Effect Of Maternal Vitamin Research Articles

Effects of maternal vitamin D supplementation on childhood health.

Vitamin D deficiency during pregnancy is associated with an increased risk of health issues in the offspring. Accordingly, recent Endocrine Society guidelines strongly support supplementation in pregnancy, also underlining that without consensus on optimal maternal vitamin D levels, routine screening is currently irrelevant. Knowledge of organ-specific effects of vitamin D and its association with maternal vitamin D status may aid to optimize vitamin D supplementation. This systematic review outlines the proposed next-generation effects of vitamin D supplementation ≥ 400 IU/d, and explores whether such effects are attributed to a specific maternal vitamin D level obtained during pregnancy. A systematic literature search was conducted in PubMed and Embase according to the PRISMA guidelines, focusing on health outcomes from ten days post-partum and beyond. Of the 2,383 screened articles, 39 were included. In 11 of 16 studies, vitamin D supplementation reduced respiratory tract infections in the first years of life. Growth or bone development benefits were observed in six of 12 studies. Positive effects on neurodevelopment and reduced autoimmune risk (diabetes-related antibodies) were noted, although further research is needed to determine the role of vitamin D. Very few studies have measured vitamin D concentrations, but even 1,600 IU/d supplementation was associated with high frequency of infant vitamin D insufficiency. Current recommendations may not ensure sufficient vitamin D levels at birth, among others, increasing the risk of early-life infections. Further studies linking maternal and infant vitamin D levels to specific outcomes would aid in personalized nutritional advice during pregnancy and improve next-generation health.

Influences of Maternal Nutrition and Lifestyle Factors on Early Childhood Oral Health: A Systematic Review of Mechanisms and Intervention Strategies.

This systematic review and meta-analysis examined the impact of maternal nutrition and lifestyle factors on early childhood oral health. The review focused on the effects of maternal vitamin D levels and smoking during pregnancy on children's dental health outcomes. A comprehensive literature search was conducted across PubMed, Scopus, and Web of Science, yielding 23 that were included for analysis. The quality of the studies was assessed using the Newcastle-Ottawa Scale. The effect estimates were pooled through a random effect model. All analyses were carried out using the R program. Most studies in our systematic review showed a significant association between maternal vitamin D and smoking during pregnancy and childhood dental health outcomes. Meta-analysis revealed a significant association between maternal vitamin D levels and children's dental health (OR = 1.30, 95% CI: 0.49 to 3.45, p < 0.001). Maternal smoking during pregnancy was strongly linked to an increased risk of childhood dental caries (OR = 0.3290, 95% CI: 0.2089-0.4491, p < 0.0001). These findings underscore the crucial role of maternal health behaviors in shaping children's oral health trajectories. This study emphasizes the need for integrated public health interventions promoting healthier maternal behaviors and early preventive dental care.

131 DNA methylation profile in bovine fetal liver is affected by maternal vitamin and mineral supplementation during early gestation

Abstract Early gestation is the critical period for successful pregnancy establishment. During this period, maternal nutrition affects fetal development with potentially long-lasting consequences on offspring performance. Despite the known effects of vitamins and minerals on embryonic development, supplementation is still not a widely adopted practice. Here we focused on the effects of maternal vitamin and mineral supplementation from pre-breeding to d 83 of gestation. We hypothesized that the DNA methylation pattern of genes involved with fetal hepatic metabolism and function would be altered in response to vitamin and mineral supplementation during early gestation. Sixteen Angus crossbred heifers (~16 mo of age) were randomly assigned to either a treatment (vitamin and mineral supplementation, VTM, n = 8) or control (corn-based carrier without supplementation, NoVTM, n = 8) group. Supplemented heifers received 0.45 kg •heifer-1•d-1 of to provide 113 g of vitamin-mineral premix (Purina Wind &amp; Rain Storm All-Season 7.5 Complete, Land O’Lakes, Inc., Arden Hills, MN) from d 71 to 148 before breeding to d 83 of gestation. All heifers received 100% of NRC recommended nutritional requirements targeting 0.28 kg •heifer-1•d-1 of gain. The heifers were bred through artificial insemination following a 7-d Co-Synch + CIDR estrus synchronization protocol. All pregnant heifers were surgically ovariohysterectomized on d 83, and liver samples were collected from the fetuses. DNA methylation profiles from 16 fetuses (8 per treatment) were determined using Reduced Representation Bisulfite Sequencing (RRBS). The analysis was conducted using methylKit pipeline where data was normalized using principal components. We identified 794 differentially methylated cytosines (DMCs) for the control (NoVTM) vs VTM comparison. Most of the DMCs were found in introns followed by intergenic, promoter, and exonic regions. Among these DMCs, 60% (479) were hypermethylated and 40% (315) were hypomethylated, potentially regulating 739 nearby genes (FDR &amp;lt; 0.1). Biological processes over-represented by these genes included transport of ions through voltage gated channels (KCNK13, KCNT1, CACNA1B, KCNK9, LRRC55, KCNAB2, CACNA1S, KCNJ2, CACNG5, CLIC5, TPCN2, KCNQ1), which may be associated to pregnancy establishment by inducing pregnancy-associated relaxation and uterine artery dilatation. Some genes associated with structural development were also regulated by VTM supplementation (i.e., TIAM1, COL18A1, DYSF, BMP10, RXRA, EHMT1, COL4A2, PLEC, ZFAT, MTMR2, NAV1, ANHX, ACACB, and LIMK2). Collectively, these results suggest that periconceptual maternal vitamin and mineral supplementation affects the methylation pattern and potentially regulates the expression of genes involved in fetal liver development and ion transport.

