RESUMO
To prevent rickets, the Health Canada and the American Academy of Pediatrics recommend that breastfed infants receive a daily vitamin D supplement of 10 µg d(-1) . Compliance with this recommendation is variable and its effect on infant vitamin D status is unclear. We measured serum 25-hydroxyvitamin D (25OHD) in Asian immigrant (n=28) and White (n=37) mothers and their infants aged 2-4 months living in Vancouver (49°N). Mothers completed health and demographic questionnaires. All subjects were term infants who were primarily breastfed. Analysis of variance, χ(2) , multiple regression and logistic regression analysis were performed as appropriate. Mean 25OHD of the infants was 31 (95% confidence interval 28-34) ng mL(-1) . Only two infants had a 25OHD concentration indicative of deficiency, <10 ng mL(-1) . Of the infants, 14% (n=9) and 49% (n=32) were vitamin D insufficient based on two commonly used cut-offs of 20 and 30 ng mL(-1) , respectively. Fifty-eight (89%) infants had been given a vitamin D supplement. Mean 25OHD was 9.4 ng mL(-1) higher in infants consuming ≥10 µg d(-1) of vitamin D from supplements vs. those consuming less (P=0.003). Mother's 25OHD, season, skin colour or ethnicity (Asian vs. White) did not influence infant 25OHD. The infants in our study, most of whom received vitamin D supplements, were generally protected against low 25OHD. The study was limited by sample size and the nature of the cross-sectional study design.
