Association Between Vitamin D Supplementation During Pregnancy and Offspring Growth, Morbidity, and Mortality: A Systematic Review and Meta-analysis

Vitamin D and Multiple Health Outcomes: An Umbrella Review of Observational Studies, Randomized Controlled Trials, and Mendelian Randomization Studies

Observational studies, randomized controlled trials (RCTs), and Mendelian randomization (MR) studies have yielded inconsistent results on the associations of vitamin D concentrations with multiple health outcomes. In the present umbrella review we aimed to evaluate the effects of low vitamin D concentrations and vitamin D supplementation on multiple health outcomes. We summarized current evidence obtained from meta-analyses of observational studies that examined associations between vitamin D concentrations and multiple health outcomes, meta-analyses of RCTs that investigated the effect of vitamin D supplementation on multiple health outcomes, and MR studies that explored the causal associations of vitamin D concentrations with various diseases (international prospective register of systematic reviews PROSPERO registration number CRD42018091434). A total of 296 meta-analyses of observational studies comprising 111 unique outcomes, 139 meta-analyses of RCTs comprising 46 unique outcomes, and 73 MR studies comprising 43 unique outcomes were included in the present umbrella review. Twenty-eight disease outcomes were identified by both meta-analyses of observational studies and MR studies. Seventeen of these reported disease outcomes had consistent results, demonstrating that lower concentrations of vitamin D were associated with a higher risk for all-cause mortality, Alzheimer's disease, hypertension, schizophrenia, and type 2 diabetes. The combinations of consistent evidence obtained by meta-analyses of observational studies and MR studies together with meta-analyses of RCTs showed that vitamin D supplementation was associated with a decreased risk for all-cause mortality but not associated with the risk for Alzheimer's disease, hypertension, schizophrenia, or type 2 diabetes. The results indicated that vitamin D supplementation is a promising strategy with long-term preventive effects on multiple chronic diseases and thus has the potential to decrease all-cause mortality. However, the current vitamin D supplementation strategy might not be an efficient intervention approach for these diseases, suggesting that new strategies are highly needed to improve the intervention outcomes.

Maternal Vit D supplementation in AMA mice and the role of Vit D/VDR signaling in the offspring's cognition

OBJECTIVE

To explore the molecular mechanism underlying the effect of maternal vitamin D (Vit D) supplementation before pregnancy in advanced maternal age (AMA) mice on the offspring's cognitive function.

METHODS

Thirty-two-week-old female mice either received 10 IU/g body weight vitamin D₃ dissolved in 200 μl corn oil (32W+VD group), or 200 μl corn oil (32W group) per day for one week. Another group of eight-week-old female mice received the same amount of corn oil as 32W group was set as normal reproductive age control (8W group). Then the three groups of female mice were mating with ten-week-old male mice at 2:1 ratio, the offspring were weaned at the age of 3 weeks and housed until the age of 6 weeks. Vit D metabolites and enzymes involved in Vit D metabolism were measured in both mothers and their offspring. Vit D receptor (VDR) and synaptic markers were determined in the offspring hippocampus. Vit D response elements in HIF-1α promoter were predicted, and VDR transcriptional target genes and related signaling molecules were also detected.

RESULTS

Vit D intervention markedly improved the serum 1,25 dihydroxy vitamin D₃ (1,25(OH)₂D₃) concentration in early pregnancy, middle pregnancy and late pregnancy stages in AMA mice. The hippocampal 1,25(OH)₂D₃ levels in the offspring showed the similar pattern. Subsequently, the expression of Cyp27b1, the gene encoding enzyme that converts 25(OH)D₃ to 1,25(OH)₂D₃, in the hippocampus of the offspring from AMA mice was significantly lower than that of the offspring from normal female mice, and was restored by Vit D supplementation. VDR (Vit D receptor), which mediates the cellular actions of active 1,25(OH)₂D₃, was also rescued by Vit D supplementation, especially in dentate gyrus (DG) region of hippocampus. Concurrently, the synaptic markers NR1, NR2A, and PSD-93 in the hippocampus were reversed in 32W+VD group. Finally, we found that Vit D supplementation may affect PI3K-AKT, PLC-ERK1/2, and p38-MAPK signaling molecules by mediating HIF1α expression via VDR.

CONCLUSION

Our findings highlight the biological significance of maternal Vit D supplementation before pregnancy on Vit D metabolism, and signaling molecules in the offspring, underlying the potential mechanism of the cognitive impairment in the offspring born to AMA mice.

Meta-analyses of maternal exposure to atmospheric particulate matter and risk of congenital anomalies in offspring

Congenital anomalies are the main causes of infant death and disability. Previous studies have suggested that maternal exposure to particulate matter is related to congenital malformation. However, the conclusions of this study remain controversial. Hence, meta-analyses were performed to assess the relationship between maternal exposure to particulate matter and the risk of congenital anomalies. The Medline, Embase, and Web of Science databases were systemically searched from inception until August 2020 to find articles related to birth defects and particulate matter. The pooled risk estimated for the combination of pollution outcomes was calculated for each study by performing fixed effects or random effects models. The existence of heterogeneity and publication bias in relevant studies was also examined. Thirty studies were included in the analysis. A statistically increased summary risk valuation was found. PM₁₀ exposure was associated with an increased risk of congenital heart disease, neural tube defects, and cleft lip with or without cleft palate (OR per 10 μg/m³ = 1.05, 95% CI, 1.03-1.07; OR per 10 μg/m³ = 1.04, 95% CI, 1.01-1.06; OR per 10 μg/m³ = 1.03, 95% CI, 1.01-1.06). Maternal exposure to particulate matter might be associated with an increased risk of congenital anomalies. Our results indicate the dangers of particulate matter exposure on fetal development and the importance of protection against exposure to such particles during pregnancy. The schematic representation of the association between maternal exposure to PM_2.5/PM₁₀ and congenital anomalies in offspring, and geographic distribution of the included reports in the meta-analyses.

Maternal-focused interventions to improve infant growth and nutritional status in low-middle income countries: A systematic review of reviews

BACKGROUND

Small and nutritionally at-risk infants under 6 months (<6m) are a vulnerable group at increased risk of mortality, morbidity, poor growth and sub-optimal development. Current national and international (World Health Organization) management guidelines focus mainly on infants' needs, yet growing evidence suggests that maternal factors also influence infant outcomes. We aimed to inform future guidelines by exploring the impacts of maternal-focused interventions on infant feeding and growth.

METHODS

We conducted a systematic review of reviews published since 2008 (PROSPERO, register number CRD 42019141724). We explored five databases and a wide variety of maternal-focused interventions based in low- and middle-income countries. Infant outcomes of interest included anthropometric status, birthweight, infant mortality, breastfeeding and complementary feeding practices. Given heterogenous interventions, we present a narrative synthesis of the extracted data.

RESULTS

We included a total of 55 systematic reviews. Numerous maternal interventions were effective in improving infant growth or feeding outcomes. These included breastfeeding promotion, education, support and counselling interventions. Maternal mental health, while under-researched, showed potential to positively impact infant growth. There was also some evidence for a positive impact of: women's empowerment, m-health technologies, conditional cash transfers, water, sanitation and hygiene and agricultural interventions. Effectiveness was increased when implemented as part of a multi-sectoral program. Antenatal supplementation with macronutrient, multiple micronutrients, Vitamin D, zinc, iron folic acid and possibly calcium, iodine and B12 in deficient women, improved birth outcomes. In contrast, evidence for postnatal supplementation was limited as was evidence directly focusing on small and nutritionally at-risk infants; most reviews focused on the prevention of growth faltering.

CONCLUSION

Our findings suggest sufficient evidence to justify greater inclusion of mothers in more holistic packages of care for small and nutritionally at-risk infants aged <6m. Context specific approaches are likely needed to support mother-infant dyads and ensure infants survive and thrive.

Vitamin D supplementation during pregnancy: an overview

PURPOSE OF REVIEW

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.

RECENT FINDINGS

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.

SUMMARY

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.

Vitamin D supplementation in mice with advanced maternal age and cognitive function of the offspring

To investigate the effects of vitamin D supplementation before pregnancy on the offspring's cognitive function in mice with advanced maternal age (AMA). Thirty-two-week-old female mice were randomly allocated into two groups: the 32 W+VD group (receiving 10 IU/g body weight vitamin D₃ dissolved in 200 μl corn oil per day), and the 32 W group (receiving 200 μl corn oil per day) for one week before mating with ten-week-old male mice. Another group of eight-week-old female mice was given 200 μl corn oil for the same period of time and set as normal childbearing age controls (8 W group). The pregnancy outcomes were recorded and the offspring at the age of 6 weeks were subjected to behavioral tests. Finally, the expression level and distribution of neural cell markers in the offspring's hippocampus were detected by immunofluorescence. Mice with AMA had higher risk of adverse pregnancy outcome, smaller litter size, and offspring development. Vitamin D supplementation in mice with AMA promoted offspring development. AMA and maternal vitamin D supplementation before pregnancy did not change the anxiety and depression of young adult offspring. AMA impaired spatial learning and memory function of offspring while vitamin D supplementation before pregnancy rescued the impairment. AMA decreased NEFH (neurofilament protein) and MAP2 (microtubule binding protein) expression in offspring hippocampus, but vitamin D supplementation before pregnancy promoted NEFH and MAP2. Vitamin D supplementation before pregnancy can rescue the impaired learning and memory in offspring born to AMA mice. Our results highlight the significant impact of maternal vitamin D supplementation on the cognitive function of offspring.

Nutrition in Pregnancy: A Comparative Review of Major Guidelines

Importance

Nutrition patterns in pregnancy play a decisive role in the well-being of the mother and the fetus.

Objective

The aim of this review was to summarize and compare guidelines and recommendations on nutrition in pregnancy.

