title: Sun exposure and vitamin D supplementation in relation to vitamin D status of breastfeeding mothers and infants in the global exploration of human milk study.
abstract: Although vitamin D (vD) deficiency is common in breastfed infants and their mothers during pregnancy and lactation, a standardized global comparison is lacking. We studied the prevalence and risk factors for vD deficiency using a standardized protocol in a cohort of breastfeeding mother-infant pairs, enrolled in the Global Exploration of Human Milk Study, designed to examine longitudinally the effect of environment, diet and culture. Mothers planned to provide breast milk for at least three months post-partum and were enrolled at four weeks postpartum in Shanghai, China (n=112), Cincinnati, Ohio (n=119), and Mexico City, Mexico (n=113). Maternal serum 25(OH)D was measured by radioimmunoassay (<50 nmol/L was categorized as deficient). Serum 25(OH)D was measured in a subset of infants (35 Shanghai, 47 Cincinnati and 45 Mexico City) seen at 26 weeks of age during fall and winter seasons. Data collected prospectively included vD supplementation, season and sun index (sun exposure×body surface area exposed while outdoors). Differences and factors associated with vD deficiency were evaluated using appropriate statistical analysis. vD deficiency in order of magnitude was identified in 62%, 52% and 17% of Mexican, Shanghai and Cincinnati mothers, respectively (p<0.001). In regression analysis, vD supplementation (p<0.01), obesity (p=0.03), season (p=0.001) and sites (p<0.001) predicted maternal vD status. vD deficiency in order of magnitude was found in 62%, 28%, and 6% of Mexican, Cincinnati and Shanghai infants, respectively (p<0.001). Season (p=0.022), adding formula feeding (p<0.001) and a higher sun index (p=0.085) predicted higher infant vD status. vD deficiency appears to be a global problem in mothers and infants, though the prevalence in diverse populations may depend upon sun exposure behaviors and vD supplementation. Greater attention to maternal and infant vD status starting during pregnancy is warranted worldwide.
authors: Global Health Center, Perinatal Institute and Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA. adekunle.dawodu@cchmc.org.
authors: Adekunle
authors: A
authors: Dawodu
authors: Global Health Center, Perinatal Institute and Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA. barbara.davidson@cchmc.org.
authors: Barbara
authors: B
authors: Davidson
authors: Global Health Center, Perinatal Institute and Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA. jessica.woo@cchmc.org.
authors: Jessica G
authors: JG
authors: Woo
authors: Children's Hospital of Fudan University, 399 Wanyuan Road, Shanghai 20102, China. ympeng@fudan.edu.cn.
authors: Yong-Mei
authors: YM
authors: Peng
authors: National Institute of Medical Sciences and Nutrition, Vasco de Quiroga No. 15, Tlalpan, Mexico City 14000, Mexico. mlga08@gmail.com.
authors: Guillermo M
authors: GM
authors: Ruiz-Palacios
authors: National Institute of Medical Sciences and Nutrition, Vasco de Quiroga No. 15, Tlalpan, Mexico City 14000, Mexico. mlga08@gmail.com.
authors: Maria
authors: M
authors: de Lourdes Guerrero
authors: Global Health Center, Perinatal Institute and Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA. ardythe.morrow@cchmc.org.
authors: Ardythe L
authors: AL
authors: Morrow
mesh_terms: D000328:Adult; D001942:Breast Feeding; D002112:Calcifediol / Q000097:blood; D002681:China / Q000453:epidemiology; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D007223:Infant; D041943:Infant Formula / Q000008:administration & dosage; D007774:Lactation / Q000097:blood; D008137:Longitudinal Studies; D008297:Male; D008800:Mexico / Q000453:epidemiology; D009035:Mothers; D049590:Postpartum Period / Q000097:blood; D011247:Pregnancy; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D012621:Seasons; D013472:Sunlight; D014481:United States / Q000453:epidemiology; D014807:Vitamin D / Q000008:administration & dosage* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000178:diet therapy* / Q000453:epidemiology; D055815:Young Adult
chemical_list: D014807:Vitamin D; D002112:Calcifediol