P17-040-23 Effects of Maternal Vitamin D Supplementation on Maternal and Infant Biomarkers of Environmental Enteric Dysfunction: A Secondary Analysis of a Randomized Controlled Trial

P17-040-23 Effects of Maternal Vitamin D Supplementation on Maternal and Infant Biomarkers of Environmental Enteric Dysfunction: A Secondary Analysis of a Randomized Controlled Trial

The Effect of Maternal Vitamin D Intake on the Incidence of Nonspecific Respiratory Distress in Infants: A Randomized Clinical Trial

Background: Vitamin D deficiency is associated with respiratory problems in neonates. The late preterm or near-term neonates who have been admitted for tachypnea and fully recovered before 12 h are called non-specific respiratory distress syndrome (NRDS) cases. The present study aimed to evaluate the effect of 25-hydroxy vitamin D administration in pregnant women at risk of preterm delivery on the incidence of NRDS in their newborns. Methods: This single-blind clinical trial was performed on mothers and neonates with a gestational age of 32–37 weeks who were referred with labor pains from February 20, 2021 to June 29, 2021 to the Obstetrics and Gynecology Department and intensive care unit of Ghaem Hospital, affiliated to Mashhad University of Medical Sciences, Iran. Within 72 h before premature delivery, a dose of 50,000 units of 25 hydroxyvitamin D was injected intramuscularly to pregnant women in the intervention group. A sample containing 1.5 mL of whole blood was collected from the umbilical cord of the infant and mother to assess the level of 25-hydroxy vitamin D. Results: In the present study, there was a significant difference between the two groups of control and intervention in terms of infant’s weight (p = 001), 1-minute (p = 0.027) and 5-minute Apgar scores (p = 0.001), the incidence of NRDS (p = 0.001), and the maternal age (p = 0.004). However, the results showed no statistically significant difference between the two groups in terms of gender (p = 0.673), type of delivery (p = 0.299), level of 25-hydroxy(OH) vitamin D of the mother (p = 0.053), and infant (p = 0.805). Conclusions: A single injection of vitamin D into the mother prone to preterm birth over 31 weeks of gestation reduces transient respiratory problems in their newborns. Clinical Trial Registration: The study was also registered in the Iranian Clinical Trial Registration Center (IRCT20110807007244N7).

Maternal vitamin D deficiency and brain functions: a never-ending story.

A large number of observational studies have highlighted the prevalence rates of vitamin D insufficiency and deficiency in many populations including pregnant women. Vitamin D is well known to have a crucial role in differentiation and proliferation, as well as neurotrophic and neuroprotective actions in the brain. It has been observed that this micronutrient can modulate neurotransmission and synaptic plasticity. Recent results from animal and epidemiological studies indicated that maternal vitamin D deficiency is associated with a wide range of neurobiological diseases including autism, schizophrenia, depression, multiple sclerosis and developmental defects. The aim of this review is to summarize the current state of knowledge on the effect of maternal vitamin D deficiency on brain functions and development.

