BACKGROUNDCauses of early infant growth restriction remain incompletely understood. Where vitamin D deficiency is common, vitamin D supplementation during pregnancy and lactation may improve fetal-infant growth and other birth outcomes.METHODSWe conducted a randomized, double-blind, placebo-controlled trial of maternal vitamin D supplementation from 17-24 weeks gestation until birth or 6 months postpartum. Participants were randomly allocated to five vitamin D and/or placebo supplementation groups: (A) 0 IU/week, (B) 4200 IU/week, (C) 16800 IU/week, or (D) 28000 IU/week in pregnancy, all with 0 IU/week postpartum; or, (E) 28000 IU/week in prenatal and postpartum periods. The primary outcome was length-for-age z-score at one year of age according to World Health Organization child growth standards.RESULTSAmong 1164 infants assessed at one year of age (90% of 1300 pregnancies), there were no differences across groups in length-for-age z-scores (mean ±standard deviation): A: -0.93 ±1.05, B: -1.11 ±1.12, C: -0.97 ±0.97, D: -1.06 ±1.07, E: -0.94 ±1.00 (p=0.23). Groups were similar with respect to other anthropometric measures, birth outcomes, and morbidity. Vitamin D had dose- dependent effects on maternal and infant serum 25-hydroxyvitamin D and calcium, maternal urinary calcium excretion, and maternal parathyroid hormone concentrations. No clinical adverse events were attributed to the vitamin D intervention. CONCLUSIONSIn a population with widespread prenatal vitamin D deficiency and fetal/infant growth restriction, maternal vitamin D supplementation from mid-pregnancy until birth or 6 months postpartum does not influence fetal or infant growth, and has no beneficial or harmful effects on numerous other birth and infant outcomes.
Little valid information is available on human milk nutrient concentrations, especially for micronutrients (MN), and there are no valid Reference Values (RVs) across lactation. In this multi-center collaborative study, RVs will be established for human milk nutrients across the first 8.5 months postpartum. Well-nourished, unsupplemented women in Bangladesh, Brazil, Denmark, and The Gambia (n = 250/site) were recruited during the third trimester of pregnancy. Milk, blood, saliva, urine, and stool samples from mothers and their infants are collected identically at three visits (1–3.49, 3.5–5.99, 6.0–8.49 months postpartum). Milk analyses include macronutrients, selected vitamins, trace- elements and minerals, iodine, metabolomics, amino acids, human milk oligosaccharides, and bioactive peptides. We measure milk volume; maternal and infant diets, anthropometry, and morbidity; infant development, maternal genome, and the infant and maternal microbiome. RVs will be constructed based on methods for the WHO Child Growth Standards and the Intergrowth-21st Project. Clinical trials.gov registration number: NCT03254329.
Background We examined the effect of maternal vitamin D supplementation during pregnancy and lactation on risk of acute respiratory infection (ARI) in infants up to 6 months of age in Bangladesh. Methods This study was nested in a randomized, double-blind, placebo-controlled, 5-arm dose-ranging trial of prenatal and postpartum vitamin D supplementation. One group of women received 0 IU vitamin D per week during pregnancy and for 26 weeks post delivery (“placebo” group), one group received high-dose prenatal vitamin D supplementation of 28 000 IU per week and 26 weeks post delivery, and there were 3 additional dose-ranging groups receiving vitamin D supplementation during pregnancy only (4200, 16 800, and 28 000 IU per week, respectively). Episodes of ARI were identified by active and passive surveillance. The primary outcome was microbiologically confirmed ARI, and the primary analysis compared the high-dose prenatal plus postpartum vitamin D vs placebo groups. Results In total, 1174 mother-infant pairs were included. Among infants born to mothers in the placebo group, 98% had a venous umbilical cord 25(OH)D level below 30 nmol/L compared with none in the high-dose prenatal plus postdelivery vitamin D group. Incidence of microbiologically confirmed ARI in the high-dose prenatal plus postpartum vitamin D (1.21 episodes per 6 person-months; N = 235) and placebo groups (1.07 episodes per 6 person-months; N = 234) was not significantly different (hazard ratio of 1.12 [95% confidence intervals: 0.90-1.40]). There were no differences in the incidence of microbiologically confirmed or clinical ARI, upper, lower, or hospitalized lower respiratory tract infection between high-dose prenatal plus postpartum vitamin D and placebo groups. Conclusions Despite a high prevalence of maternal baseline vitamin D deficiency and significant effects of maternal vitamin D supplementation on infant vitamin D status, the intervention did not reduce the risk of microbiologically confirmed ARI in infants up to 6 months of age.