Evidence Acquisition

A descriptive review of major guidelines on antenatal nutrition was conducted, including the most recently published guidelines, namely, by the Australian Government Department of Health (2018); the Canadian Nutrition Working Group and Society of Obstetricians and Gynaecologists of Canada (2016); the World Health Organization (2016); the Institute of Obstetricians and Gynaecologists, Royal College of Physicians of Ireland (2016); the International Federation of Gynecology and Obstetrics (2015); the Academy of Nutrition and Dietetics (2014); and the National Institute for Health and Care Excellence (2008).

Results

There is almost universal agreement regarding macronutrient requirements during pregnancy. The WHO, FIGO, and the NICE guidelines make no recommendation on fluid intake. Almost all guidelines state that weight gain during pregnancy should be closely monitored. Folic acid supplementation is universally recommended from the preconception period, but there are controversies regarding other vitamins' supplementation. Multiple micronutrient supplementation could be an option in specific settings according only to the FIGO. Probiotics are not routinely recommended in pregnancy.

Conclusions

There is wide agreement among the reviewed guidelines regarding nutrition in pregnancy, but still there are controversies. Evaluation and classification of influential guidelines can be beneficial for establishing a universal consensus on nutrition during pregnancy, in order to achieve more favorable perinatal outcomes.

Vitamin D: A Pleiotropic Hormone with Possible Psychotropic Activities

BACKGROUND

After the recognition of the efficacy of cod-liver oil in rickets at the end of the eighteenth century, and the isolation and synthesis of the liposoluble vitamin D in 1931, its mode of actions and functions were deeply explored. Biochemical studies permitted to identify five forms of vitamin D, called D1, D2, D3, D4 and D5, differing in ultrastructural conformation and origin, with vitamin D2 (ergocalciferol) and D3 (cholecalciferol) representing the active forms. In the last decades especially, a constantly increasing bulk of data highlighted how vitamin D could regulate several activities and processes.

AIMS

The aim of the present paper was to review and comment on the literature on vitamin D, with a focus on its possible role in the pathophysiology of neuropsychiatric disorders.

DISCUSSION

Available literature indicates that vitamin D regulates a variety of processes in humans and in the central nervous system. Vitamin D deficiency is associated with an enhanced pro-inflammatory state, and formation of Aβ oligomers that might contribute to the cognitive decline typical of the elderly age and, perhaps, dementia. More in general, vitamin D is supposed to play a crucial role in neuroinflammation processes that are currently hypothesized to be involved in the pathophysiology of different psychiatric disorders, such as major depression, bipolar disorders, obsessive-compulsive disorders and psychosis.

CONCLUSION

It is conceivable that vitamin D supplementation might pave the way towards "natural" treatments of a broad range of neuropsychiatric disorders, or at least be useful to boost response to psychotropic drugs in resistant cases.

[Association of neonatal blood calcium levels with perinatal factors and neonatal urinary calcium levels measured by an intelligent urine test system]

OBJECTIVE

To study the association of neonatal blood calcium levels with perinatal factors and neonatal urinary calcium levels measured by an intelligent urine test system.

METHODS

The medical data of 96 full-term singleton neonates with mild diseases were collected by a cross-sectional survey, who were hospitalized in the Department of Neonatology, The First Affiliated Hospital of Xi'an Jiaotong University, from June to August 2018. Urinary calcium levels measured by an intelligent urine test system, total blood calcium levels, ionized calcium levels, and the mother's calcium and vitamin D supplementation during pregnancy were recorded.

RESULTS

Compared with the group without vitamin D supplementation for the mother (17 neonates), the group with vitamin D supplementation for the mother (79 neonates) had significantly higher levels of total blood calcium and ionized calcium (P < 0.05).The group with both vitamin D and calcium supplementation for the mother (68 neonates) had significantly higher levels of ionized calcium than controls (28 neonate) (P=0.05). There was no significant difference in the levels of total blood calcium and ionized calcium between the group with calcium supplementation for the mother (74 neonates) and the group without calcium supplementation for the mother (22 neonates) (P > 0.05). The hypothermia group (5 neonates) had a significantly lower level of total blood calcium than the normal body temperature group (91 neonates) (P < 0.05). There was a significantly positive correlation between the maternal blood total calcium level and the neonatal blood total calcium and ionized calcium levels (r=0.881 and 0.703 respectively; P < 0.05). The neonatal urinary calcium level measured by the intelligent urine test system was significantly correlated with the blood ionized calcium level (r=0.526, P=0.025).

CONCLUSIONS

Vitamin D supplementation during pregnancy can increase the blood levels of total calcium and ionized calcium in neonates, and calcium supplementation alone cannot increase the blood levels of total calcium or ionized calcium in neonates. Hypothermia in neonates might cause the reduction in blood calcium levels. The urinary calcium level measured by the intelligent urine test system is positively correlated with the blood level of ionized calcium.

[Association of neonatal blood calcium levels with perinatal factors and neonatal urinary calcium levels measured by an intelligent urine test system]

OBJECTIVE

To study the association of neonatal blood calcium levels with perinatal factors and neonatal urinary calcium levels measured by an intelligent urine test system.

METHODS

The medical data of 96 full-term singleton neonates with mild diseases were collected by a cross-sectional survey, who were hospitalized in the Department of Neonatology, The First Affiliated Hospital of Xi'an Jiaotong University, from June to August 2018. Urinary calcium levels measured by an intelligent urine test system, total blood calcium levels, ionized calcium levels, and the mother's calcium and vitamin D supplementation during pregnancy were recorded.

RESULTS

Compared with the group without vitamin D supplementation for the mother (17 neonates), the group with vitamin D supplementation for the mother (79 neonates) had significantly higher levels of total blood calcium and ionized calcium (P < 0.05).The group with both vitamin D and calcium supplementation for the mother (68 neonates) had significantly higher levels of ionized calcium than controls (28 neonate) (P=0.05). There was no significant difference in the levels of total blood calcium and ionized calcium between the group with calcium supplementation for the mother (74 neonates) and the group without calcium supplementation for the mother (22 neonates) (P > 0.05). The hypothermia group (5 neonates) had a significantly lower level of total blood calcium than the normal body temperature group (91 neonates) (P < 0.05). There was a significantly positive correlation between the maternal blood total calcium level and the neonatal blood total calcium and ionized calcium levels (r=0.881 and 0.703 respectively; P < 0.05). The neonatal urinary calcium level measured by the intelligent urine test system was significantly correlated with the blood ionized calcium level (r=0.526, P=0.025).

CONCLUSIONS

Vitamin D supplementation during pregnancy can increase the blood levels of total calcium and ionized calcium in neonates, and calcium supplementation alone cannot increase the blood levels of total calcium or ionized calcium in neonates. Hypothermia in neonates might cause the reduction in blood calcium levels. The urinary calcium level measured by the intelligent urine test system is positively correlated with the blood level of ionized calcium.

Associations between maternal circulating 25-hydroxyvitamin D concentration and birth outcomes-Mode of delivery and episiotomy rate: A prospective cohort study

AIM

The objective of this study was to evaluate associations between maternal concentrations of 25-hydroxyvitamin D (25(OHD)) and birth outcomes: mode of delivery and episiotomy rate.

DESIGN AND METHODS

One hundred and seventeen pregnant women were enrolled in an observational, longitudinal, prospective cohort study. Multivariable linear regression analyses were performed to assess relationships between maternal 25(OHD) concentrations and mode of delivery. To account for systematic temporal variation in 25(OHD), a cosinor model to the data was fitted.

RESULTS

No significant statistical associations were found between adjusted maternal 25(OHD) concentrations and risk of eutocic vaginal delivery, instrumented delivery (OR 1.05 [95% CI: 0.97-1.13]), primary Caesarean section (OR 0.99 [95% CI: 0.88-1.11]) or Caesarean section for any other causes (OR 1.04 [95% CI: 0.95-1.14]). High 25(OHD) levels tended to show a protective effect on performance of episiotomy, without reaching statistical significance (OR 0.36 [95% CI: 0.09, 1.37]).

The Influence of Disease Activity on Pregnancy Outcomes in Women With Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

Robust evidence regarding the impact of disease activity on pregnancy outcomes in women with inflammatory bowel disease [IBD] is crucial for both clinicians and patients in preparing a birth plan. We sought to perform a systematic review and meta-analysis to assess the pooled influences of disease activity on pregnancy outcomes in women with IBD.

METHODS

We searched MEDLINE, EMBASE and the COCHRANE library to identify articles comparing pregnancy outcomes between active and inactive IBD at the time of conception or during pregnancy. A meta-analysis was performed using a random-effects model to pool estimates and report odds ratios [ORs].

RESULTS

A total of 28 studies were identified as eligible for the meta-analysis. In women with active IBD, the pooled ORs for low birth weight [LBW], preterm birth, small for gestational age [SGA], spontaneous abortion and stillbirths were respectively 3.81 (95% confidence interval [CI] 1.81-8.02), 2.42 [95% CI 1.74-3.35], 1.48 [95% CI 1.19-1.85], 1.87 [95% CI 1.17-3.0] and 2.27 [95% CI 1.03-5.04] compared to women with inactive IBD. In the subgroup analysis based on disease type, women with active ulcerative colitis had an increased risk of LBW, preterm birth and spontaneous abortion. Women with active Crohn's disease had a higher risk of preterm birth, SGA and spontaneous abortion.

CONCLUSIONS

Active IBD during the periconception period and pregnancy is associated with an increased risk of adverse pregnancy outcomes. Our data suggest that pregnancy should be planned when the disease is quiescent, and continuous disease control is important even during pregnancy.

The Effects of Vitamin D Supplementation During Infancy on Growth During the First 2 Years of Life

CONTEXT

The relationship between maternal and infant vitamin D and early childhood growth remains inadequately understood.

