Dietary supplements contribute substantially to the total nutrient intake in pregnant Norwegian women

The effect of folic acid intake on congenital anomalies. A systematic review and meta-analysis

Background

Congenital anomalies pose a significant challenge to global health and result in considerable morbidity and mortality in early childhood. With the decline of other causes of death among children under five, the burden of congenital anomalies is rising, emphasizing the need for improved prenatal care, screening, and nutrition for pregnant women. This systematic review and meta-analysis aim to estimate the pooled effect of folic acid intake on congenital anomalies.

Methods

To identify relevant research published up until December 30/2023, we conducted electronic searches of PubMed/Medline, PubMed Central, Hinary, Google, African Journals Online, Web of Science, Science Direct, and Google Scholar databases using predefined eligibility criteria. We used Excel to extract data and evaluated the studies using the JBI appraisal checklist. We computed the pooled effect size with 95% confidence intervals for maternal folic acid intake on congenital anomalies using STATA version 17 and the DerSimonian and Laird random effects meta-analysis model. We assessed statistical heterogeneity using Cochran's Q-test, I 2 statistic, and visual examination of the funnel plot.

Results

The review included 16 case-control, cohort, and cross-sectional studies. According to the results of this systematic review and meta-analysis, maternal folic acid intake significantly lowers the incidence of congenital anomalies (odds ratio (OR), 0.23; confidence interval (CI), 0.16, 0.32). Among the included studies, both the Cochrane Q-test statistic (χ2 = 118.82, p < 0.001) and I 2 test statistic (I 2 = 87.38%, p < 0.001) revealed statistically significant heterogeneity. Egger's weighted regression (p < 0.001) and funnel plot show evidence of publication bias in this meta-analysis.

Conclusion

The results of the recent meta-analysis and systematic review have demonstrated a significant association between maternal folic acid intake and the risk of congenital anomalies. Specifically, children whose mothers received periconceptional folic acid supplementation had a 77% reduced risk of congenital anomalies. To further investigate the correlation between maternal folic acid supplementation and the occurrence of various congenital anomalies, particularly in developing countries, it is recommended that a comprehensive prospective study be conducted.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, PROSPERO (CRD42024511508).

A Study of Vitamin D Status and Its Influencing Factors among Pregnant Women in Szeged, Hungary: A Secondary Outcome of a Case-Control Study

Adequate vitamin D (VD) intake during pregnancy is needed for fetal development and maternal health maintenance. However, while there is no doubt regarding its importance, there is not a unified recommendation regarding adequate intake. The main aim of our study was to measure the VD serum level of studied women, together with its potential influencing factors: demographic (i.e., age, level of education, relationship status and type of residence), conception and pregnancy related factors. Results are based on secondary data analyses of a retrospective case-control study of 100 preterm and 200 term pregnancies, where case and control groups were analyzed together. Data collection was based on a self-administered questionnaire, health documentation, and maternal serum VD laboratory tests. VD intake was evaluated by diet and dietary supplement consumption. According to our results, 68.1% of women took some kind of prenatal vitamin, and only 25.9% of them knew about its VD content. Only 12.1% of included women reached the optimal, 75 nmol/L serum VD level. Higher maternal serum levels were associated with early pregnancy care visits (p = 0.001), assisted reproductive therapy (p = 0.028) and advice from gynecologists (p = 0.049). A correlation was found between VD intake and serum levels (p < 0.001). Despite the compulsory pregnancy counselling in Hungary, health consciousness, VD intake and serum levels remain below the recommendations. The role of healthcare professionals is crucial during pregnancy regarding micronutrients intake and the appropriate supplementation dose.

Supplement use in relation to dietary intake in pregnancy: an analysis of the Swedish GraviD cohort

We aimed to study supplement use in relation to dietary intake among pregnant women in Sweden, and adherence to the Nordic Nutrition Recommendations among supplement and non-supplement users. Pregnant women were recruited at registration to antenatal care in 2013–2014. In third trimester, supplement use was collected using a questionnaire, and dietary intake was collected using a FFQ. The majority (64 %) of the 1044 women reported use of one or more supplements. Among all, 0–23 % reported dietary intakes above recommended intake (RI) of vitamin D, folate, Fe and Se. Median dietary intakes of thiamine (1·4 v. 1·3 mg P = 0·013), phosphorus (1482 v. 1440 mg P = 0·007), folate (327 v. 316 µg P = 0·02), Fe (12 v. 11·5 mg P = 0·009), Mg (361 v. 346 mg P < 0·001) and Zn (10·7 v. 10·4 mg P = 0·01) were higher among supplement users compared with non-users. Larger proportions of supplement users than non-users adhered to RI of dietary intakes of thiamine (42 % v. 35 % P = 0·04) and Mg (75 % v. 69 % P = 0·05). Among non-users, a minority had dietary intakes above RI for vitamin D (6 %), folate (10 %) and Fe (21 %). The majority (75–100 %) of supplement users had total intakes above RI for most nutrients. In conclusion, supplement use contributed substantially to reaching RI for vitamin D, folate and Fe. Supplement users had a higher dietary intake of several nutrients than non-users. This highlights that non-supplement users are at risk of inadequate nutrient intakes during pregnancy, suggesting a need for heightened awareness of nutritional adequacy for pregnant women.

