Project description:Introduction:Maternal vitamin D status in pregnancy has been linked to many health outcomes in mother and offspring. A wealth of observational studies have reported on both obstetric outcomes and complications, including pre-eclampsia, gestational diabetes, mode and timing of delivery. Many foetal and childhood outcomes are also linked to vitamin D status, including measures of foetal size, body composition and skeletal mineralization, in addition to later childhood outcomes, such as asthma. Sources of data:Synthesis of systematic and narrative reviews. Areas of agreement and controversy:The findings are generally inconsistent in most areas, and, at present, there is a lack of data from high-quality intervention studies to confirm a causal role for vitamin D in these outcomes. In most areas, the evidence tends towards maternal vitamin D being of overall benefit, but often does not reach statistical significance in meta-analyses. Growing points and areas timely for developing research:The most conclusive evidence is in the role of maternal vitamin D supplementation in the prevention of neonatal hypocalcaemia; as a consequence the UK department of health recommends that pregnant women take 400 IU vitamin D daily. High-quality randomized placebo-controlled trials, such as the UK-based MAVIDOS trial, will inform the potential efficacy and safety of vitamin D supplementation in pregnancy across a variety of outcomes.
Project description:BackgroundVitamin D deficiency or insufficiency is thought to be common among pregnant women. Vitamin D supplementation during pregnancy has been suggested as an intervention to protect against adverse gestational outcomes.ObjectivesTo examine whether supplements with vitamin D alone or in combination with calcium or other vitamins and minerals given to women during pregnancy can safely improve maternal and neonatal outcomes.Search methodsWe searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 October 2011), the International Clinical Trials Registry Platform (ICTRP) (31 October 2011), the Networked Digital Library of Theses and Dissertations (28 October 2011) and also contacted relevant organisations (8 April 2011).Selection criteriaRandomised and quasi-randomised trials with randomisation at either individual or cluster level, evaluating the effect of supplementation with vitamin D alone or in combination with other micronutrients for women during pregnancy.Data collection and analysisTwo review authors independently i) assessed the eligibility of studies against the inclusion criteria ii) extracted data from included studies, and iii) assessed the risk of bias of the included studies. Data were checked for accuracy.Main resultsThe search strategy identified 34 potentially eligible references. We included six trials assessing a total of 1023 women, excluded eight studies, and 10 studies are still ongoing. Five trials involving 623 women compared the effects of vitamin D alone versus no supplementation/placebo and one trial with 400 women compared the effects of vitamin D and calcium versus no supplementation.Only one trial with 400 women reported on pre-eclampsia: women who received 1200 IU vitamin D along with 375 mg of elemental calcium per day were as likely to develop pre-eclampsia as women who received no supplementation (average risk ratio (RR) 0.67; 95% confidence interval (CI) 0.33 to 1.35). Data from four trials involving 414 women consistently show that women who received vitamin D supplements had higher concentrations of vitamin D in serum at term than those women who received no intervention or a placebo; however the magnitude of the response was highly heterogenous. Data from three trials involving 463 women suggest that women who receive vitamin D supplements during pregnancy less frequently had a baby with a birthweight below 2500 grams than those women receiving no treatment or placebo; statistical significance was borderline (RR 0.48; 95% CI 0.23 to 1.01).In terms of other conditions, there were no significant differences in adverse side effects including nephritic syndrome (RR 0.17; 95% CI 0.01 to 4.06; one trial, 135 women); stillbirths (RR 0.17; 95% CI 0.01 to 4.06; one trial, 135 women) or neonatal deaths (RR 0.17; 95% CI 0.01 to 4.06; one trial, 135 women) between women who received vitamin D supplements in comparison with women who received no treatment or placebo. No studies reported on preterm birth, maternal death, admission to neonatal intensive care unit/special nursery or Apgar scores.Authors' conclusionsVitamin D supplementation in a single or continued dose during pregnancy increases serum vitamin D concentrations as measured by 25-hydroxyvitamin D at term. The clinical significance of this finding and the potential use of this intervention as a part of routine antenatal care are yet to be determined as the number of high quality trials and outcomes reported is too limited to draw conclusions on its usefulness and safety. Further rigorous randomised trials are required to evaluate the role of vitamin D supplementation in pregnancy.