OBJECTIVE

This work aimed to investigate how maternal and child 25-hydroxyvitamin D (25[OH]D) and vitamin D supplementation affect growth during the first 2 years of life.

METHODS

A randomized, double-blinded, single-center intervention study was conducted from pregnancy until offspring age 2 years. Altogether 812 term-born children with complete data were recruited at a maternity hospital. Children received daily vitamin D3 supplementation of 10 μg (group 10) or 30 μg (group 30) from age 2 weeks to 2 years. Anthropometry and growth rate were measured at age 1 and 2 years.

RESULTS

Toddlers born to mothers with pregnancy 25(OH)D greater than 125 nmol/L were at 2 years lighter and thinner than the reference group with 25(OH)D of 50 to 74.9 nmol/L (P < .010). Mean 2-year 25(OH)D concentrations were 87 nmol/L in group 10 and 118 nmol/L in group 30 (P < .001). When group 30 was compared with group 10, difference in body size was not statistically significant (P > .053), but group 30 had slower growth in length and head circumference between 6 months and 1 year (P < .047), and more rapid growth in weight and length-adjusted weight between 1 and 2 years (P < .043). Toddlers in the highest quartile of 25(OH)D (> 121 nmol/L) were shorter (mean difference 0.2 SD score [SDS], P = .021), lighter (mean difference 0.4 SDS, P = .001), and thinner (in length-adjusted weight) (mean difference 0.4 SDS, P = .003) compared with the lowest quartile (< 81.2 nmol/L).

CONCLUSION

Vitamin D and early childhood growth may have an inverse U-shaped relationship.

Effect of Vitamin D Supplementation in Early Life on Children's Growth and Body Composition: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Vitamin D deficiency during pregnancy or infancy is associated with adverse growth in children. No systematic review has been conducted to summarize available evidence on the effect of vitamin D supplementation in pregnancy and infancy on growth and body composition in children. Objective: We aim to summarize the available evidence on the effect of vitamin D supplementation in pregnancy and infancy on child growth and body composition. Method: A systematic review and meta-analysis were performed on the effects of vitamin D supplementation during early life on children’s growth and body composition (bone, lean and fat). A literature search of randomized controlled trials (RCTs) was conducted to identify relevant studies on the effects of vitamin D supplementation during pregnancy and infancy on children’s body composition (bone, lean and fat) in PubMed, EMBASE and Cochrane Library from inception to 31 December 2020. A Cochrane Risk Assessment Tool was used for quality assessment. The comparison was vitamin D supplementation vs. placebo or standard care. Random-effects and fixed-effect meta-analyses were conducted. The effects are presented as mean differences (MDs) or risk ratios (RRs) with 95% confidence intervals (CIs). Results: A total of 3960 participants from eleven randomized controlled trials were eligible for inclusion. Vitamin D supplementation during pregnancy was associated with higher triceps skinfold thickness (mm) (MD 0.33, 95% CI, 0.12, 0.54; I² = 34%) in neonates. Vitamin D supplementation during pregnancy or infancy was associated with significantly increased length for age z-score in infants at 1 year of age (MD 0.29, 95% CI, 0.03, 0.54; I² = 0%), and was associated with lower body mass index (BMI) (kg/m²) (MD −0.19, 95% CI −0.34, −0.04; I² = 0%) and body mass index z-score (BMIZ) (MD −0.12, 95% CI −0.21, −0.04; I² = 0%) in offspring at 3–6 years of age. Vitamin D supplementation during early life was not observed to be associated with children’s bone, lean or fat mass. Conclusion: Vitamin D supplementation during pregnancy or infancy may be associated with reduced adiposity in childhood. Further large clinical trials of the effects of vitamin D supplementation on childhood body composition are warranted.

Does the High Prevalence of Vitamin D Deficiency in African Americans Contribute to Health Disparities?

African Americans have higher incidence of, and mortality from, many health-related problems than European Americans. They also have a 15 to 20-fold higher prevalence of severe vitamin D deficiency. Here we summarize evidence that: (i) this health disparity is partly due to insufficient vitamin D production, caused by melanin in the skin blocking the UVB solar radiation necessary for its synthesis; (ii) the vitamin D insufficiency is exacerbated at high latitudes because of the combination of dark skin color with lower UVB radiation levels; and (iii) the health of individuals with dark skin can be markedly improved by correcting deficiency and achieving an optimal vitamin D status, as could be obtained by supplementation and/or fortification. Moderate-to-strong evidence exists that high 25-hydroxyvitamin D levels and/or vitamin D supplementation reduces risk for many adverse health outcomes including all-cause mortality rate, adverse pregnancy and birth outcomes, cancer, diabetes mellitus, Alzheimer's disease and dementia, multiple sclerosis, acute respiratory tract infections, COVID-19, asthma exacerbations, rickets, and osteomalacia. We suggest that people with low vitamin D status, which would include most people with dark skin living at high latitudes, along with their health care provider, consider taking vitamin D3 supplements to raise serum 25-hydroxyvitamin D levels to 30 ng/mL (75 nmol/L) or possibly higher.

Vitamin D Concentrations at Term Do Not Differ in Newborns and Their Mothers with and without Polycystic Ovary Syndrome

Studies suggest that non-pregnant women with polycystic ovary syndrome (PCOS) may be at elevated risk of 25 hydroxyvitamin D (25(OH)D) deficiency. Furthermore, there is evidence suggesting that 25(OH)D may also play an important role during pregnancy. Data regarding 25(OH)D deficiency during pregnancy in PCOS patients and its association with perinatal outcome is scarce. The aim of the study was to investigate whether mothers with and without PCOS have different 25(OH)D levels at term, how maternal 25(OH)D levels are reflected in their offspring, and if 25(OH)D levels are associated with an adverse perinatal outcome. Therefore, we performed a cross-sectional observational study and included 79 women with PCOS according to the ESHRE/ASRM 2003 definition and 354 women without PCOS and an ongoing pregnancy ≥ 37 + 0 weeks of gestation who gave birth in our institution between March 2013 and December 2015. Maternal serum and cord blood 25(OH)D levels were analyzed at the day of delivery. Maternal 25(OH)D levels did not differ significantly in women with PCOS and without PCOS (p = 0.998), nor did the 25(OH)D levels of their respective offspring (p = 0.692). 25(OH)D deficiency (<20 ng/mL) was found in 26.9% and 22.5% of women with and without PCOS (p = 0.430). There was a strong positive correlation between maternal and neonatal 25(OH)D levels in both investigated groups (r ≥ 0.79, p < 0.001). Linear regression estimates of cord blood 25(OH)D levels are about 77% of serum 25(OH)D concentrations of the mother. Compared to healthy controls, the risk for maternal complications was increased in PCOS women (48% vs. 65%; p = 0.009), while there was no significant difference in neonatal complications (22% and 22%; p = 1.0). However, 25(OH)D levels were similar between mothers and infants with and without perinatal complications. Although the share of women and infants with 25(OH)D deficiency was high in women with PCOS and without PCOS, it seems that the incidence of adverse perinatal outcome was not affected. The long-term consequences for mothers and infants with a 25(OH)D deficiency have to be investigated in future studies.

Effects of Maternal Nutritional Supplements and Dietary Interventions on Placental Complications: An Umbrella Review, Meta-Analysis and Evidence Map

The placenta is a vital, multi-functional organ that acts as an interface between maternal and fetal circulation during pregnancy. Nutritional deficiencies during pregnancy alter placental development and function, leading to adverse pregnancy outcomes, such as pre-eclampsia, infants with small for gestational age and low birthweight, preterm birth, stillbirths and maternal mortality. Maternal nutritional supplementation may help to mitigate the risks, but the evidence base is difficult to navigate. The primary purpose of this umbrella review is to map the evidence on the effects of maternal nutritional supplements and dietary interventions on pregnancy outcomes related to placental disorders and maternal mortality. A systematic search was performed on seven electronic databases, the PROSPERO register and references lists of identified papers. The results were screened in a three-stage process based on title, abstract and full-text by two independent reviewers. Randomized controlled trial meta-analyses on the efficacy of maternal nutritional supplements or dietary interventions were included. There were 91 meta-analyses included, covering 23 types of supplements and three types of dietary interventions. We found evidence that supports supplementary vitamin D and/or calcium, omega-3, multiple micronutrients, lipid-based nutrients, and balanced protein energy in reducing the risks of adverse maternal and fetal health outcomes. However, these findings are limited by poor quality of evidence. Nutrient combinations show promise and support a paradigm shift to maternal dietary balance, rather than single micronutrient deficiencies, to improve maternal and fetal health. The review is registered at PROSPERO (CRD42020160887).

The role of serum levels of vitamin D in children's muscle strength: A systematic review

This review aims to investigate the different levels of vitamin D and its role in muscle strength in healthy children and non-athletes. A search conducted in three databases (PubMed, Scopus, and Psycinfo) resulted in 655 articles, which were systematically analyzed and selected based on the following criteria: (a) original cross-sectional studies and clinical trials; (b) healthy children aged 5-11 years; (c) no language restriction or year of publication; and (d) studies that assessed the possible relationship between vitamin D levels and muscle strength. Six studies were included because they met all the inclusion criteria. According to the findings of this review, factors such as sex, skin color, and vitamin D supplementation early in life modulate the levels of vitamin D in the body, and there is a relationship between muscle strength and vitamin D levels. Interestingly, vitamin D supplementation is not always significantly associated with increased muscle grip strength. However, there is a scarcity of studies that aim to analyze the possible effects of different levels of vitamin D on muscle function and neuromuscular variables in physically inactive children and non-athletes without previously diagnosed disease. Further studies are warranted in the future to address the gap in the literature.

