Objectives To estimate the effects of vitamin D supplementation during pregnancy on 11 maternal and 27 neonatal/infant outcomes; to determine frequencies at which trial outcome data were missing, unreported, or inconsistently reported; and to project the potential contributions of registered ongoing or planned trials. Design Systematic review and meta-analysis of randomised controlled trials; systematic review of registered but unpublished trials. Data sources Medline, Embase, PubMed, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials from inception to September 2017; manual searches of reference lists of systematic reviews identified in the electronic search; and online trial registries for unpublished, ongoing, or planned trials. Eligibility criteria for study selection Trials of prenatal vitamin D supplementation with randomised allocation and control groups administered placebo, no vitamin D, or vitamin D ≤600 IU/day (or its equivalent), and published in a peer reviewed journal. Results 43 trials (8406 participants) were eligible for meta-analyses. Median sample size was 133 participants. Vitamin D increased maternal/cord serum concentration of 25-hydroxyvitamin D, but the dose-response effect was weak. Maternal clinical outcomes were rarely ascertained or reported, but available data did not provide evidence of benefits. Overall, vitamin D increased mean birth weight of 58.33 g (95% confidence interval 18.88 g to 97.78 g; 37 comparisons) and reduced the risk of small for gestational age births (risk ratio 0.60, 95% confidence interval 0.40 to 0.90; seven comparisons), but findings were not robust in sensitivity and subgroup analyses. There was no effect on preterm birth (1.0, 0.77 to 1.30; 15 comparisons). There was strong evidence that prenatal vitamin D reduced the risk of offspring wheeze by age 3 years (0.81, 0.67 to 0.98; two comparisons). For most outcomes, meta-analyses included data from a minority of trials. Only eight of 43 trials (19%) had an overall low risk of bias. Thirty five planned/ongoing randomised controlled trials could contribute 12 530 additional participants to future reviews. Conclusions Most trials on prenatal vitamin D published by September 2017 were small and of low quality. The evidence to date seems insufficient to guide clinical or policy recommendations. Future trials should be designed and powered to examine clinical endpoints, including maternal conditions related to pregnancy (such as pre-eclampsia), infant growth, and respiratory outcomes. Systematic review registration PROSPERO CRD42016051292

In Canada, little is known about how food parenting practices are associated with young children's dietary intakes and no studies have examined food parenting practices of Canadian fathers. This study aimed to examine associations between food parenting practices and preschool-age children's nutrition risk. We conducted a cross-sectional analysis of thirty-one 2-parent families; 31 mothers, 31 fathers, and 40 preschool-age children. Parents completed an adapted version of the Comprehensive Feeding Practices Questionnaire. We calculated children's nutrition risk using their NutriSTEP score. To account for sibling association, we used generalized estimating equations, adjusting for child age, sex, household income, and parental body mass index. Both mothers' and fathers' involvement of children in meal preparation were associated with lower child nutrition risk (mother [Formula: see text] = -3.45, p = 0.02; father [Formula: see text] = -1.74, p = 0.01), as were their healthy home environment scores (mother [Formula: see text] = -8.36, p < 0.001; father [Formula: see text] = -2.69, p = 0.04). Mothers' encouragement of balance and variety was associated with lower nutrition risk ([Formula: see text] = -8.88, p = 0.01), whereas mothers' use of food as a reward was associated with higher nutrition risk ([Formula: see text] = 4.67, p < 0.001). Fathers' modelling of healthy behaviours was associated with lower nutrition risk ([Formula: see text] = -2.21, p = 0.01), whereas fathers' restriction for health ([Formula: see text] = 2.21, p = 0.03) and pressure-to-eat scores ([Formula: see text] = 3.26, p = <0.001) were associated with higher nutrition risk. No associations were found between child nutrition status and parental emotion regulation, control, monitoring, or restriction for weight. In conclusion, both mothers' and fathers' food parenting practices are associated with their children's nutrition status. Fathers should be included in food parenting practices interventions.

Nearly all preschoolers in this study snacked daily, and consumed a variety of snack foods. Boys' and girls' snacking preferences begin to diverge early in life. Preschool children should be encouraged to consume healthful snacks.

Physical activity (PA) is a key determinant of health and development, yet few studies have examined PA levels and risk factors for low PA among young children in low- and middle-income countries. This study aimed to describe the PA and sedentary (SED) behavior levels of preschool-aged children in Dhaka, Bangladesh, and to estimate the associations between potential risk factors in the home built environment and moderate to vigorous PA (MVPA). In a sample of preschool-aged children (n = 65) in Dhaka, PA and SED behavior were measured for 7 days using ActiGraph GT3X-BT accelerometers. Characteristics of the home built environment, socioeconomic factors, and anthropometry were also measured. Linear mixed-effects models were used to estimate multivariable-adjusted associations between characteristics of the home environment and MVPA. Preschool-aged children spent a mean (±standard deviation) 421 ± 48 and 82 ± 23 min per day sedentary and in MVPA, respectively. There were no statistically significant associations between factors in the home built environment (indoor area, presence of an open stairwell, and presence of gross motor activity facilitating items) and MVPA. These findings suggest that the studied characteristics of the home built environment may not significantly influence the MVPA observed among preschool-aged children in Dhaka. Future research should focus on other structural and behavioral factors that facilitate PA among young children in dense urban settings.