Sina Gallo (a,g), Celia J. Rodd (a,d,h)