Project description:BackgroundIt is unclear whether maternal vitamin D supplementation during pregnancy and lactation improves fetal and infant growth in regions where vitamin D deficiency is common.MethodsWe conducted a randomized, double-blind, placebo-controlled trial in Bangladesh to assess the effects of weekly prenatal vitamin D supplementation (from 17 to 24 weeks of gestation until birth) and postpartum vitamin D supplementation on the primary outcome of infants' length-for-age z scores at 1 year according to World Health Organization (WHO) child growth standards. One group received neither prenatal nor postpartum vitamin D (placebo group). Three groups received prenatal supplementation only, in doses of 4200 IU (prenatal 4200 group), 16,800 IU (prenatal 16,800 group), and 28,000 IU (prenatal 28,000 group). The fifth group received prenatal supplementation as well as 26 weeks of postpartum supplementation in the amount of 28,000 IU (prenatal and postpartum 28,000 group).ResultsAmong 1164 infants assessed at 1 year of age (89.5% of 1300 pregnancies), there were no significant differences across groups in the mean (±SD) length-for-age z scores. Scores were as follows: placebo, -0.93±1.05; prenatal 4200, -1.11±1.12; prenatal 16,800, -0.97±0.97; prenatal 28,000, -1.06±1.07; and prenatal and postpartum 28,000, -0.94±1.00 (P=0.23 for a global test of differences across groups). Other anthropometric measures, birth outcomes, and morbidity did not differ significantly across groups. Vitamin D supplementation had expected effects on maternal and infant serum 25-hydroxyvitamin D and calcium concentrations, maternal urinary calcium excretion, and maternal parathyroid hormone concentrations. There were no significant differences in the frequencies of adverse events across groups, with the exception of a higher rate of possible hypercalciuria among the women receiving the highest dose.ConclusionsIn a population with widespread prenatal vitamin D deficiency and fetal and infant growth restriction, maternal vitamin D supplementation from midpregnancy until birth or until 6 months post partum did not improve fetal or infant growth. (Funded by the Bill and Melinda Gates Foundation; ClinicalTrials.gov number, NCT01924013 .).
Project description:The mechanism of cytochrome P450 2D6 (CYP2D6) induction during pregnancy has not been evaluated in humans. This study assessed the changes in CYP2D6 and CYP3A activities during pregnancy and postpartum, and the effect of vitamin A administration on CYP2D6 activity. Forty-seven pregnant CYP2D6 extensive metabolizers (with CYP2D6 activity scores of 1 to 2) received dextromethorphan (DM) 30 mg orally as a single dose during 3 study windows (at 25 to 28 weeks of gestation, study day 1; at 28 to 32 weeks of gestation, study day 2; and at ≥3 months postpartum, study day 3). Participants were randomly assigned to groups with no supplemental vitamin A (control) or with supplemental vitamin A (10 000 IU/day orally for 3 to 4 weeks) after study day 1. Concentrations of DM and its metabolites, dextrorphan (DX) and 3-hydroxymorphinan (3HM), were determined from a 2-hour post-dose plasma sample and cumulative 4-hour urine sample using liquid chromatography-mass spectrometry. Change in CYP2D6 activity was assessed using DX/DM plasma and urine metabolic ratios. The activity change in CYP3A was also assessed using the 3HM/DM urine metabolic ratio. The DX/DM urine ratio was significantly higher (43%) in pregnancy compared with postpartum (P = .03), indicating increased CYP2D6 activity. The DX/DM plasma ratio was substantially higher in the participants, with an activity score of 1.0 during pregnancy (P = .04) compared with postpartum. The 3HM/DM urinary ratio was significantly higher (92%) during pregnancy, reflecting increased CYP3A activity (P = .02). Vitamin A supplementation did not change CYP2D6 activity during pregnancy; however, plasma all-trans retinoic acid (atRA) concentrations were positively correlated with increased CYP2D6 activity during pregnancy and postpartum. Further research is needed to elucidate the mechanisms of increased CYP2D6 activity during pregnancy.
Project description: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 <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.
Project description:IntroductionThe aim of the study was to identify the consumption of vitamin and folic acid supplements before and during pregnancy in a group of post-partum women (Romanian, Hungarian, and Roma) from Mureș County, Romania, and the influence of socio-economic and behavioral factors on the consumption of vitamins.Materials and methodsThis cross-sectional questionnaire-based study included 1278 post-partum women (during the three days of hospitalization for birth), average age 29.5, registered for giving birth in the three hospitals in Mureș County, 2015-2016.ResultsIn our sample, 69.58% of the interviewed women did not use any vitamin and folic acid supplements before pregnancy, while 30.70% did not use vitamin supplements during pregnancy. The lack of vitamin supplementation during pregnancy was associated with the low birth weight (<2500 g) of newborns (OR = 2.4, 95% CI [1.6-3.8]) and birth at under 36 weeks of gestation (OR = 0.5, 95% CI [0.2-0.8]).ConclusionThe use of vitamin supplements, including folic acid, continues to be deficient among Romanian women before getting pregnant, as well as during their pregnancy. We observed a lack of vitamin supplementation for pregnant women even if they were influenced by risk factors. This highlights the importance of promoting the benefits of vitamin supplementation equally among all subjects.