Folate - a scoping review for Nordic Nutrition Recommendations 2023

Folate is an essential micronutrient for normal development and metabolic function, and folate deficiency is associated with an increased risk of cancer, cardiovascular disease, mental dysfuntion and negative pregnancy outcomes. When estimating folate requirements, one must consider different bioavailability and functionality between synthetic folic acid and dietary folate, together with increased needs of folate in women of fertile age, pregnant and lactating women, preterm and small for gestational age weight infants and individuals who are homozygote for the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene polymorphism. In order to achieve an adequate metabolic status based on the metabolic marker total homocysteine, and not merely the absence of clinical signs of folate deficiency, the recommended intake of folate differs according to age, pregnancy and lactation. According to the World Health Organization, a decision limit for folate deficiency in adults is serum folate level below 10 nmol/L, and in women of fertile age a red blood cell folate level below 906 nmol/L in order to prevent neural tube defects. Qualified systematic reviews along with identified relevant literature have been used for this scoping review prepared for the Nordic Nutrition Recommendations 2023.

Vitamin B6: a scoping review for Nordic Nutrition Recommendations 2023

Pyridoxal 5´-phosphate (PLP) is the main form of vitamin B6 in animal tissue and functions as a coenzyme for more than 160 different enzymatic reactions in the metabolism of amino acids, carbohydrates, lipids, and neurotransmitters. Estimated dietary intake of vitamin B6 and plasma PLP values differ a lot between studies, something which may be due to variable use of supplements, variations in dietary assessment and analytical methods. These factors make it difficult to achieve precise data for setting a correct recommended intake of vitamin B6. In addition, a plasma PLP concentration of 30 nmol/L is considered to be sufficient and the current recommendations for vitamin B6 intake is based on this concept. However, the metabolic marker for vitamin B6 status, HK ratio (HKr), starts to increase already when plasma PLP falls below 100 nmol/L and increases more steeply below 50 nmol/L, indicating biochemical deficiency. Consequently, a plasma PLP concentration of 30 nmol/L, may be too low as a marker for an adequate vitamin B6 status.

Vitamin D intake and determinants of vitamin D status during pregnancy in The Norwegian Mother, Father and Child Cohort Study

Background

Norwegian data on vitamin D status among pregnant women indicate a moderate to high prevalence of insufficient vitamin D status (25-hydroxyvitamin D (25OHD) concentrations ≤50  nmol/L). There is a lack of population-based research on vitamin D intake and determinants of 25OHD in pregnant women from northern latitudes. The aims of this study were (1) to evaluate total vitamin D intake from both diet and supplements, (2) to investigate determinants of vitamin D status, and (3) to investigate the predicted response in vitamin D status by total vitamin D intake, in pregnant Norwegian women.

Methods

In total, 2,960 pregnant women from The Norwegian Environmental Biobank, a sub-study within The Norwegian Mother, Father and Child Cohort Study (MoBa), were included. Total vitamin D intake was estimated from a food frequency questionnaire in gestational week 22. Concentrations of plasma 25OHD was analyzed by automated chemiluminescent microparticle immunoassay method in gestational week 18. Candidate determinant variables of 25OHD were chosen using stepwise backward selection and investigated using multivariable linear regression. Predicted 25OHD by total vitamin D intake, overall and stratified by season and pre-pregnancy BMI, was explored using restricted cubic splines in an adjusted linear regression.

Results

Overall, about 61% of the women had a total vitamin D intake below the recommended intake. The main contributors to total vitamin D intake were vitamin D supplements, fish, and fortified margarine. Higher 25OHD concentrations were associated with (in descending order of the beta estimates) summer season, use of solarium, higher vitamin D intake from supplements, origin from high income country, lower pre-pregnancy BMI, higher age, higher vitamin D intake from foods, no smoking during pregnancy, higher education and energy intake. During October-May, a vitamin D intake according to the recommended intake was predicted to reach sufficient 25OHD concentrations >50  nmoL/L.

Conclusion

The findings from this study highlight the importance of the vitamin D intake, as one of few modifiable determinants, to reach sufficient 25OHD concentrations during months when dermal synthesis of vitamin D is absent.