A bibliometric analysis of global research on vitamin D and reproductive health between 2012 and 2021: Learning from the past, planning for the future.

BackgroundVitamin D plays an invaluable role in reproductive health, but vitamin D insufficiency and deficiency are generally common among couples of childbearing age and pregnant women. This study aimed to evaluate the evolution, development trend, and research hotspot of publications on vitamin D and reproductive health.MethodsThe literature on vitamin D and reproductive health between 2012 and 2021 was retrieved from the Web of Science Core Collection (WoSCC). We used VOSviewer and CiteSpace to analyze publication years, countries, institutions, journals, highly cited authors and publications, and co-occurrence and citation bursts of keywords.ResultsA total of 1,828 articles and reviews on vitamin D and reproductive health published between 2012 and 2021 were identified. The annual publication outputs showed steady growth, with the most publications (272) and citations (7,097) in 2021. The United States contributed the most publications (458) and had the highest h-index (58). In terms of the number of publications and h-index, the journal named Nutrients ranked first. Nutrition dietetics, obstetrics gynecology, and endocrinology metabolism were three well-represented disciplines in research on vitamin D and reproductive health. Hollis BW, Wagner CL, and Litonjua AA were the top three most productive authors in this field during the last decade. Apart from vitamin D, the five keywords with the most frequent occurrence were vitamin D deficiency, pregnancy, risk, vitamin D supplementation, and 25-hydroxyvitamin D. Keyword citation burst analysis revealed that low birth weight, adipose tissue, marker, and embryo had a citation burst lasting until 2021.ConclusionIn conclusion, vitamin D has received continuous attention in the field of reproductive health, and there appears to have a higher level of research in North America. Multidisciplinary intersection contributed to the in-depth exploration in this field. And the effect of maternal vitamin D levels on fetal lipid metabolism and the prediction of fertility by vitamin D-related markers might be hotspots for the research.

Effects of vitamin D supplementation during pregnancy on offspring health at birth: A meta-analysis of randomized controlled trails

Vitamin D deficiency during pregnancy is common across the world. The effects of maternal vitamin D supplementation on offspring health were contradict from previous studies. This study was conducted to update the effects of vitamin D supplementation during pregnancy on offspring health with new evidence. A systematic search of Medline, Embase, the Cochrane Database of Systematic Reviews, ClinicalTrials.gov and ChiCTR.org.cn through July 2021 were conducted. Studies were included if they reported randomized clinical trials comparing vitamin D supplementation with placebo, no supplementation (400IU/day or less) during pregnancy, and included birth outcomes. Pooled analyses were performed using random-effects models. Forty-two RCTs recruiting 11,082 participants were included. Vitamin D supplementation during pregnancy was associated with a lower risk of intrauterine or neonatal death (RR, 0.69; 95% CI, 0.48-0.99) in 13 RCTs with 6238 participants. We also found prenatal vitamin D supplementation was associated with an increased offspring length at birth (MD, 0.27cm; 95% CI, 0.02-0.51), increased neonatal vitamin D concentration (MD, 27.72nmol/L; 95% CI, 20.51-34.92), and reduced risk of vitamin D insufficiency (RR of 0.51; 95% CI, 0.38-0.67), but not associated with birth weight (MD, 37.07g; 95% CI,-9.67 to 83.80), head circumference (MD, 0.15cm; 95% CI,-0.02 to 0.32), preterm birth (RR, 0.93; 95% CI, 0.79-1.09), or low birth weight (RR, 0.90; 95% CI, 0.66-1.24). Supplementation initiated before the 20th week of gestation was associated with a decreased risk of small for gestational age (RR, 0.46; 95% CI, 0.24-0.90). Vitamin D supplementation during pregnancy was associated with improved offspring vitamin D sufficiency status, improved fetal linear growth, and reduced fetal or neonatal mortality. No effect was demonstrated for vitamin D supplementation on birth weight, risk of low birth weight, and risk of preterm birth.