Effects of vitamin D on neonatal sepsis: A systematic review and meta-analysis

Vitamin D deficiency is a major public health concern of pregnant women and neonates worldwide, affecting more than half of neonates. Studies report inconsistent and inconclusive effects of vitamin D treatment on neonatal sepsis. This study aimed to provide conclusive evidence regarding the effect of maternal and cord blood vitamin D levels on neonatal sepsis. Data were retrieved from the electronic database (Web of Science, Scopus, CINAHL [EBSCOhost], ProQuest, EMBASE [Ovid], PubMed, Emcare, MEDLINE [Ovid], and gray literature sources [World cat, Mednar, Google scholar and Google]). Joanna Briggs Institute quality assessment tool was utilized for quality assessment while analysis was performed using Open Meta-analyst, Comprehensive Meta-analysis version 3.3.070, and Review Manager version 5.3 software. From the 18 studies included in the study, the overall prevalence of vitamin D deficiency among neonates was 61% (95% CI: 44.3, 77.7); 79.4% (95% CI: 71.6, 87.3) of neonates with sepsis were vitamin D deficient as were 43.7% (23.4, 63.9) of sepsis-free neonates. Neonates born from mothers with low vitamin D levels were at greater risk of developing neonatal sepsis with a weighed mean difference of -8.57 ng/ml (95% CI: -13.09, -4.05). Similarly, neonates with low cord vitamin D levels were at risk for neonatal sepsis with a mean difference of -8.78 ng/ml (95% CI:-11.58, -5.99). The incidence of EONS in full-term newborns was significantly associated with low maternal and cord blood vitamin D levels with weighed mean differences of -11.55ng/ml (95% CI: -17.63, -5.46) & -11.59 ng/ml (95% CI:-16.65, -6.53), respectively. Low levels of vitamin D both in the cord blood and maternal blood were significantly associated with neonatal sepsis. Hence, vitamin D supplementation for pregnant women and newborns could decrease neonatal sepsis.

[Vitamin D and pregnancy: current state of the problem in the central regions of the Russian Federation]

BACKGROUND

It has been proven that vitamin D plays an important role in pregnancy. Deficiency of this element may be associated with the risk of developing gestational diabetes mellitus, preeclampsia, placentar insufficiency, low birth weight and premature birth.

AIMS

To conduct an epidemiological analysis of vitamin D supply in women at different stages of pregnancy, living in Russia.

MATERIALS AND METHODS

We included 1198 pregnant women living in 3 regions of Russia in the observational, multicenter, cross-sectional, continuous study. All pregnant women were tested for serum 25(OH)D levels. We collected biomaterial from August 2018 to December 2019. The end point of the study was the indicator of vitamin D supply in pregnant women and its level depending on the trimester of pregnancy and region of Russia. Statistical analysis included counting and grouping according to vitamin D levels, and calculating the median vitamin D concentration in each region.

RESULTS

We confirmed vitamin D deficiency in all regions. The optimum level of this element is present in less than 7% of women. Insufficiency of this element is present in 20,62% of all women. The largest percentage of them is in a deficit of this element - 46,66%. We found that the lowest rates are in Smolensk, where the median was 12,75 ng/ml. In addition, we found changes in vitamin D concentration: with an increase in gestational age revealed a decrease in its level.

CONCLUSIONS

In our study, we confirmed the presence of a 25(OH)D deficiency in most of the examined pregnant women, which is consistent with international epidemiological data. We should remember about these both at the stage of pre-gravid preparation and at the stage of pregnancy itself in order to achieve the optimal level of vitamin D.

High-Dose Vitamin D Supplementation in Pregnancy and Neurodevelopment in Childhood: A Prespecified Secondary Analysis of a Randomized Clinical Trial

IMPORTANCE

Observational studies have reported an association between high maternal vitamin D levels and improved neurodevelopment in offspring, but no randomized clinical trial (RCT) has investigated these observations.

OBJECTIVE

To determine whether high-dose vitamin D supplementation during pregnancy improves offspring neurodevelopment from birth to age 6 years.

DESIGN, SETTING, AND PARTICIPANTS

This prespecified secondary analysis of a double-blinded, placebo-controlled RCT of high-dose vitamin D3 supplementation vs standard dose during the third trimester of pregnancy was conducted in the unselected prospective mother-child birth cohort at a single-center research unit in Denmark as part of the Copenhagen Prospective Studies on Asthma in Childhood 2010 (COPSAC-2010). Participants included pregnant women; women with vitamin D intake greater than 600 IU/d or an endocrine, heart, or kidney disorder, and those who did not speak Danish fluently were excluded. Neurodevelopmental assessments for offspring of these women were performed at ages 0 to 6 years. Children born prematurely (gestational week <37), with low birth weight (<2500 g), or with a neurological disease affecting neurodevelopment were excluded. Data were analyzed from August 2019 to February 2020.

INTERVENTIONS

High-dose (ie, 2800 IU/d) vs standard dose (ie, 400 IU/d) vitamin D3 supplementation from pregnancy week 24 until 1 week after birth.

MAIN OUTCOMES AND MEASURES

The primary outcome of interest was cognitive development assessed at 2.5 years using the Bayley Scales of Infant and Toddler Development. Other neurodevelopmental outcomes included age of motor milestone achievement (Denver Developmental Index and World Health Organization milestone registration), language development (MacArthur-Bates Communicative Development Inventories), general neurodevelopment at age 3 years (Ages and Stages Questionnaire), and emotional and behavioral problems at age 6 years (Strengths and Difficulties Questionnaire).

RESULTS

Among 623 women randomized, 315 were randomized to high-dose vitamin D3 and 308 were randomized to standard dose placebo. A total of 551 children were evaluated from birth to age 6 years, (282 [51.2%] boys; 528 [95.8%] White), with 277 children in the high-dose vitamin D3 group and 274 children in the standard dose group. There was no effect of the high-dose compared with standard dose of vitamin D3 supplementation during pregnancy on offspring achievement of motor milestones (β = 0.08 [95% CI, -0.26 to 0.43]; P = .64), cognitive development (score difference: 0.34 [95% CI, -1.32 to 1.99]; P = .70), general neurodevelopment (median [IQR] communication score: 50 [50-55] vs 50 [50-55]; P = .62), or emotional and behavioral problems (odds ratio, 0.76 [95% CI, 0.53 to 1.09]; P = .14). There was no effect on language development expressed by the word production at 1 year (median [IQR], 2 [0-6] words vs 3 [1-6] words; P = .16), although a decreased word production was apparent at 2 years in children in the high-dose vitamin D3 group (median [IQR], 232 [113-346] words vs 253 [149-382.5] words; P = .02).

CONCLUSIONS AND RELEVANCE

In this prespecified secondary analysis of an RCT, maternal high-dose vitamin D3 supplementation during the third trimester of pregnancy did not improve neurodevelopmental outcomes in the offspring during the first 6 years of life. These findings contribute essential information clarifying the effects of prenatal exposure to vitamin D on neurodevelopment in childhood.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00856947.

Early-Life Effects of Vitamin D: A Focus on Pregnancy and Lactation

Vitamin D is an endocrine regulator of calcium and bone metabolism. Yet, its effects include other systems, such as innate and adaptive immunity. Unique to pregnancy, circulating 1,25-dihydroxyvitamin D (1,25[OH]2D) increases early on to concentrations that are 2-3 times prepregnant values. At no other time during the lifecycle is the conversion of 25-hydroxyvitamin D (25[OH]D) to 1,25(OH)2D directly related and optimized at ≥100 nmol/L. Vitamin D deficiency appears to affect pregnancy outcomes, yet randomized controlled trials of vitamin D supplementation achieve mixed results depending on when supplementation is initiated during pregnancy, the dose and dosing interval, and the degree of deficiency at the onset of pregnancy. Analysis of trials on an intention-to-treat basis as opposed to the use of 25(OH)D as the intermediary biomarker of vitamin D metabolism yields differing results, with treatment effects often noted only in the most deficient women. Immediately after delivery, maternal circulating 1,25(OH)2D concentrations return to prepregnancy baseline, at a time when a breastfeeding woman has increased demands of calcium, beyond what was needed during the last trimester of pregnancy, making one question why 1,25(OH)2D increases so significantly during pregnancy. Is it to serve as an immune modulator? The vitamin D content of mother's milk is directly related to maternal vitamin D status, and if a woman was deficient during pregnancy, her milk will be deficient unless she is taking higher doses of vitamin D. Because of this relative "deficiency," there is a recommendation that all breastfed infants receive 400 IU vitamin D3/day starting a few days after birth. The alternative - maternal supplementation with 6,400 IU vitamin D3/day, effective in safely raising maternal circulating vitamin D, that of her breast milk, and effective in achieving sufficiency in her recipient breastfeeding infant - remains a viable option. Additional research is needed to understand vitamin D's influence on pregnancy health and the effect of maternal supplementation on breast milk's immune signaling.

Understanding the Biological Activities of Vitamin D in Type 1 Neurofibromatosis: New Insights into Disease Pathogenesis and Therapeutic Design

Vitamin D is a fat-soluble steroid hormone playing a pivotal role in calcium and phosphate homeostasis as well as in bone health. Vitamin D levels are not exclusively dependent on food intake. Indeed, the endogenous production-occurring in the skin and dependent on sun exposure-contributes to the majority amount of vitamin D present in the body. Since vitamin D receptors (VDRs) are ubiquitous and drive the expression of hundreds of genes, the interest in vitamin D has tremendously grown and its role in different diseases has been extensively studied. Several investigations indicated that vitamin D action extends far beyond bone health and calcium metabolism, showing broad effects on a variety of critical illnesses, including cancer, infections, cardiovascular and autoimmune diseases. Epidemiological studies indicated that low circulating vitamin D levels inversely correlate with cutaneous manifestations and bone abnormalities, clinical hallmarks of neurofibromatosis type 1 (NF1). NF1 is an autosomal dominant tumour predisposition syndrome causing significant pain and morbidity, for which limited treatment options are available. In this context, vitamin D or its analogues have been used to treat both skin and bone lesions in NF1 patients, alone or combined with other therapeutic agents. Here we provide an overview of vitamin D, its characteristic nutritional properties relevant for health benefits and its role in NF1 disorder. We focus on preclinical and clinical studies that demonstrated the clinical correlation between vitamin D status and NF1 disease, thus providing important insights into disease pathogenesis and new opportunities for targeted therapy.

