Vitamin D levels during pregnancy and associations with birth weight and body composition of the newborn: a longitudinal multiethnic population-based study

Abstract

We investigated associations between serum 25-hydroxyvitamin D (25(OH)D) in pregnancy and birth weight and other neonatal anthropometric measures. The present study was a population-based, multiethnic cohort study of 719 pregnant women (59 % ethnic minorities) in Oslo, Norway, delivering a singleton neonate at term and with birth weight measurements. In a representative sample, anthropometric measurements were taken. Maternal 25(OH)D was measured at gestational weeks 15 and 28. Women with 25(OH)D <37 nmol/l were recommended vitamin D3 supplementation. Separate linear regression analyses were performed to model the associations between 25(OH)D and each of the outcomes: birth weight, crown-heel length, head circumference, abdominal circumference, sum of skinfolds, mid-upper arm circumference and ponderal index. In early pregnancy, 51 % of the women were vitamin D deficient (25(OH)D<50 nmol/l). In univariate analyses and in models adjusting for maternal age, parity, education, prepregnancy BMI, season, gestational age and neonate sex, maternal 25(OH)D was significantly associated with birth weight, head circumference, abdominal circumference and ponderal index (P<0·05 for all), when used as a continuous variable and categorised (consistently low, consistently high, increasing and decreasing level). However, after adjusting for ethnicity, 25(OH)D was no longer associated with any of the outcomes. Sex-specific associations for abdominal circumference and sum of skinfolds were found (P for interaction<0·05). In conclusion, in a multiethnic cohort of pregnant women with high prevalence of vitamin D deficiency, we found no independent relation between maternal vitamin D levels and any of the neonatal anthropometric measures, and the strong association between ethnicity and neonatal outcomes was not affected by maternal vitamin D status.

Concentration of 25-hydroxyvitamin D from neonatal dried blood spots and the relation to gestational age, birth weight and Ponderal Index: the D-tect study

“…Multiple causes might explain the inconsistent findings, such as difference in birth period (1981-2002 v. 2010-2012), possible lifestyle changes between 1981 and 2012, sample selection (representative sample v. healthy women), 25(OH)D concentrations (27•2 (SD 18•3) v. 47•0 (SD 21•7) nmol/l) and methodological differences (DBS v. cord blood; adjustment for different confounders; residual confounding). In regard to Ponderal Index, no associations were found in the studies by Eggemoen et al and Gernand et al (8,43) . These discrepancies might be owing to different study designs, analytic methods and lack of power, but may also relate to the relative difficulty of measuring the crown-heel length of newborns.…”

“…However, contrary to our findings, as well as to those of Zhu et al and Gernand et al, Shor et al and Eggemoen et al did not find an association between maternal vitamin D and birth weight. However, in these two latter studies, analyses were limited to using linear models (8,21,42,43) . Furthermore, another Danish study (44) found a U-shaped association between cord 25(OH)D and birth weight.…”

Vitamin D status of pregnant mothers and its effect on anthropometric measures in the offspring: A preliminary study

“…There was no significant effect on growth parameters of the infant even if the mother showed vitamin D insufficiency/deficiency (Table 4). 9,10,11 . It is clear that there is lack of consensus and this conflicting evidence could be due to variations of study designs, timing of vitamin D testing during pregnancy, cut-off point of vitamin D deficiency, ethnicity and genetic variation of the study population.…”

“…Considerable number of studies have shown that there is a link between maternal calcium and vitamin D status and fetal growth 1,8 . However, some studies have failed to demonstrate a relationship between vitamin D and neonatal growth parameters 9,10,11 . Reasons for such mixed results could be variations in study design, ethnicity and laboratory methods used.…”

Variation Trend of Vitamin D Status in Wintertime Among Infants: A Cross-sectional Study

“…The vitamin D deficiency of low birth weight might be the subsequent effect of maternal vitamin D deficiency. Many studies concluded that maternal vitamin D insufficiency is independently associated with low birth weight [21][22][23]. Hence, for low birth weight infant, might be a higher dose of vitamin D supplement was effectible for vitamin D deficiency prevention, and further studies were needed to explore.…”