The impact of recommending iron supplements to women with depleted iron stores in early pregnancy on use of supplements, and factors associated with changes in iron status from early pregnancy to postpartum in a multi-ethnic population-based cohort

BACKGROUND

We aimed to evaluate the impact of recommending supplementation to pregnant women with serum ferritin (SF) < 20 µg/L in early pregnancy on use of supplements, and to explore which factors were associated with changes in iron status by different iron indicators to 14 weeks postpartum.

METHODS

A multi-ethnic population-based cohort study of 573 pregnant women examined at mean gestational week (GW) 15 (enrolment), at mean GW 28 and at the postpartum visit (mean 14 weeks after delivery). Women with SF < 20 µg/L at enrolment were recommended 30-50 mg iron supplementation and supplement use was assessed at all visits. Change of SF, soluble transferrin receptor and total body iron from enrolment to postpartum were calculated by subtracting the concentrations at the postpartum visit from that at enrolment. Linear and logistic regression analyses were performed to assess associations between use of supplements in GW 28 and changes in iron status and postpartum iron deficiency/anaemia. Change of iron status was categorized into 'steady low', 'improvement', 'deterioration', and 'steady high' based on SF status at enrolment and postpartum. Multinomial logistic regression analyses were performed to identify factors associated with change of iron status.

RESULTS

At enrolment, 44% had SF < 20 µg/L. Among these women (78% non-Western European origin), use of supplements increased from 25% (enrolment) to 65% (GW 28). Use of supplements in GW 28 was associated with improved iron levels by all three indicators (p < 0.05) and with haemoglobin concentration (p < 0.001) from enrolment to postpartum, and with lower odds of postpartum iron deficiency by SF and TBI (p < 0.05). Factors positively associated with 'steady low' were: use of supplements, postpartum haemorrhage, an unhealthy dietary pattern and South Asian ethnicity (p ≤ 0.01 for all); with 'deterioration': postpartum haemorrhage, an unhealthy dietary pattern, primiparity and no use of supplements (p < 0.01 for all), and with 'improvement': use of supplements, multiparity and South Asian ethnicity (p < 0.03 for all).

CONCLUSIONS

Both supplement use and iron status improved from enrolment to the postpartum visit among women recommended supplementation. Dietary pattern, use of supplements, ethnicity, parity and postpartum haemorrhage were identified as factors associated with change in iron status.

The prevalence of trimester-specific dietary supplements and associated factors during pregnancy: An observational study

Objectives: This study aimed to assess the prevalence of trimester-specific dietary supplements (DS)s use and their possible correlates during pregnancy.

Method: Pregnant women were convenience sampled and recruited from a comprehensive obstetric care center in Shanghai, China. Data relating to the use of DS during pregnancy, social support and other social-demographic and obstetric data were collected. Trimester-specific DS use and factors related DS were explored.

Results: Of the 2803 women participating in this study, 94.8%, 96.2%, 93.8%, and 94.4% reported the use of at least one DS during pregnancy (all trimesters) and in the first, second, and third trimesters of pregnancy, respectively. Significant differences were noted in the use of DS containing folic acid, calcium, iron, vitamins, and docosahexaenoic acid (DHA), during the three trimesters of pregnancy. A higher proportion of DS use was negatively associated with certain categories of pregnant woman, including unemployed/housewife, low education level, obese, and low social support. A positive association was identified with gestational age.

Conclusion for practice: Considering the high prevalence of DS use during pregnancy, future studies are needed to evaluate the accuracy and suitability of DS usage during pregnancy.

Dietary Intake of Micronutrients and Essential Fatty Acids among Overweight or Obese Pregnant Women during Early Pregnancy

Background

Dietary intake of micronutrients and essential fatty acids in overweight or obese pregnant women during early pregnancy is unknown. We investigated the proportion of pregnant women meeting recommendations for dietary intake of micronutrients and essential fatty acids and compared stress and depressive symptoms between those meeting and below recommendations.

Methods

Participants (N = 70) were overweight or obese pregnant women ≤16 weeks gestation. They completed two 24-hour dietary recalls and online surveys measuring stress and depressive symptoms. Micronutrients of interest included B vitamins, choline, and trace minerals (calcium, magnesium, selenium, and zinc). Essential fatty acids were docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).

Results

Low proportions of participants met recommendations for choline (21.4%) and folate (24.3%). Yet, the proportion of women meeting recommendations for other B vitamins and trace minerals were much better. Less than 9.0% of participants met recommendations for essential fatty acids. Compared with those below recommendations for B3 and selenium, participants meeting recommendations had significantly fewer depressive symptoms.

Conclusions

Low proportions of overweight or obese pregnant participants met dietary intake recommendations for micronutrients and essential fatty acids.

Assessment of vitamin B6 status in never-pregnant, pregnant and postpartum women and their infants

PURPOSE

Pyridoxal 5´-phosphate (PLP) is the main form of vitamin B6 in humans and functions a coenzyme for more than 160 different enzymatic reactions. The purpose of the study was to find plasma PLP concentrations, which ensure an optimal vitamin B6 status determined by a metabolic marker, in never-pregnant, pregnant and lactating women and their infants.