Association between maternal or cord blood concentrations of 25-hydroxycholecalciferol or vitamin D supplementation during pregnancy and the cytokines profile in the umbilical cord blood: Systematic literature review

INTRODUCTION

Evidence suggests that vitamin D suppresses the production of pro-inflammatory cytokines and induces the production of anti-inflammatory cytokines during pregnancy.

OBJECTIVES

To assess, through a systematic literature review, the relationship between maternal or cord blood concentrations of 25-hydroxycholecalciferol (25-OH-D) or vitamin D supplementation during pregnancy and the cytokines profile in the umbilical cord.

METHODS

The following databases were searched: PUBMED, CENTRAL, Web of Science, LILACS, and gray literature, up to July 2020. The search strategy included terms related to the exposure (25-OH-D) and the primary outcome (cytokines). Observational studies and randomized clinical trials were included, measuring cytokines in the umbilical cord blood, or in ex vivo bioassays, and blood concentrations of 25-OH-D, either throughout pregnancy or in the umbilical cord blood. Studies with twin pregnancies, with placental or autoimmune diseases, were excluded. The protocol is registered in PROSPERO (number CRD42019136643).

RESULTS

From 14,605 unique articles identified in the databases, 28 were read in full, and of these, eight met the eligibility criteria, being three randomized clinical trials, and five observational studies. The eight studies showed adequate methodological quality. IL-10 was the most studied cytokine, being reported in seven studies. There were higher concentrations of IL-10 in the umbilical cord of women with 25-OH-D sufficiency in the observational studies. Clinical trials showed mixed results with the use of ex vivo bioassays with several stimulants. Associations with other cytokines were less consistent or absent.

CONCLUSION

25-OH-D status is positively associated with the IL-10 levels of the umbilical cord, in observational studies.

Vitamin D Deficiency in Mexican Pregnant Women: Is Supplementation with ≤400 IU/day Enough?

Controversy remains surrounding vitamin D routine supplementation in healthy pregnancy, and the doses are unclear. The aim of this study was to describe maternal vitamin D status throughout pregnancy in a group of Mexican women and evaluate the effect of frequently prescribed doses of vitamin D3 on longitudinal 25-OH-D concentrations, adjusting for obesity, season, and other factors. We conducted a cohort study (Instituto Nacional de Perinatología-INPer) (2017-2020)) of healthy pregnant women without complications. Pregestational overweight/obesity (body mass index ≥ 25), vitamin D3 supplementation (prescribed by physician; 0-250, 250-400, and >400 IU/day), and serum 25-OH-D concentrations (ELISA) were evaluated in each trimester of pregnancy. Vitamin D deficiency or insufficiency was computed (<20 and <30 ng/mL, respectively). We studied 141 adult women; 58.5% had pregestational obesity or overweight. In the first trimester, 45.8% of the women were supplemented with vitamin D3; 51.4% had vitamin D insufficiency and 37.3%, deficiency. In the third trimester, 75.4% of the women were supplemented, and 20% of them still had deficiency. The final general mixed linear model showed that 25-OH-D significantly increased throughout pregnancy (p < 0.001); the highest increase was observed in the third trimester in women with doses >400 IU/day of vitamin D3 (+4 ng/mL, 95% CI: 1.72-8.11 ng/mL). In winter/autumn, 25-OH-D concentrations were also lower (p ≤ 0.05). In this group of pregnant Mexican women, the prevalence of vitamin D deficiency and insufficiency was high. A higher increase in 25-OH-D concentrations during pregnancy was observed when the women were supplemented with >400 IU/day. Common supplementation doses of 250-400 IU/day were insufficient for achieving an adequate maternal vitamin D status.

Effect of High-Dose vs Standard-Dose Vitamin D Supplementation in Pregnancy on Bone Mineralization in Offspring Until Age 6 Years: A Prespecified Secondary Analysis of a Double-Blinded, Randomized Clinical Trial

IMPORTANCE

Studies suggest an association between maternal vitamin D status during pregnancy and offspring anthropometry and bone mineralization, but investigations are few and with mixed results.

OBJECTIVE

To investigate the effect of a high dose vs standard dose of vitamin D supplementation in pregnancy on anthropometric and bone outcomes until age 6 years in the offspring.

DESIGN, SETTING, AND PARTICIPANTS

A prespecified analysis of a double-blinded, randomized clinical trial in the Copenhagen Prospective Studies on Asthma in Childhood 2010 mother-child cohort that included 623 pregnant mothers and their 584 children. Data were analyzed between January 2019 and September 2019.

INTERVENTIONS

Vitamin D supplementation of 2800 IU/d (high-dose) vs 400 IU/d (standard-dose) from pregnancy week 24 until 1 week after birth.

MAIN OUTCOMES AND MEASURES

Longitudinal anthropometry assessments including length/height, weight, and body mass index until age 6 years and bone mineral content (BMC) and bone mineral density (BMD) at age 3 years and 6 years from dual-energy radiography absorptiometry scans.

RESULTS

At age 6 years, 517 children (89%) completed the clinical follow-up. All participants were Danish and white; 261 were boys and 256 were girls. A mixed-effects model analysis of dual-energy radiography absorptiometry scan outcomes from ages 3 years and 6 years showed that children in the vitamin D vs placebo group had higher whole-body BMC: mean difference adjusted (aMD) for age, sex, height, and weight was 11.5 g (95% CI, 2.3-20.7; P = .01); higher whole-body-less-head BMC aMD was 7.5 g (95% CI, 1.5-13.5; P = .01); and higher head BMD aMD was 0.023 g/cm2 (95% CI, 0.003-0.004; P = .03). The largest effect was in children from vitamin D-insufficient mothers (<30 ng/mL; to convert to nanomoles per liter, multiply by 2.496) and among winter births. In a post hoc analysis, we found borderline lower incidence of fractures in the vitamin D group (n = 23 vs n = 36; incidence rate ratio, 0.62 [95% CI, 0.37-1.05]; P = .08), but no differences in any anthropometric outcomes. Adjustment for a concomitant ω-3 polyunsaturated fatty acids intervention did not change the results.

CONCLUSIONS AND RELEVANCE

High-dose vitamin D supplementation in pregnancy improved offspring bone mineralization through age 6 years compared with the standard dose, suggesting an increased recommended gestational intake, which may influence peak bone mass, fracture risk, and risk of osteoporosis later in life. We found no supplementation effect on anthropometric outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00856947.

Vitamin D Status Increases During Pregnancy and in Response to Vitamin D Supplementation in Rural Gambian Women

BACKGROUND

Vitamin D is important to maternal, fetal, and infant health, but quality data on vitamin D status in low- and middle-income countries and response to cholecalciferol supplementation in pregnancy are sparse.

OBJECTIVE

We characterized vitamin D status and vitamin D metabolite change across pregnancy and in response to cholecalciferol supplementation in rural Gambia.

METHODS

This study was a secondary analysis of samples collected in a 4-arm trial of maternal nutritional supplementation [iron folic acid (FeFol); multiple micronutrients (MMN); protein energy (PE) as lipid-based supplement; PE + MMN]; MMN included 10 μg/d cholecalciferol. Plasma 25-hydroxycholecalciferol [25(OH)D3], 24,25-dihydroxycholecalciferol [24,25(OH)2D3], and C3-epimer-25-hydroxycholecalciferol [3-epi-25(OH)D3] were measured by LC-MS/MS in 863 women [aged 30 ± 7 y (mean ± SD)] in early pregnancy (presupplementation) and late pregnancy, (gestational age 14 ± 3 and 30 ± 1 wk). Changes in 25(OH)D3 and vitamin D metabolite concentrations and associations with pregnancy stage and maternal age and anthropometry were tested.

RESULTS

Early pregnancy 25(OH)D3 concentration was 70 ± 15 nmol/L and increased according to pregnancy stage (82 ± 18 and 87 ± 17 nmol/L in the FeFol and PE-arms) and to cholecalciferol supplementation (95 ± 19 and 90 ± 20 nmol/L in the MMN and PE + MMN-arms) (P < 0.0001). There was no difference between supplemented groups. Early pregnancy 25(OH)D3 was positively associated with maternal age and gestational age. Change in 25(OH)D3 was negatively associated with late pregnancy, but not early pregnancy, triceps skinfold thickness. The pattern of change of 24,25(OH)2D3 mirrored that of 25(OH)D3 and appeared to flatten as pregnancy progressed, whereas 3-epi-25(OH)D3 concentration increased across pregnancy.

CONCLUSION

This study provides important data on the vitamin D status of a large cohort of healthy pregnant women in rural Africa. Without supplementation, vitamin D status increased during pregnancy, demonstrating that pregnancy stage should be considered when assessing vitamin D status. Nutritionally relevant cholecalciferol supplementation further increased vitamin D status. These data are relevant to the development of fortification and supplementation policies in pregnant women in West Africa.

Transcriptome analysis of early pregnancy vitamin D status and spontaneous preterm birth

Background

We conducted a literature review on the studies that investigated the relationship of preterm birth, including spontaneous preterm birth (sPTB), with vitamin D status. Overall, these studies demonstrated that the incidence of sPTB was associated with maternal vitamin D insufficiency in early pregnancy. However, the potential mechanisms and biological pathways are unknown.