Effectiveness of maternal vitamin D supplementation on maternal and fetal outcomes among antenatal mothers

Vitamin D is a fat-soluble lipophilic prohormone. Vitamin D is synthesized in human body inresponse to UV light. The significance of vitamin D have been documented in a large number of experimental researches that support relationship between vitamin D status and human health. The chief identified impacts of vitamin D on human body is bone health, pregnant women health, foetal health, mineral homeostasis, anti-inflammatory etc. Aim of the present review is to summarize the impact of maternal vitamin D supplementation on maternal-fetal outcomes, to identify the most commonly used tools for measuring maternal vitamin D supplementation, and report on the maternal and foetal outcomes of maternal vitamin D supplementation. The deficiency of Vitamin D in pregnant women and neonates is a common problem that affects people all over the world. The preterm birth risk is increased by 60% in pregnant mothers when the maternal 25-OH-D concentration is less than 40 µg/ml. The research articles consider for the present systemic review meet the following criteria: (i) A non-intervention, intervention and quantitative research studies to look at the effects of maternal vitamin D supplementation on maternal and foetal outcomes, and (ii) the article was published in peer-reviewed journals.

Effect of maternal vitamin D status on risk of adverse birth outcomes: a systematic review and dose-response meta-analysis of observational studies.

Accumulating evidence suggests that vitamin D deficiency increases the risk of adverse perinatal outcomes. However, the dose-response relationship between maternal vitamin D status and adverse birth outcomes remains unclear. Focusing on prospective observational studies, we aimed to explore the dose-response relationship of vitamin D status with the risk of low birth weight (LBW), macrosomia (MA), preterm birth (PTB), small for gestational age (SGA), and intrauterine growth restriction (IUGR). Databases including PubMed, Embase, Scopus, and Web of Science were used up to 19 January 2021 to search for observational studies that fulfilled criteria as follows: cohort studies, case-cohort studies, or nested case-control studies. Random-effects models were used to pool relative risks (RRs) and 95% confidence intervals (CIs) in the observational studies. A total of 72 publications were included in this systematic review and 71 in the meta-analysis. Maternal 25-hydroxyvitamin D (25(OH)D) concentrations were inversely associated with the risk of LBW (RR: 0.65; 95% CI 0.48-0.86), PTB (RR: 0.67; 95% CI 0.57-0.79), and SGA (RR: 0.61; 95% CI 0.49-0.76) in the highest versus lowest meta-analysis, but not associated with MA and IUGR. Linear dose-response analysis showed that each 25nmol/L increase in 25(OH)D was associated with a 6% and 10% reduction in the risk of PTB (RR: 0.94; 95% CI 0.90-0.98) and SGA (RR: 0.90; 95% CI 0.84-0.97), respectively. Our study suggests that a sufficient vitamin D status during pregnancy is protective against the risk of LBW, PTB, and SGA.

Effect of maternal vitamin D supplementation on nasal pneumococcal acquisition, carriage dynamics and carriage density in infants in Dhaka, Bangladesh

BackgroundInvasive pneumococcal disease is a major cause of infant morbidity and death worldwide. Vitamin D promotes anti-pneumococcal immune responses in vitro, but whether improvements in infant vitamin D status modify risks of nasal pneumococcal acquisition in early life is not known.MethodsThis is a secondary analysis of data collected in a trial cohort in Dhaka, Bangladesh. Acute respiratory infection (ARI) surveillance was conducted from 0 to 6 months of age among 1060 infants of women randomized to one of four pre/post-partum vitamin D dose combinations or placebo. Nasal swab samples were collected based on standardized ARI criteria, and pneumococcal DNA quantified by qPCR. Hazards ratios of pneumococcal acquisition and carriage dynamics were estimated using interval-censored survival and multi-state modelling.ResultsPneumococcal carriage was detected at least once in 90% of infants by 6 months of age; overall, 69% of swabs were positive (2616/3792). There were no differences between any vitamin D group and placebo in the hazards of pneumococcal acquisition, carriage dynamics, or carriage density (p > 0.05 for all comparisons).ConclusionDespite in vitro data suggesting that vitamin D promoted immune responses against pneumococcus, improvements in postnatal vitamin D status did not reduce the rate, alter age of onset, or change dynamics of nasal pneumococcal colonization in early infancy.Trial registration Registered in ClinicalTrials.gov with the registration number of NCT02388516 and first posted on March 17, 2015.