METHODS

In an observational, prospective study, plasma PLP and the metabolic marker, HKr (hydroxykynurenine/(kynurenic acid + anthranilic acid + xanthurenic acid + hydroxyanthranilic acid) were assessed in women (n = 114) from pregnancy week 18 to 6 months postpartum and related to infant status. Never-pregnant women 18-40 years (n = 127) were included as controls.

RESULTS

Compared to controls, plasma PLP decreased during pregnancy and increased postpartum, while HKr increased from week 18 to 6 weeks postpartum, indicating maternal vitamin B6 insufficiency during this period. In never-pregnant women, HKr increased gradually with plasma PLP < 100 nmol/L, and in pregnancy week 28 a sharp increase in HKr was seen at plasma PLP < 30 nmol/L. Despite correcting for maternal vitamin B6 status, infant median plasma PLP decreased with months of exclusive breastfeeding.

CONCLUSIONS

Plasma PLP and kynurenine concentrations differ substantially between never-pregnant, pregnant and postpartum women and infants. A plasma PLP concentration in the range of 50-100 nmol/L seems to ensure an optimal vitamin B6 status for never-pregnant women, whereas a plasma PLP > 30 nmol/L in pregnancy week 28 ensures an adequate vitamin B6 status during pregnancy and lactation. Infant vitamin B6 status at age 6 months is inversely correlated to number of months of exclusive breastfeeding.

Exposure to arsenolipids and inorganic arsenic from marine-sourced dietary supplements

Dietary supplements sourced from marine environments, such as fish oils and seaweed-based supplements, are widely consumed to boost nutrient intakes, including by vulnerable populations such as pregnant women. Like other marine foods, these supplements are also a potential source of exposure to arsenic, including the known toxic species, inorganic arsenic, and the cytotoxic, lipid-soluble arsenic compounds, arsenic hydrocarbons. A study of 32 marine-sourced supplements found higher total arsenic concentrations (>1000 ng g^-1) in supplements made from seaweed, krill and calanus oil, and in fish and fish liver products marketed as "unprocessed". Inorganic arsenic was only detectable in the seaweed samples, and was elevated (8900 ng g^-1) in one product. Arsenic hydrocarbons were not detected in krill oil samples but were present at concentrations from 169 to 2048 ng g^-1 in "unprocessed" fish and fish liver oil, and calanus oil. Survey data from the New Hampshire Birth Cohort Study (NHBCS) found 13.5% of pregnant women (n = 1997) reported taking fish oil supplements; and of those, most did so daily (75.6%, 6 or more times per week). Only a small percentage (9%) of those who reported consuming fish oil used products associated with higher arsenic levels. Higher urinary arsenic concentrations were found among women who consumed fish oil compared with those who did not, and specifically higher arsenobetaine and dimethyl arsenic concentrations. Dietary supplements are becoming common components of modern diets, and some marine-sourced dietary supplements are a source of inorganic arsenic and arsenic hydrocarbons.

Dietary Supplement Use during Pregnancy: Perceptions versus Reality

This study aimed to examine the prevalence, associated factors and perceptions of dietary supplement use among pregnant Chinese women. A cross-sectional study was conducted to collect data about prevalence, purchase channels, perceptions, and related factors of dietary supplement use from 572 pregnant women, through a face-to-face survey, using a self-designed questionnaire. Of the respondents, 94.8% used at least one dietary supplement, whereas 29.8% used more than four supplements in the previous month. The majority of the pregnant women were highly educated (81.2% had a bachelor’s degree or above) and had the perception that dietary supplements could prevent and improve (89.2%), or treat, nutrition-related diseases (78.7%). Multivariate analysis showed that pregnant women who had used multiple (more than four) supplements were more likely to have a larger gestational age, received fertility treatment, more prenatal visits, and hypothyroidism during pregnancy. Furthermore, pregnant women not only purchased dietary supplements through hospitals (72.6%) and pharmacies (45.1%), but overseas Daigou or online purchases (31.8%) were also a major channel of purchase. A high prevalence of dietary supplement use during pregnancy was observed, with extensive and repeated consumption of nutrients. Pregnant women’s craze for dietary supplements calls for more comprehensive guidelines in China.

Gestational blood levels of toxic metal and essential element mixtures and associations with global DNA methylation in pregnant women and their infants

BACKGROUND

Pregnant women and their fetuses are exposed to multiple toxic metals that together with variations in essential element levels may alter epigenetic regulation, such as DNA methylation.

OBJECTIVES

The aim of the study was to investigate the associations between gestational levels of toxic metals and essential elements and mixtures thereof, with global DNA methylation levels in pregnant women and their newborn children.