Objectives

To investigate early pregnancy gene expression signatures associated with both vitamin D insufficiency and sPTB. We further constructed a network of these gene signatures and identified the common biological pathways involved.

Study design

We conducted peripheral blood transcriptome profiling at 10–18 weeks of gestation in a nested case-control cohort of 24 pregnant women who participated in the Vitamin D Antenatal Asthma Reduction Trial (VDAART). In this cohort, 8 women had spontaneous preterm delivery (21–32 weeks of gestation) and 17 women had vitamin D insufficiency (25-hydroxyvitamin D < 30 ng/mL). We separately identified vitamin D-associated and sPTB gene signatures at 10 to 18 weeks and replicated the overlapping signatures in the mid-pregnancy peripheral blood of an independent cohort with sPTB cases.

Result

At 10–18 weeks of gestation, 146 differentially expressed genes (25 upregulated) were associated with both vitamin D insufficiency and sPTB in the discovery cohort (FDR < 0.05). Of these genes, 43 (25 upregulated) were replicated in the independent cohort of sPTB cases and controls with normal pregnancies (P < 0.05). Functional enrichment and network analyses of the replicated gene signatures suggested several highly connected nodes related to inflammatory and immune responses.

Conclusions

Our gene expression study and network analyses suggest that the dysregulation of immune response pathways due to early pregnancy vitamin D insufficiency may contribute to the pathobiology of sPTB.

Vitamin D supplementation to improve pregnancy and perinatal outcomes: an overview of 42 systematic reviews

OBJECTIVE

To review the evidence to assess effectiveness of vitamin D supplementation during pregnancy and associations of serum vitamin D levels with perinatal outcomes.

DESIGN

Overview of systematic reviews (SRs).

DATA SOURCES

Searches conducted in January 2019: Ovid Medline (1946-), Cochrane Library databases.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Two reviewers independently screened titles and abstracts, and full texts using predefined inclusion criteria: SRs evaluating vitamin D supplementation in pregnant women and/or examining the association between serum vitamin D levels reporting at least one predefined perinatal outcome. Only SRs with high AMSTAR scores were analysed.

DATA EXTRACTION AND SYNTHESIS

Data were extracted independently by one reviewer and checked by a second. Results were assessed for quality independently by two reviewers using GRADE criteria.

RESULTS

Thirteen SRs were included, synthesising evidence from 204 unique primary studies. SRs of randomised controlled trials (RCTs) with the highest level of evidence showed no significant benefit from vitamin D in terms of preterm birth (RR 1.00 (95% CI 0.77, 1.30); high quality), pre-eclampsia (RR 0.91 (0.45, 1.86); low quality), gestational diabetes (RR 0.65 (0.39, 1.08); very low quality), stillbirth (RR 0.75 (0.50, 1.12); high quality), low birth weight (RR 0.74 (0.47, 1.16); low quality), caesarean section (RR 1.02 (0.93, 1.12); high quality). A significant difference was found for small for gestational age (RR 0.72 (0.52, 0.99); low quality). SRs of observational studies showed associations between vitamin D levels and preterm birth (RR 1.19 (1.08, 1.31); moderate quality), pre-eclampsia (RR 1.57 (1.21, 2.03) for 25-hydroxy vitamin D (25 (OH)D)<50 nmol/L subgroup; low quality), gestational diabetes (RR 1.12 (1.02, 1.22) for 25 (OH)D<50 nmol/L and RR 1.09 (1.03, 1.15)<75 nmol/L; moderate quality) and small for gestational age (RR 1.35 (1.18, 1.54)<50 nmol/L; low quality). SRs showed mixed results for associations between vitamin D and low birth weight (very low quality) and caesarean section (very low quality).

CONCLUSION

There is some evidence from SRs of observational studies for associations between vitamin D serum levels and some outcomes; however SRs examining effectiveness from RCTs showed no effect of vitamin D supplementation in pregnancy with the exception of one predefined outcome, which had low quality evidence. Credibility of the evidence in this field is compromised by study limitations (in particular, the possibility of confounding among observational studies), inconsistency, imprecision and potential for reporting and publication biases.

25-Hydroxyvitamin D profiles and maternal bone mass during pregnancy and lactation in Japanese women

Vitamin D deficiency is observed worldwide and represents a health hazard for mothers, infants and elderly persons. We know that many young Japanese women experience vitamin D insufficiency; however, there is a lack of knowledge regarding the serum 25-hydroxyvitamin D [25(OH)D] profile of pregnant Japanese women and of the association between maternal 25(OH)D level and maternal bone mass during pregnancy and lactation. In this longitudinal study, 160 pregnant Japanese women were enrolled; of them, 68 have been followed-up from the first trimester through at least 1 year of breast-feeding. We estimated serum 25(OH)D levels, intact PTH levels, calcaneus quantitative ultrasound (QUS: T score) scores, bone mineral density at the distal one-third of the radius, dietary intakes according to the Food Frequency Questionnaire, and sunlight exposure times. We found that Vitamin D deficiency is prevalent in Japanese women, irrespective of pregnancy or lactation, and our analysis suggested that 25(OH)D levels and BMI in the first trimester were related to the lactating women's bone mass from after delivery to 1 year after delivery.

Comparison of seasonal serum 25-hydroxyvitamin D concentrations among pregnant women in Mongolia and Boston

Adequate vitamin D status during pregnancy is important for developing fetal bone strength and density and may play a role in preventing a range of skeletal and non-skeletal diseases in both mothers and children. We previously identified Mongolian women of reproductive age to have the lowest vitamin D levels yet observed in any population globally, which renders this population uniquely important in vitamin D research. In this study, we measured the seasonal distribution of 25-hydroxyvitamin D (25(OH)D) concentration in 390 healthy third trimester pregnant women living in urban and rural Mongolia using DiaSorin LIAISON and compared this distribution to that of 206 third trimester women living in Boston, USA. Also, we analyzed seasonally-independent associations between (25(OH)D) levels and selected predictors in both groups using quantile regression. Mean 25(OH)D levels were significantly higher and less seasonal in Boston (seasonal range: 27.1 ± 7.0-31.5 ± 7.7 ng/ml) than in Mongolia (seasonal range: 11.2 ± 3.9-19.2 ± 6.7 ng/ml). Adjusting for month of blood draw, higher 25(OH)D levels were significantly associated with older age, lower gravidity, lower BMI, and lack of a college or university degree among Boston participants, however, only gravidity was robust to multivariable adjustment. No assessed characteristics were independently predictive in Mongolia, likely due to universally low 25(OH)D levels and a resulting lack of between-person variation. In conclusion, vitamin D status among pregnant Mongolians is severely depressed throughout the year and should be addressed through fortification and supplementation, while in the U.S., deficiency is associated with specific characteristics targetable through supplementation.

Association of High-Dose Vitamin D Supplementation During Pregnancy With the Risk of Enamel Defects in Offspring: A 6-Year Follow-up of a Randomized Clinical Trial

IMPORTANCE

Enamel defects of developmental origin affect up to 38% of schoolchildren and is recognized as a global public health challenge. The impaired enamel formation results in pain owing to hypersensitivity, posteruptive breakdowns, rapid caries progression, and extractions in some cases. The etiology is unknown; therefore, prevention is currently not possible.

OBJECTIVE

To assess the association of a high-dose vitamin D supplementation in pregnant women with enamel defects and caries in their offspring.

DESIGN, SETTING, AND PARTICIPANTS

Post hoc analysis of a double-blind, single-center, randomized clinical trial, the Copenhagen Prospective Studies on Asthma in Childhood 2010 cohort (COPSAC2010). Enrollment began March 2009 and included 623 women recruited at 24 weeks of pregnancy and 588 of their children. A dental examination was completed at age 6 years in 496 of 588 children (84%). Data were analyzed in 2018.

INTERVENTION

High-dose vitamin D3 (2400 IU/d; N = 315) or matching placebo tablets (N = 308) from pregnancy week 24 to 1 week post partum. In addition, all women received 400 IU/d of vitamin D3 as part of standard care.

MAIN OUTCOMES AND MEASURES

Enamel defect was defined as having at least 1 molar affected by demarcated opacity, enamel breakdown, and/or atypical restoration. Caries was defined as decayed, missing, or filled surfaces in both the deciduous and permanent dentitions (World Health Organization standard).

RESULTS

The risk of enamel defects in the permanent dentition was lower in the offspring of mothers who received high-dose vitamin D supplementation during pregnancy compared with standard dose (15.1% [n = 26 of 172] vs 27.5% [n = 44 of 160]; odds ratio, 0.47; 95% CI, 0.27-0.81). A similar association was observed for the deciduous dentition (8.6% [n = 21 of 244] vs 15.9% [n = 40 of 252]; odds ratio, 0.50; 95% CI, 0.28-0.87). There was no association between supplementation and caries.

CONCLUSIONS AND RELEVANCE

High-dose vitamin D supplementation during pregnancy was associated with approximately 50% reduced odds of enamel defects in the offspring. This suggests prenatal vitamin D supplementation as a preventive intervention for enamel defects, with a clinically important association with dental health.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00856947.

Examining the predictive accuracy of metabolomics for small-for-gestational-age babies: a systematic review

INTRODUCTION

To date, there is no robust enough test to predict small-for-gestational-age (SGA) infants, who are at increased lifelong risk of morbidity and mortality.

OBJECTIVE

To determine the accuracy of metabolomics in predicting SGA babies and elucidate which metabolites are predictive of this condition.

DATA SOURCES

Two independent researchers explored 11 electronic databases and grey literature in February 2018 and November 2018, covering publications from 1998 to 2018. Both researchers performed data extraction and quality assessment independently. A third researcher resolved discrepancies.

