Plasma 25-hydroxyvitamin D, more so than its epimer, has a linear relationship to leaner body composition across infancy in healthy term infants

• Published in: Applied physiology, nutrition, and metabolism nutrition, and metabolism, 2014-10, Vol.39 (10), p.1137-1143
• Main Authors: Hazell, Tom J, Gallo, Sina, Berzina, Ilze, Vanstone, Catherine A, Rodd, Celia, Weiler, Hope A
• Format: Article
• Language: English
• Subjects: Alfacalcidol; Babies; Body Composition; Breast feeding; C-3 alpha epimer of 25-hydroxyvitamin D; Calcifediol; Calcitriol - blood; Chromatography; composition corporelle; Female; Health aspects; Humans; infancy; Infant; Infants; Male; Mass spectrometry; Muscles; Musculoskeletal system; Physiological aspects; première enfance; Proteins; Thinness - blood; Vitamin D; Vitamin D - analogs & derivatives; Vitamin D - blood; épimère alpha C-3 de la 25-hydroxyvitamine D
• ISSN: 1715-5312; 1715-5320
• DOI: 10.1139/apnm-2013-0586

Vitamin D status positively associates with skeletal muscle mass and function in adolescents. The C-3 alpha epimer of 25-hydroxyvitamin D 3 (3-epi-25(OH)D 3 ) is high in infants, yet the potential impacts of 25-hydroxyvitamin D 3 (25(OH)D 3 ) and 3-epi-25(OH)D 3 on skeletal muscle development are largely unexplored. The objective of this study was (i) to explore how the concentrations of 25(OH)D 3 and 3-epi-25(OH)D 3 track with body composition (lean mass (LM) and fat mass (FM)) and (ii) to determine the association between 25(OH)D 3 and 3-epi-25(OH)D 3 in infancy. Healthy breastfed infants (n = 132) were followed from 1 to 12 months of age as part of a vitamin D dose–response study (NCT00381914). Anthropometry and diet were assessed. Body composition was measured with dual-energy X-ray absorptiometry. Plasma 25(OH)D 3 and 3-epi-25(OH)D 3 concentrations were evaluated using liquid chromatography tandem mass spectrometry. Plasma 25(OH)D 3 and 3-epi-25(OH)D 3 increased from 1 to 3 months of age and decreased thereafter (p < 0.05). Infants with 25(OH)D 3 concentrations above 75 nmol/L did not have a higher LM (g or %; p > 0.273) than those below this cutoff. LM was not associated with 25(OH)D 3 , whereas LM% was positively associated with 25(OH)D 3 (β = 0.03; CI: 0.01 to 0.06; p = 0.006), while accounting for sex, weight-for-age Z-score, protein and fat intake, and age. For FM, the variables accounting for a significant amount of the variation were plasma 25(OH)D 3 concentration (β = −2.38; CI: −4.35, −0.41; p = 0.019), weight-for-age Z-score, protein and fat intake, and time. In healthy infants, higher vitamin D status associates with leaner body composition, though the effect is smaller in magnitude relative to growth.