METHODS

Using 631 mother-child pairs from a prospective birth cohort (The Norwegian Mother, Father and Child Cohort Study), we measured maternal blood concentration (gestation week ~18) of five toxic metals and seven essential elements. We investigated associations as individual exposures and two-way interactions, using elastic net regression, and total mixture, using quantile g-computation, with blood levels of 5-methylcytocine (5mC) and 5-hydroxymethylcytosine (5hmC) in mothers during pregnancy and their newborn children (cord blood). Multiple testing was adjusted for using the Benjamini and Hochberg false discovery rate (FDR) approach.

RESULTS

The most sensitive marker of DNA methylation appeared to be 5mC levels. In pregnant mothers, elastic net regression indicated associations between 5mC and selenium and lead (non-linear), while in newborns results indicated relationships between maternal selenium, cobalt (non-linear) and mercury and 5mC, as well as copper (non-linear) and 5hmC levels. Several possible two-way interactions were identified (e.g. arsenic and mercury, and selenium and maternal smoking in newborns). None of these findings met the FDR threshold for multiple testing. No net effect was observed in the joint (mixture) exposure-approach using quantile g-computation.

CONCLUSION

We identified few associations between gestational levels of several toxic metals and essential elements and global DNA methylation in pregnant mothers and their newborn children. As DNA methylation dysregulation might be a key mechanism in disease development and thus of high importance for public health, our results should be considered as important candidates to investigate in future studies.

Use of Iodine Supplements by Breastfeeding Mothers Is Associated with Better Maternal and Infant Iodine Status

Adequate iodine status during conception, pregnancy and lactation is essential for supporting infant neurodevelopment. Iodine status in adults and children was improved after two New Zealand government initiatives, but the status of breastfeeding women is unknown. This study aimed to investigate the iodine intake and status of lactating mother-infant pairs at 3 months postpartum and to assess maternal iodine knowledge and practice. Iodine intake was estimated by a weighed 4-day diet diary (4DDD). Maternal urinary iodine concentrations (UIC) in spot urine, breast milk iodine concentrations (BMIC) and infant UIC were measured. Questions about iodine-specific knowledge and practice were asked. In 87 breastfeeding mother-infant pairs, maternal iodine intake was 151 (99, 285) μg/day, and 58% had an intake below the estimated average requirement (EAR) of 190 μg/day. Maternal median UIC (MUIC) was 82 (46, 157) μg/L indicating iodine deficiency (i.e., < 100 μg/L). Women who used iodine-containing supplements had a significantly higher MUIC (111 vs 68 μg/L, P = 0.023) and BMIC (84 vs 62 μg/L, P < 0.001) than non-users. Infants fed by women using iodine-containing supplements had a higher MUIC (150 vs 86 μg/L, P = 0.036) than those of non-users. A total of 66% (57/87) of women had no or low iodine knowledge. The iodine knowledge score was a statistically significant predictor of consuming iodine-containing supplements [(beta = 1.321, P = 0.008)]. Despite a decade of initiatives to increase iodine intakes in New Zealand, iodine knowledge was low; iodine intake and status of these lactating women were suboptimal, but women who used iodine-containing supplement were more likely to achieve adequate status.Study Registration Number (Australia and New Zealand Clinical Trials Registry): ACTRN12615001028594.

Maternal Dietary Selenium Intake during Pregnancy and Neonatal Outcomes in the Norwegian Mother, Father, and Child Cohort Study

Properly working antioxidant defence systems are important for fetal development. One of the nutrients with antioxidant activity is selenium. Increased maternal selenium intake has been associated with reduced risk for being small for gestational age and preterm delivery. Based on the Norwegian Mother, Father, and Child Cohort Study and the Medical Birth Registry of Norway, we investigated the association of maternal selenium intake from food and dietary supplements during the first half of pregnancy (n = 71,728 women) and selenium status in mid-pregnancy (n = 2628 women) with neonatal health, measured as two composite variables (neonatal morbidity/mortality and neonatal intervention). Low maternal dietary selenium intake (<30 µg/day) was associated with increased risk for neonatal morbidity/mortality (adjusted odds ratio (adjOR) 1.36, 95% confidence interval (95% CI) 1.08–1.69) and neonatal intervention (adjOR 1.16, 95% CI 1.01–1.34). Using continuous variables, there were no associations between maternal selenium intake (from diet or supplements) or whole-blood selenium concentration and neonatal outcome in the adjusted models. Our findings suggest that sufficient maternal dietary selenium intake is associated with neonatal outcome. Adhering to the dietary recommendations may help ensure an adequate supply of selenium for a healthy pregnancy and optimal fetal development.