Effect of Maternal Vitamin D and Serum Calcium Levels on Mode of Delivery

Effect of Maternal Vitamin D and Serum Calcium Levels on Mode of Delivery

Effects of maternal vitamin D&lt;sub&gt;3&lt;/sub&gt; status on meat quality and fatty acids composition in offspring pigs

1. Du M., Tong J., Zhao J., Underwood K.R., Zhu M., Ford S.P., Nathanielsz P.W., 2010a. Fetal programming of skeletal muscle development in ruminant animals. J. Anim. Sci. 88, Suppl. 13, E51–E60, https://doi.org/10.2527/jas.20.... CrossRef Google Scholar

Molecular regulation of lung maturation in near-term fetal sheep by maternal daily vitamin C treatment in late gestation

BackgroundIn the fetus, the appropriate balance of prooxidants and antioxidants is essential to negate the detrimental effects of oxidative stress on lung maturation. Antioxidants improve respiratory function in postnatal life and adulthood. However, the outcomes and biological mechanisms of antioxidant action in the fetal lung are unknown.MethodsWe investigated the effect of maternal daily vitamin C treatment (200 mg/kg, intravenously) for a month in late gestation (105–138 days gestation, term ~145 days) on molecular regulation of fetal lung maturation in sheep. Expression of genes and proteins regulating lung development was quantified in fetal lung tissue. The number of surfactant-producing cells was determined by immunohistochemistry.ResultsMaternal vitamin C treatment increased fetal lung gene expression of the antioxidant enzyme SOD-1, hypoxia signaling genes (HIF-2α, HIF-3α, ADM, and EGLN-3), genes regulating sodium movement (SCNN1-A, SCNN1-B, ATP1-A1, and ATP1-B1), surfactant maturation (SFTP-B and ABCA3), and airway remodeling (ELN). There was no effect of maternal vitamin C treatment on the expression of protein markers evaluated or on the number of surfactant protein-producing cells in fetal lung tissue.ConclusionsMaternal vitamin C treatment in the last third of pregnancy in sheep acts at the molecular level to increase the expression of genes that are important for fetal lung maturation in a healthy pregnancy.ImpactMaternal daily vitamin C treatment for a month in late gestation in sheep increases the expression of gene-regulating pathways that are essential for normal fetal lung development.Following late gestation vitamin C exposure in a healthy pregnancy, an increase in lung gene but not protein expression may act as a mechanism to aid in the preparation for exposure to the air-breathing environment after birth.In the future, the availability/development of compounds with greater antioxidant properties than vitamin C or more specific targets at the site of oxidative stress in vivo may translate clinically to improve respiratory outcomes in complicated pregnancies at birth.

Comparison of vitamin D, calcium and phosphorus values of essential hypertensive, preeclamptic and normotensive pregnant women

Abstract&#x0D; Objective: The aim of this study is; to examine the levels of 25 hydroxy vitamin D (25-OH D), calcium (Ca) and phosphorus (P) in preeclamptic, essential hypertensive and normotensive pregnant groups.&#x0D; Material and Method: A total of 120 pregnant women who came to our clinic for delivery between 35 and 40 weeks of gestation between April 2017 and November 2017 were included in the study. The study group consisted of 40 preeclamptic (n = 40) and 40 essential hypertensive (n = 40), and the control group consisted of 40 normotensive pregnant women (n = 40). The demographic, obstetric and laboratory results of the three groups were compared in terms of 25-OH D levels, calcium and phosphorus levels.&#x0D; Results: Maternal age, BMI and proteinuria were significantly lower in the preeclamptic and essential hypertensive group compared to the control group (p &lt;0.05). Week of gestation was observed to be earlier in the preeclamptic group compared to the other two groups (p &lt;0.05). The mean systolic and diastolic blood pressure of the preeclamptic and essential hypertensive groups were found to be statistically significantly higher than the control group (p &lt;0.05). No statistically significant difference was found between the groups in terms of transaminase. It was found that creatinine in the control group was statistically lower than the average creatinine level in the other two groups (p &lt;0.001). The Blood Urea Nitrogen (BUN) average of the control group was statistically significantly lower than the average of the other two groups (p = 0.001). Phosphorus levels were significantly higher in preeclamptic and essential hypertensive pregnant women compared to normotensive pregnant women (p&lt;0.05). However, no statistically significant difference was found between calcium and 25-OH D levels in all three groups.&#x0D; Conclusion: Low phosphorus level is likely to play a role in the etiology of essential hypertension and preeclampsia. The effects of maternal vitamin D and calcium level on the development of preeclampsia are uncertain, but more extensive research is required on potential positive effects.