STUDY ELIGIBILITY CRITERIA

Cohort or nested case-control studies were included which investigated pregnant women and performed metabolomics analysis to evaluate SGA infants. The primary outcome was birth weight <10th centile-as a surrogate for fetal growth restriction-by population-based or customised charts.

STUDY APPRAISAL AND SYNTHESIS METHODS

Two independent researchers extracted data on study design, obstetric variables and sampling, metabolomics technique, chemical class of metabolites, and prediction accuracy measures. Authors were contacted to provide additional data when necessary.

RESULTS

A total of 9181 references were retrieved. Of these, 273 were duplicate, 8760 were removed by title or abstract, and 133 were excluded by full-text content. Thus, 15 studies were included. Only two studies used the fifth centile as a cut-off, and most reports sampled second-trimester pregnant women. Liquid chromatography coupled to mass spectrometry was the most common metabolomics approach. Untargeted studies in the second trimester provided the largest number of predictive metabolites, using maternal blood or hair. Fatty acids, phosphosphingolipids and amino acids were the most prevalent predictive chemical subclasses.

CONCLUSIONS AND IMPLICATIONS

Significant heterogeneity of participant characteristics and methods employed among studies precluded a meta-analysis. Compounds related to lipid metabolism should be validated up to the second trimester in different settings.

PROSPERO REGISTRATION NUMBER

CRD42018089985.

Pregnancy or cord 25-hydroxyvitamin D is not associated with measures of body fat or adiposity in children from three months to three years of age. An Odense Child Cohort study

BACKGROUND & AIMS

The susceptibility to overweight in adults born during winter season may suggest foetal programming of prenatal vitamin D levels on adiposity. We investigated whether cord or pregnancy serum 25-hydroxyvitamin D (s-25OHD) was associated with infant and child body fat measures in a Danish population-based prospective cohort.

METHODS

In the Odense Child Cohort, 1905 singletons had cord s-25OHD and data on waist circumference (WC), weight, body mass index (BMI), and sum of skin folds (SSF) at median 3.7 months, 18.9 months and three years' age. Early and late pregnancy samples of s-25OHD (mean gestational age 12 and 29 weeks) were chosen as secondary exposures. Multiple linear and logistic regression as well as linear mixed models was applied testing the relation between cord and pregnancy s-25OHD and body fat outcomes and their Z-scores by use of updated national reference populations. Models were adjusted for maternal educational level, maternal ethnicity, pre-gestational BMI and season of birth, a priori stratified by sex.

RESULTS

The median [IQR] cord s-25OHD was 45.5 [31.1; 60.9] nmol/L. Cord s-25OHD <50 nmol/L was found in 57.5%; values < 25 nmol/L in 16.3%. The mean Z-scores of body fat measures at all ages were in the range of -0.32 to +0.42. No consistent associations were found between s-25OHD in cord, early pregnancy or late pregnancy and WC, weight, BMI, SSF, or their Z-scores at ages 3.7 months, 18.9 months, or 3 years. Neither did a computed composite outcome (WC, SSF, BMI, or weight >90th vs. ≤90 percentile) associate with cord or pregnancy s-25OHD.

CONCLUSION

Cord or pregnancy s-25OHD was not associated with measures of body fat or adiposity in children up to three years of age. Our data suggested no programming effect of maternal s-25OHD on offspring obesity in a relatively lean and healthy population of mothers.

Interventions for Prevention and Control of Epidemic of Vitamin D Deficiency

Vitamin D deficiency (VDD) remains a significant health challenge globally with its overwhelming effects on skeletal growth and varied associations with extra-skeletal diseases. The last decade has reported a high prevalence of VDD in all age-groups across all zones of India. Children and adolescents are most vulnerable to ill-effects of VDD as peak linear growth and bone mass accrual occurs during these years. Vitamin D deficiency in mothers predisposes their infants to have low serum vitamin D levels. Indians have increased susceptibility to develop VDD due to predominant vegetarian dietary habits, high melanin skin content, atmospheric pollution, modest tradition of clothing and limited availability of fortified foods. Vitamin D supplementation during infancy and childhood has emerged as an effective strategy to combat VDD. However, effects of vitamin D supplementation are transient and are not cost-effective as a maintenance strategy. Fortification of foodstuffs has been adopted by many developed countries globally which has emerged as a safe, efficacious and cost-effective strategy to control VDD. A strong political will and support is required to sustain food fortification in India. The current review focuses on strategies to prevent and control the epidemic of VDD in children.

Vitamin D and health - The missing vitamin in humans

Severe vitamin D deficiency may cause rickets in infants or children and osteomalacia in adults, though it is now uncommon in developed countries. However, subclinical vitamin D deficiency is more prevalent, and it is associated with osteoporosis and higher incidence of falls or fractures. It was reported that 96% children with rickets were breastfed, since breast milk contains inadequate vitamin D. The American Academy of Pediatrics 2008 recommended infants who were exclusively or partially breastfed required 400 international units vitamin D daily from the first few days of life. Furthermore, since vitamin D receptors are present all over the body, insufficient vitamin D status may correlate with several extra-skeletal effects, such as pregnancy-related complications and immune dysfunction. This paper discusses the researches regarding system-based vitamin D effects, the possible risk factors leading to vitamin D deficiency, and the recommendations of vitamin D requirements. It is well-known that vitamin D can be obtained by sun exposure or limited natural dietary sources. The American Academy of Dermatology declared ultraviolet radiation to be a known skin carcinogen, so it may not be safe or efficient to obtain vitamin D via sun exposure or other artificial sources. Therefore, many pediatricians and physicians recommend appropriate vitamin D supplementation to achieve optimal plasma concentration. Trials assessing the effects of vitamin D repletion and establishing its optimum serum level are ongoing. Medical advice for vitamin D supplementation should be individualized accordingly.

Maternal vitamin D deficiency and developmental origins of health and disease (DOHaD)

Vitamin D is an essential nutrient that is metabolized in the body to generate an active metabolite (1,25(OH)2D) with hormone-like activity and highly diverse roles in cellular function. Vitamin D deficiency (VDD) is a prevalent but easily preventable nutritional disturbance. Emerging evidence demonstrates the importance of sufficient vitamin D concentrations during fetal life with deficiencies leading to long-term effects into adulthood. Here, we provide a detailed review and perspective of evidence for the role of maternal VDD in offspring long term health, particularly as it relates to Developmental Origins of Health and Disease (DOHaD). We focus on roles in neurobehavioral and cardiometabolic disorders in humans and highlight recent findings from zebrafish and rodent models that probe potential mechanisms linking early life VDD to later life health outcomes. Moreover, we explore evidence implicating epigenetic mechanisms as a mediator of this link. Gaps in our current understanding of how maternal VDD might result in deleterious offspring outcomes later in life are also addressed.

Human health in relation to exposure to solar ultraviolet radiation under changing stratospheric ozone and climate

The Montreal Protocol has limited increases in the UV-B (280-315 nm) radiation reaching the Earth's surface as a result of depletion of stratospheric ozone. Nevertheless, the incidence of skin cancers continues to increase in most light-skinned populations, probably due mainly to risky sun exposure behaviour. In locations with strong sun protection programs of long duration, incidence is now reducing in younger age groups. Changes in the epidemiology of UV-induced eye diseases are less clear, due to a lack of data. Exposure to UV radiation plays a role in the development of cataracts, pterygium and possibly age-related macular degeneration; these are major causes of visual impairment world-wide. Photodermatoses and phototoxic reactions to drugs are not uncommon; management of the latter includes recognition of the risks by the prescribing physician. Exposure to UV radiation has benefits for health through the production of vitamin D in the skin and modulation of immune function. The latter has benefits for skin diseases such as psoriasis and possibly for systemic autoimmune diseases such as multiple sclerosis. The health risks of sun exposure can be mitigated through appropriate sun protection, such as clothing with both good UV-blocking characteristics and adequate skin coverage, sunglasses, shade, and sunscreen. New sunscreen preparations provide protection against a broader spectrum of solar radiation, but it is not clear that this has benefits for health. Gaps in knowledge make it difficult to derive evidence-based sun protection advice that balances the risks and benefits of sun exposure.

Associations of maternal vitamin D, PTH and calcium with hypertensive disorders of pregnancy and associated adverse perinatal outcomes: Findings from the Born in Bradford cohort study

Vitamin D and parathyroid hormone (PTH) regulate mineral metabolism and are required to maintain calcium levels. Vitamin D deficiency is common, particularly during pregnancy, and has been associated with hypertensive disorders of pregnancy. We sought to determine whether maternal 25(OH)D, PTH and calcium concentrations at 26 weeks gestation are associated with adverse outcomes of pregnancy and establish whether these differ by ethnicity. This study included 476 White British and 534 Pakistani origin mother-offspring pairs from the Born in Bradford cohort study. We used multinomial or logistic regression to explore the association between vitamin D, PTH and calcium with gestational hypertension (GH), pre-eclampsia (PE), caesarean section (CS), preterm birth (PTB) and small for gestational age (SGA). Pakistani women had lower 25(OH)D (median 13.0 vs 36.0 nmol/L), higher PTH (median 7.7 vs 3.3 pmol/L) and similar calcium concentrations compared to White British women. In Pakistani women, higher concentrations of 25(OH)D were associated with a 60% increased odds of GH, and a 37% reduced odds of SGA; PTH was associated with a 45% reduction in the odds of GH. In White British women, each 1 SD increase in calcium concentration was associated with a 34% increase in developing GH but a 33% reduction in the odds of PTB. Associations with PE and CS were consistent with the null. In conclusion, there are ethnic differences in the associations of 25(OH)D, PTH and calcium with important perinatal outcomes. Future research would benefit from examining the associations of 25(OH)D, PTH and calcium together with a range of perinatal outcomes in order to assess the risk-benefit action of each.