The impact of micronutrient deficiency on pregnancy complications and development origin of health and disease

Due to the spread of the western style diet, which is characterized by high intake of processed food, micronutrients (vitamins and minerals) deficiency is increasing in the Japanese population of all ages and genders. During pregnancy, the elevated demand for micronutrients put pregnant women at even higher risk of micronutrients deficiency. Some micronutrients are relatively famous such that women with reproductive age are recommended to take folic acid supplementation for the prevention of neural tube defect. However, it is not generally known that folate is also important for fetal growth throughout the pregnancy course and for prevention of pregnancy complications, and that pregnant women should continue to take supplementation during pregnancy and lactation. The types of micronutrients and the duration of supplementation are both important factors to maintain normal pregnancies. This review focused on four micronutrients that are commonly deficient in Japanese pregnant women, folate, vitamin B12, vitamin D, calcium, and magnesium. The detrimental effects of homocysteine accumulation associated with the above micronutrient defects and its link to catechol-o-methyltransferase insufficiency are described. We also discussed possible molecular mechanisms of pregnancy complications and the development origin of health and disease (DOHaD) regarding micronutrient deficiencies from the point of view of one carbon metabolism.

Iron status in mid-pregnancy and associations with interpregnancy interval, hormonal contraceptives, dietary factors and supplement use

Adequate iron supply in pregnancy is important for both the woman and the fetus, but iron status is often assessed late in first trimester, if assessed at all. Therefore, identification of factors associated with iron status is important to target vulnerable groups with increased risk of deficiency. Our objectives were to (1) describe iron status in mid-pregnancy and (2) identify sociodemographic and lifestyle predictors of pregnancy iron status. This cross-sectional study uses data from The Norwegian Mother, Father and Child Cohort Study (collected 2002-2008) and The Medical Birth Registry of Norway. Iron status was measured as non-fasting plasma ferritin (P-Fe) and transferrin in gestational week (GW) 18 (n 2990), and by lowest reported Hb in GW 0-30 (n 39 322). We explored predictors of iron status with elastic net, linear and log-binomial regression models. Median P-Fe was 33 μg/l, and 14 % had depleted iron stores (P-Fe <15 μg/l). P-Fe below 30 μg/l was associated with reduced Hb. We identified eleven predictors, with interpregnancy interval (IPI) and parity among the most important. Depleted iron stores was more common among women with IPI < 6 months (56 %) and 6-11 months (33 %) than among those with IPI 24-59 months (19 %) and among nulliparous women (5 %). Positively associated factors with iron status included hormonal contraceptives, age, BMI, smoking, meat consumption and multi-supplement use. Our results highlight the importance of ferritin measurements in women of childbearing age, especially among women not using hormonal contraceptives and women with previous and recent childbirths.

Vitamin D insufficiency among Danish pregnant women-Prevalence and association with adverse obstetric outcomes and placental vitamin D metabolism

INTRODUCTION

In pregnancy, vitamin D deficiency is associated with increased risk of fetal growth restriction and preeclampsia. The underlying mechanisms are not known, but placental dysfunction is believed to play a role. In a Danish population, where health authorities recommend a 10 µg/day vitamin D supplement during pregnancy, we explored current use of vitamin D supplements and vitamin D status. In term placentas, alterations in vitamin D metabolism and placental growth, evaluated by the key placental growth factor pregnancy-associated plasma protein-A (PAPP-A), and their relation to vitamin D insufficiency were investigated.

MATERIAL AND METHODS

We included 225 randomly selected pregnant women attending a nuchal translucency scan at gestational weeks 11-14. Information on use of vitamin D supplements and body mass index (BMI) at inclusion was obtained using self-reported questionnaires. Plasma 25-hydroxyvitamin D was measured at inclusion and correlated with pregnancy outcomes and placental biology, as judged by expression of PAPP-A and enzymes involved in vitamin D metabolism (CYP24A1, CYP27B1) in term placentas.

RESULTS

Vitamin D supplements were used by 92% of the women, but 42% were vitamin D insufficient (plasma 25-hydroxyvitamin D <75 nmol/L). Eleven women with singleton pregnancies developed fetal growth restriction or preeclampsia. In this small subset, first-trimester mean plasma 25-hydroxyvitamin D was lower in women who developed fetal growth restriction (43 ± 33nmol/L; n = 3; P = .006) and there was a tendency towards lower plasma 25-hydroxyvitamin D among women who developed preeclampsia (65 ± 19 nmol/L; n = 8; P = .08) in third trimester compared with uncomplicated pregnancies (79 ± 22 nmol/L; n = 187). In term placentas, PAPP-A expression was lower among participants with first-trimester vitamin D insufficiency (P = .009; n = 30) but no correlation was found between plasma 25-hydroxyvitamin D and mRNA expression of CYP24A1 (P = .67) and CYP27B1 (P = .34). BMI was negatively correlated with plasma 25-hydroxyvitamin D (P = .03) and positively correlated with placental mRNA expression of CYP24A1 (P = .003; n = 30).