Effects of maternal vitamin D&lt;sub&gt;3&lt;/sub&gt; on quality and water distribution in pork of offspring pigs during frozen storage

1. Aaslyng M.D., Bejerholm C., Ertbjerg P., Bertram H.C., Andersen H.J., 2003. Cooking loss and juiciness of pork in relation to raw meat quality and cooking procedure. Food Quality and Preference. 14, 277–288, https://doi.org/10.1016/S0950-.... CrossRef Google Scholar

The effect of maternal vitamin D levels on placental shear wave elastography findings in the first trimester

The aim of this study was to investigate the effect of maternal serum Vitamin D levels on the elasticity of placenta. Seventy-four spontaneously conceived singleton pregnancies in their first trimester were enrolled into this study. Fifty-one of them had Vitamin D deficiency (<20 ng/mL), while 23 pregnancies had Vitamin D levels ≥20 ng/mL. The placental elasticity was measured by the transabdominal Point Shear Wave Elastography (pSWE) method. In each case, the mean of 10 consecutive measurements was accepted as the mean placental elasticity value. The mean pSWE values did not significantly differ between the Vitamin D deficient group and the control group (p > .05). Placental elasticity was not found to be different in the pregnancies with Vitamin D deficiency during the first trimester. IMPACT STATEMENT What is already known on this subject? The pSWE technique provides opportunity to determine the elasticity of any interested tissue. Placental elasticity has been found to be changed in inflammatory and fibrotic conditions such as in preeclampsia, intrauterine growth restriction or diabetes. On the other hand, Vitamin D deficiency is linked with several comorbidities such as autoimmune disorders, cancer and cardiovascular disorders. Vitamin D also plays a role in placental angiogenesis in the first trimester. Maternal Vitamin D levels are shown to be related with adverse pregnancy outcomes. What do the results of this study add? To the best of our knowledge, this study is the first assessing the association between Vitamin D levels and placental elasticity. Placental elasticity was not found to be changed by Vitamin D deficiency. What are the implications of these findings for clinical practice and/or further research? Our pilot study revealed that Vitamin D deficiency does not have any impact on placental elasticity in the first trimester. However, longitudinal studies concerning placental elasticity in subsequent trimesters are needed to support our findings.

Effects of maternal vitamin D&lt;sub&gt;3&lt;/sub&gt; concentration during pregnancy on adipogenic genes expression and serum biochemical index in offspring piglets

1. Belenchia A.M., Jones K.L., Will M., Beversdorf D.Q., Vieira-Potter V., Rosenfeld C.S., Peterson C.A., 2018. Maternal vitamin D deficiency during pregnancy affects expression of adipogenic-regulating genes peroxisome proliferator-activated receptor gamma (PPARgamma) and vitamin D receptor (VDR) in lean male mice offspring. Eur. J. Nutr. 57, 723−730, https://doi.org/10.1007/s00394.... CrossRef Google Scholar

Vitamin D supplementation during pregnancy: an overview.

Examine recent evidence of randomized controlled trials and meta-analyses regarding the effect of maternal vitamin D status and supplementation over obstetrical and offspring outcomes. Maternal serum 25-hydroxyvitamin [25(OH)D] progressively declines during pregnancy because of fetal physiological demands and adjustments. Vitamin D supplementation during pregnancy in women with low vitamin D status may improve fetal growth and reduce the risks for small-for-gestational-age, preeclampsia, preterm birth, and gestational diabetes. Mothers with sufficient vitamin D levels have offsprings with less enamel defects and less attention deficit and hyperactive disorders and autism. All pregnant women should be supplemented with 600 IU/day of vitamin D3. We discuss evidence indicating that higher vitamin D doses (1000-4000 IU/day) may be convenient to achieve better maternal and infant outcomes. Low maternal vitamin D status during pregnancy may be associated in infants with a higher risk for lower bone mineral content, enamel defects and attention deficit hyperactive disorder. Recent evidence from vitamin D intervention studies and meta-analyses of a large number of studies support vitamin D supplementation during pregnancy to improve maternal, fetal and, immediate and later offspring health.

Effect of Maternal Vitamin D Supplementation on Iron Status During Pregnancy

Abstract 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 &amp;lt;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 &amp;lt; 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.