Vitamin D testing and treatment: a narrative review of current evidence

Vitamin D testing and treatment is a subject of controversial scientific discussions, and it is challenging to navigate through the expanding vitamin D literature with heterogeneous and partially opposed opinions and recommendations. In this narrative review, we aim to provide an update on vitamin D guidelines and the current evidence on the role of vitamin D for human health with its subsequent implications for patient care and public health issues. Vitamin D is critical for bone and mineral metabolism, and it is established that vitamin D deficiency can cause rickets and osteomalacia. While many guidelines recommend target serum 25-hydroxyvitamin D (25[OH]D) concentrations of ≥50 nmol/L (20 ng/mL), the minimum consensus in the scientific community is that serum 25(OH)D concentrations below 25-30 nmol/L (10-12 ng/mL) must be prevented and treated. Using this latter threshold of serum 25(OH)D concentrations, it has been documented that there is a high worldwide prevalence of vitamin D deficiency that may require public health actions such as vitamin D food fortification. On the other hand, there is also reason for concern that an exploding rate of vitamin D testing and supplementation increases costs and might potentially be harmful. In the scientific debate on vitamin D, we should consider that nutrient trials differ from drug trials and that apart from the opposed positions regarding indications for vitamin D treatment we still have to better characterize the precise role of vitamin D for human health.

The role of vitamin D in perinatology. An up-to-date review

The role of vitamin D in perinatology is a subject of major interest in current medicine. There is growing evidence about the role of maternal vitamin D levels in pregnancy outcomes. The aim of this review is to summarize the current literature about the role of vitamin D in perinatology. Evidence from this review suggests associations between low levels of maternal vitamin D and higher risk of certain obstetrical complications. Vitamin D has been found to be related to preeclampsia, gestational diabetes mellitus, low birth weight, and preterm birth. The current literature supports vitamin D supplementation in pregnant women, but more high-quality data are necessary. The problem that remains is how to achieve an optimal 25-hydroxyvitamin D level. To determine the real benefits of vitamin D supplementation in pregnancy, we need high-quality trials in larger groups.

Factors Associated with Serum 25-Hydroxyvitamin D Concentration in Two Cohorts of Pregnant Women in Southern Ontario, Canada

Vitamin D deficiency in pregnancy is widely reported, but whether this applies in North America is unclear since no population-based surveys of vitamin D status in pregnancy exist in Canada or the United States. The objectives were to assess (i) the intake and sources of vitamin D, (ii) vitamin D status, and (iii) factors associated with serum 25-hydroxyvitamin D (25-OHD) concentration in two cohorts of pregnant women from Southern Ontario, Canada, studied over a span of 14 years. Maternal characteristics, physical measurements, fasting blood samples and nutrient intake were obtained at enrolment in 332 pregnant women from the Family Atherosclerosis Monitoring In early Life (FAMILY) study and 191 from the Be Healthy in Pregnancy (BHIP) study. Serum 25-OHD was measured by LC/MS-MS. The median (Q1, Q3) total vitamin D intake was 383 IU/day (327, 551) in the FAMILY study and 554 IU/day (437, 796) in the BHIP study. Supplemental vitamin D represented 64% of total intake in participants in FAMILY and 78% in BHIP. The mean (SD) serum 25-OHD was 76.5 (32.9) nmol/L in FAMILY and 79.7 (22.3) nmol/L in BHIP. Being of European descent and blood sampling in the summer season were significantly associated with a higher maternal serum 25-OHD concentration. In summary, health care practitioners should be aware that vitamin D status is sufficient in the majority of pregnant Canadian women of European ancestry, likely due to sun exposure.

Maternal risk factors and newborn infant vitamin D status: a scoping literature review

Low vitamin D (VitD) status is common among newborn infants, more so in temperate latitudes with evidence that maternal VitD deficiency is a major risk factor given that the neonate relies solely on maternal-fetal transfer of VitD. This scoping review was conducted to provide an overview of the latest evidence from studies regarding the impact of maternal risk factors on infant 25-hydryoxyvitamin D [25(OH)D] concentrations with a focus on studies in Canada and the United States. Several maternal risk factors that contribute to low maternal-fetal 25(OH)D concentrations have been reported over many decades, but no clear pattern has been established for multiethnic populations. For example, darker skin pigmentation and ethnicity are common risk factors for low VitD status. Studies in predominantly white women showed that supplementation of VitD during pregnancy causes significant increases in maternal serum 25(OH)D which often improves cord serum 25(OH)D values. In addition, VitD recommendations by health care professionals and adherence to supplementation by pregnant women appear to positively influence maternal and infant 25(OH)D concentrations. Conversely, winter season, obesity, lower socioeconomic status including lifestyle factors (smoking), and use of medication pose risk for lower maternal-fetal transfer of VitD. However, there is still a dearth of pertinent data on the relationship between some of the maternal risk factors and newborn 25(OH)D concentrations, for instance, relationships between gestational diabetes and neonatal VitD status. Additional research is required to determine if the same target for 25(OH)D concentrations applies for pregnant women, neonates, and infants.

The Role of Vitamin D in Fertility and during Pregnancy and Lactation: A Review of Clinical Data

Vitamin D deficiency is common and there exists a huge gap between recommended dietary vitamin D intakes and the poor vitamin D supply in the general population. While vitamin D is important for musculoskeletal health, there are accumulating data suggesting that vitamin D may also be important for fertility, pregnancy outcomes and lactation. Significant changes in vitamin D metabolism during pregnancy such as increased production of the “active vitamin D hormone” calcitriol support the important role of vitamin D in this setting. Observational studies show that vitamin D deficiency is a risk marker for reduced fertility and various adverse pregnancy outcomes and is associated with a low vitamin D content of breast milk. Meta-analyses of randomized controlled trials (RCTs) document that physiological vitamin D supplementation during pregnancy is safe and improves vitamin D and calcium status, thereby protecting skeletal health. Although certain RCTs and/or meta-analyses reported some other beneficial effects, it is still not clear whether vitamin D supplementation improves fertility or decreases the risk of adverse pregnancy outcomes such as low birth weight, pre-eclampsia and neonatal mortality, or reduces wheeze/asthma in the infants. Nevertheless, vitamin D supplementation in pregnant women is frequently required to achieve a sufficient vitamin D status as recommended by nutritional vitamin D guidelines. In this review, we provide an overview of systematic reviews, meta-analyses and large trials reporting clinical data on the role of vitamin D for fertility, pregnancy and lactation.

Update of the tolerable upper intake level for vitamin D for infants

Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to revise the tolerable upper intake level (UL) for vitamin D for infants (≤ 1 year) set in 2012. From its literature review, the Panel concluded that the available evidence on daily vitamin D intake and the risk of adverse health outcomes (hypercalciuria, hypercalcaemia, nephrocalcinosis and abnormal growth patterns) cannot be used alone for deriving the UL for infants. The Panel conducted a meta-regression analysis of collected data, to derive a dose-response relationship between daily supplemental intake of vitamin D and mean achieved serum 25(OH)D concentrations. Considering that a serum 25(OH)D concentration of 200 nmol/L or below is unlikely to pose a risk of adverse health outcomes in infants, the Panel estimated the percentage of infants reaching a concentration above this value at different intakes of vitamin D. Based on the overall evidence, the Panel kept the UL of 25 μg/day for infants aged up to 6 months and set a UL of 35 μg/day for infants 6-12 months. The Panel was also asked to advise on the safety of the consumption of infant formulae with an increased maximum vitamin D content of 3 μg/100 kcal (Commission Delegated Regulation (EU) 2016/127 repealing Directive 2006/141/EC in 2020). For infants aged up to 4 months, the intake assessment showed that the use of infant formulae containing vitamin D at 3 μg/100 kcal may lead some infants to receive an intake above the UL of 25 μg/day from formulae alone without considering vitamin D supplemental intake. For infants aged 4-12 months, the 95th percentile of vitamin D intake (high consumers) estimated from formulae and foods fortified or not with vitamin D does not exceed the ULs, without considering vitamin D supplemental intake.

Effect of Nutritional Interventions on Micronutrient Status in Pregnant Malawian Women with Moderate Malnutrition: A Randomized, Controlled Trial

Micronutrient deficiencies during pregnancy are common in Africa and can cause adverse outcomes. The objective was to measure micronutrient status and change in moderately malnourished pregnant Malawian women randomized to one of three nutritional interventions. Serum vitamin B₁₂, 25-hydroxyvitamin D, folate, retinol, ferritin, zinc, albumin and C-reactive protein were measured in pregnant women with MUAC &ge;20.6 cm and &le;23.0 cm at enrollment (n = 343) and after 10 weeks (n = 229) of receiving: (1) ready-to-use supplementary food (RUSF); (2) fortified corn-soy blend (CSB+) with multiple-micronutrient supplement (CSB+UNIMMAP); or (3) CSB+ with iron and folic acid (CSB+IFA). Each provided 100⁻300% Recommended Dietary Allowance of most micronutrients and 900 kcal/day. Birth length was measured in 272 infants. Enrollment measurements indicated deficiencies in vitamin B₁₂ (20.9%) and zinc (22.3%), low values of ferritin (25.1%) and albumin (33.7%), and elevated CRP (46.0%). Vitamin B₁₂ is known to decrease in the third trimester; the RUSF group had the smallest decrease from enrollment to week 10 (3%), compared to 20% decrease in the CSB+IFA group and 8% decrease in the CSB+UNIMMAP group (p = 0.001). Mean serum 25-hydroxyvitamin D increased most in the RUSF group (+6.4 ng/mL), compared to CSB+IFA (+1.7 ng/mL) and CSB+UNIMMAP (+2.7 ng/mL) (p < 0.001). Micronutrient deficiencies and inflammation are common among moderately malnourished pregnant women and had little improvement despite supplementation above the RDA, with the exception of vitamins B₁₂ and D.