Background Causes of infant linear growth faltering in low-income settings remain poorly understood. Identifying age-specific risk factors in observational studies might be influenced by statistical model selection. Objectives To estimate associations of selected household factors and infant feeding behaviors within discrete age intervals with interval-specific changes in length-for-age z-scores (LAZs) or attained LAZ, using 5 statistical approaches. Methods Data from a birth cohort in Dhaka, Bangladesh (n = 1157) were analyzed. Multivariable-adjusted associations of infant feeding patterns or household factors with conditional LAZ (cLAZ) were estimated for 5 intervals in infancy. Two alternative approaches were used to estimate differences in interval changes in LAZ, and differences in end-interval attained LAZ and RRs of stunting (LAZ < −2) were estimated. Results LAZ was symmetrically distributed with mean ± SD = −0.95 ± 1.02 at birth and −1.00 ± 1.04 at 12 mo. Compared with exclusively breastfed infants, partial breastfeeding (difference in cLAZ: −0.11; 95% CI: −0.20, −0.02) or no breastfeeding (−0.30; 95% CI: −0.54, −0.07) were associated with slower growth from 0 to 3 mo. However, associations were not sustained beyond 6 mo. Modifiable household factors (smoking, water treatment, soap at handwashing station) were not associated with infant growth, attained size, or stunting. Alternative statistical approaches yielded mostly similar results as conditional growth models. Conclusions The entire infant LAZ distribution was shifted down, indicating that length deficits were mostly caused by ubiquitous or community-level factors. Early-infant feeding practices explained minimal variation in early growth, and associations were not sustained to 12 mo of age. Statistical model choice did not substantially alter the conclusions. Modifications of household hygiene, smoking, or early infant feeding practices would be unlikely to improve infant linear growth in Bangladesh or other settings where growth faltering is widespread.
Objectives Vitamin D may have an adjunctive role in the prevention and treatment of iron deficiency (ID) through its proposed role in the regulation of erythropoiesis and circulating hepcidin concentrations. Observational studies have shown associations between low vitamin D and iron status; however, there are few data from intervention trials. In participants of the Maternal Vitamin D for Infant Growth Trial (MDIG; NCT01924013), among whom the baseline prevalence of vitamin D deficiency was 64%, we examined the effect of prenatal vitamin D supplementation on iron status during pregnancy by testing the effect of vitamin D supplementation on serum ferritin concentrations. Methods In this double-blind, dose-response, randomized trial in Dhaka, Bangladesh, women were recruited at 17–24 weeks’ gestation and randomly assigned to receive a prenatal vitamin D3 dose of 4200, 16,800, 28,000 IU/week or placebo. Serum ferritin was quantified using an electro-chemiluminescence immunoassay. Plasma C-reactive protein (CRP) was analysed by enzyme-linked immunoassay. Linear regression was used to test the hypothesized effect of vitamin D supplementation on serum ferritin (n = 1011 of 1300 enrolled). In a sensitivity analysis, we adjusted for concurrent CRP to correct for inflammation (n = 920). Regression correction was used to generate an inflammation-corrected estimate of the prevalence of ID (n = 920). Results Prevalence of ID (serum ferritin <15 µg/L) was high overall (27% corrected for inflammation; 12% uncorrected). Geometric mean (95% confidence interval) serum ferritin concentrations were lower in each of the vitamin D supplementation groups [43.1 (38.1, 48.7), 44.8 (40.4, 49.7) and 45.1 (41.5, 49.1) µg/L in the 4200, 16,800 and 28,000 IU/week groups, respectively] compared to the placebo group [50.3 µg/L (45.0, 56.2)], although none of the pairwise differences between each vitamin D group and placebo were statistically significant at the P < 0.05 threshold. Adjusting for CRP did not change the inferences. Conclusions In a population with concurrently high prevalence rates of iron and vitamin D deficiency, prenatal vitamin D supplementation did not lead to improvements in iron status by late gestation. The possibility of a negative effect of vitamin D supplementation on iron status should be further explored. Funding Sources The Bill and Melinda Gates Foundation.
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