CONCLUSIONS

Despite high compliance with official guidelines regarding vitamin D supplements, vitamin D insufficiency was frequent and the findings indicate that vitamin D insufficiency may affect placental growth. High BMI was associated with vitamin D insufficiency and increased placental vitamin D turnover, but further investigations are needed.

Dietary intake of carbohydrates in pregnant women with type 1 diabetes-A narrative review

In pregnant women with type 1 diabetes, a low but sufficient, intake of carbohydrates is important to aim for near normal glycemic control. However, knowledge about the carbohydrate intake in this group is limited. To assess the average quantity and quality of carbohydrate intake in pregnant women with type 1diabetes compared to healthy pregnant women and current dietary reference intakes. A narrative literature search was performed in PubMed, Embase, and Cochrane Library and by using a snow-ball search technique to identify papers published on studies conducted in industrialized countries within the last 20 years. Intakes of carbohydrate were assessed qualitatively in relation to the Dietary Reference Intakes recommended by the American Diabetes Association and quantitatively as mean intake of dietary fiber. Five observational studies including 810 pregnant women with type 1 diabetes and 15 observational studies with a total of 118,246 healthy pregnant women were identified. The mean total carbohydrate intake was within the Acceptable Macronutrient Distribution Range (45%-64% of energy intake) in both groups. In pregnant women with type 1 diabetes, the average total intake was 218 ± 19 g/day, which was 20% (53 g/day) lower than in healthy pregnant women. Mean intake of dietary fiber in women with diabetes was lower than the recommended adequate intake for healthy women. With the limitations of pronounced heterogeneity across the included studies, pregnant women with type 1 diabetes reported a mean total carbohydrate intake, which was lower than in healthy pregnant women but still within the recommended range.

Maternal Dietary Selenium Intake during Pregnancy Is Associated with Higher Birth Weight and Lower Risk of Small for Gestational Age Births in the Norwegian Mother, Father and Child Cohort Study

Selenium is an essential trace element involved in the body’s redox reactions. Low selenium intake during pregnancy has been associated with low birth weight and an increased risk of children being born small for gestational age (SGA). Based on data from the Norwegian Mother, Father and Child Cohort Study (MoBa) and the Medical Birth Registry of Norway (MBRN), we studied the association of maternal selenium intake from diet and supplements during the first half of pregnancy (n = 71,728 women) and selenium status in mid-pregnancy (n = 2628 women) with birth weight and SGA status, according to population-based, ultrasound-based and customized growth standards. An increase of one standard deviation of maternal dietary selenium intake was associated with increased birth weight z-scores (ß = 0.027, 95% CI: 0.007, 0.041) and lower SGA risk (OR = 0.91, 95% CI 0.86, 0.97) after adjusting for confounders. Maternal organic and inorganic selenium intake from supplements as well as whole blood selenium concentration were not associated with birth weight or SGA. Our results suggest that a maternal diet rich in selenium during pregnancy may be beneficial for foetal growth. However, the effect estimates were small and further studies are needed to elucidate the potential impact of selenium on foetal growth.

Insufficient maternal iodine intake is associated with subfecundity, reduced foetal growth, and adverse pregnancy outcomes in the Norwegian Mother, Father and Child Cohort Study

BACKGROUND

Severe iodine deficiency impacts fertility and reproductive outcomes. The potential effects of mild-to-moderate iodine deficiency are not well known. The aim of this study was to examine whether iodine intake was associated with subfecundity (i.e. > 12 months trying to get pregnant), foetal growth, and adverse pregnancy outcomes in a mild-to-moderately iodine-deficient population.

METHODS

We used the Norwegian Mother, Father and Child Cohort Study (MoBa) and included 78,318 pregnancies with data on iodine intake and pregnancy outcomes. Iodine intake was calculated using an extensive food frequency questionnaire in mid-pregnancy. In addition, urinary iodine concentration was available in a subsample of 2795 pregnancies. Associations were modelled continuously by multivariable regression controlling for a range of confounding factors.

RESULTS

The median iodine intake from food was 121 μg/day and the median urinary iodine was 69 μg/L, confirming mild-to-moderate iodine deficiency. In non-users of iodine supplements (n = 49,187), low iodine intake (< 100-150 μg/day) was associated with increased risk of preeclampsia (aOR = 1.14 (95% CI 1.08, 1.22) at 75 vs. 100 μg/day, p overall < 0.001), preterm delivery before gestational week 37 (aOR = 1.10 (1.04, 1.16) at 75 vs. 100 μg/day, p overall = 0.003), and reduced foetal growth (- 0.08 SD (- 0.10, - 0.06) difference in birth weight z-score at 75 vs. 150 μg/day, p overall < 0.001), but not with early preterm delivery or intrauterine death. In planned pregnancies (n = 56,416), having an iodine intake lower than ~ 100 μg/day was associated with increased prevalence of subfecundity (aOR = 1.05 (1.01, 1.09) at 75 μg/day vs. 100 μg/day, p overall = 0.005). Long-term iodine supplement use (initiated before pregnancy) was associated with increased foetal growth (+ 0.05 SD (0.03, 0.07) on birth weight z-score, p < 0.001) and reduced risk of preeclampsia (aOR 0.85 (0.74, 0.98), p = 0.022), but not with the other adverse pregnancy outcomes. Urinary iodine concentration was not associated with any of the dichotomous outcomes, but positively associated with foetal growth (n = 2795, p overall = 0.017).

