Birth weight, length, head circumference and Maternal 25 Hydroxyvitamin D (25OHD) concentration in mother‐infant pairs living in Vancouver, British Columbia, Canada

Abstract

Results of studies examining associations between maternal 25OHD and birth anthropometric measures have been equivocal. Here we examine the association between maternal 25OHD (20–35 wks) and each of birth weight, birth length, and head circumference in 306 mother‐infant pairs living in Vancouver (49°N). Mean (SD) maternal 25OHD was 66 (23) nmol/L. 25% and 65% had 25OHD levels <50 and <75 nmol/L, respectively, two commonly‐used cutoffs for vitamin D insufficiency. In multivariate analyses controlling for potential confounders (i.e. maternal height, season, and ethnicity) there was no association [β (95 % CI); P] between maternal 25OHD and each of birth weight [0.2 kg (−2.5, 3.0); P=0.83], birth length [0.08 cm (−0.007, 0.023); P=0.98], or head circumference [0.00 cm (−0.009, 0.008); P=0.98]. Likewise, having a maternal 25OHD < 50 or <75 nmol/L was not associated with birth weight, birth length, or head circumference in logistic regressions. Despite a high prevalence of vitamin D insufficiency, maternal 25OHD was not associated with birth anthropometric measures in this sample. (Supported by the Canadian Vitamin Class Action settlement)