Project description:BACKGROUND:Despite favorable climatic conditions, vitamin D deficiency (VDD) is widespread in Pakistan. Current study was aimed to evaluate the prevalence of VDD in Pakistani pregnant women and effectiveness of various regimen of Vitamin D supplementation. METHODOLOGY:This hospital-based prospective cohort study included pregnant women at 12th to 24th weeks of gestation attending Gynae clinic from October 2018 to April 2019. Patients were classified into control and treatment groups (Groups: G1, G2 and G3) according to the dose of vitamin D supplementation. Patients received various regimens of vitamin D including 2000 IU/day (G1), 5000 IU/day (G2) and stat 200000 IU (G3). The levels of vitamin D were measured before and after supplementation. The effectiveness of dosages were compared between and within the groups. Moreover, factors associated with vitamin D sufficiency and insufficiency were ascertained using appropriate statistical methods. RESULTS:Among 281 pregnant women (mean age: 28.22 ± 4.61 years), VDD was prevalent in 47.3% cases. Vitamin D supplementation caused significant rise in the levels 25(OH)D in treatment groups, while there was no significant difference in control group. The highest mean increment in vitamin D (23.14 ± 11.18 ng/ml) was observed with dose 5000 IU/day followed by doses 200000 IU stat (21.06 ± 13.73 ng/ml) and 2000 IU/day (10.24 ± 5.65 ng/ml). Vitamin D toxicity was observed in one patient who received 200000 IU stat of vitamin D. The frequency of VDD following the supplementation was 5.7%. Education status, duration of sun exposure and use of sunblock was substantially associated with vitamin D sufficiency in the current study. CONCLUSION:Our findings underscore the high proportion of VDD among pregnant women in Pakistan. Maternal vitamin D supplementation substantially improved the levels of 25(OH)D. Of three used regimens, the dose of 5000 IU/day is considered safe and equally effective as of 200000 IU stat. Since pregnancy is a time of tremendous growth and physiological changes for mother and her developing fetus with lifelong implications for the child, gestational vitamin D supplementation should be considered to ensure the optimal vitamin D accrual in pregnant women. This study generates the hypothesis that vitamin D supplementation at a dose of 5000 IU/day during pregnancy is superior to the other regimens. However, well-controlled randomized trials are needed to confirm these findings.
Project description:BackgroundPregnancy is a critical period for both woman and baby from a nutritional perspective. Nutritional education is considered an important tool for promoting a healthy lifestyle, but has not been studied as a determinant for maternal use of supplements during pregnancy, especially in Romania, where evidence about pregnancy and nutrition is scarce. This study aimed to evaluate the relationship between nutritional knowledge and the use of folic acid, iron and multivitamin supplements during pregnancy and to assess the influence of socio-demographic factors and prenatal care.MethodsWe conducted a cross-sectional study on a sample of 400 pregnant women admitted to the Cuza-Vodă Obstetrics and Gynaecology Clinical Hospital in Iaşi, Romania, during August-September 2010. We collected self-reported data regarding socio-demographic characteristics, number of prenatal check-ups and the use of folic acid, iron and multivitamin supplements during pregnancy. We assessed nutritional knowledge using a standardized questionnaire divided into three sections: general nutritional recommendations for pregnant women; the roles of nutrients; and sources of nutrients. We used logistic regression to analyse the associations between these factors.ResultsThe prevalence of the use of supplements during pregnancy was 48% for folic acid, 45.3% for iron and 68% for multivitamins. Above-average nutritional knowledge was independently associated with the use of folic acid (aOR, 4.7; 95% CI, 1.6-13.8), iron (aOR, 2.6; 95% CI, 1.2-5.7) and multivitamins (aOR, 2.8; 95% CI, 1.2-6.8). The use of folic acid was independently associated with a higher level of formal education (aOR, 5.2; 95% CI, 2.1-12.8) and an early start in prenatal care (aOR, 3.4; 95% CI, 1.0-11.1). Women with a higher education (aOR, 2.3; 95% CI, 1.1-4.9), more than 10 prenatal visits (aOR, 7.2; 95% CI, 3.4-15.0) and those who received advice on breastfeeding (aOR, 2.0; 95% CI, 1.1-3.5) were more likely to use iron during pregnancy. Similar results were found when analysing the contributing factors for the use of multivitamins: more than 12 years of schooling (aOR, 3.4; 95% CI, 1.4-7.9) and appropriate prenatal care (aOR, 9.4; 95% CI, 4.5-19.5).ConclusionsLevel of nutritional knowledge has a strong independent association with the use of supplements during pregnancy.