CONCLUSIONS

This study shows that a low iodine intake was associated with restricted foetal growth and a higher prevalence of preeclampsia in these mild-to-moderately iodine-deficient women. Results also indicated increased risk of subfecundity and preterm delivery. Initiating iodine supplement use in pregnancy may be too late.

Maternal use of folic acid and multivitamin supplements and infant risk of birth defects in Norway, 1999-2013

The association between folic acid supplementation and birth defects other than neural tube defects (NTD) remains unclear. We used a log-binomial regression model to investigate if periconceptional folic acid and/or multivitamin use was associated with birth defects in Norway with prospectively collected data from the Medical Birth Registry of Norway (MBRN) during 1999-2013. We used the European Surveillance of Congenital Anomalies (EUROCAT) classification system to define eleven organ-specific major birth defect groups (nervous system, eye, ear-face-neck, cardiovascular system, respiratory system, oral clefts, digestive system, abdominal wall, urinary system, genital organs and limb), with additional subgroups. Fetuses or infants whose mothers used folic acid and/or multivitamin supplements before and during pregnancy were classified as exposed. During the years 1999-2013, 888 294 (99·0 %) live-born infants, 6633 (0·7 %) stillborn infants and 2135 (0·2 %) fetuses from terminated pregnancies due to fetal anomalies were registered in the MBRN. Among the live- and stillborn infants of women who used vitamin supplements compared with infants of non-users, the adjusted relative risk (aRR) was 0·94 (95 % CI 0·91, 0·98) for total birth defects (n 18 382). Supplement use was associated with reduced risk of abdominal wall defects (aRR 0·58; 95 % CI 0·42, 0·80, n 377), genital organ defects (aRR 0·81; 95 % CI 0·72, 0·91, n 2299) and limb defects (aRR 0·81; 95 % CI 0·74, 0·90, n 3409). Protective associations were also suggested for NTD, respiratory system defects and digestive system defects although CI included the null value of 1. During the full study period, statistically significant associations between supplement use and defects in the eye, ear-face-neck, heart or oral clefts were not observed.

Dietary Iron Intake in Pregnant Women in Europe: A Review of 24 Studies from 14 Countries in the Period 1991-2014

OBJECTIVE

Assessment of dietary iron intake in pregnant women in Europe.

DESIGN

Review. Setting. Literature search of dietary surveys reporting the intake of dietary iron using the PubMed and Google Scholar databases covering the years 1990-2019.

SUBJECTS

Healthy pregnant women.

RESULTS

24 dietary surveys/studies in 14 European countries were included. Nine studies (38%) used Food Frequency Questionnaires, which yielded significantly higher iron intake than studies using Dietary Records. Results from Dietary Record studies in 11 countries showed that iron intake varied between 8.3-15.4 mg/day with an estimated "median" value of 10-11 mg/day. Spain, Bosnia, and Poland reported an intake of 8.3-10.1 mg/day, Croatia, England, Norway, and Finland an intake of 10.2-11.4 mg/day, and Germany, Portugal, Czech Republic, and Greece an intake of 12.2-15.4 mg/day. The recommended iron intake in the various countries varied from 14.8-30 mg/day. In all studies, 60-100% of the women had a dietary iron intake below the recommended intake.

CONCLUSIONS

In Europe, the majority of pregnant women have a dietary iron intake, which is markedly below the recommended intake. This contributes to a low iron status in many pregnant women. Most guidelines do not advice routine iron supplements, while two guidelines (World Health Organization and Nordic Nutrition Recommendations) recommend routine iron supplementation during pregnancy. Within the European community, we need to reach consensus on the various guidelines and on the issue of iron supplementation. We should establish common European standardized dietary methods, uniform Dietary Reference Values, and uniform statistical methods in order to perform more reliable comparisons between studies in different countries.

Vitamin B12 concentrations in milk from Norwegian women during the six first months of lactation

BACKGROUND

Human milk vitamin B12 (B12) concentrations depend on maternal status and intake; only few data are available in high-income countries.

OBJECTIVE

We assessed human milk B12 concentrations during the first 6 months postpartum in Norwegian women and its association with maternal dietary B12 intake and maternal urinary methylmalonic acid (MMA) concentration.

METHODS

In this cross-sectional study, 175 mothers, exclusively (80%) or partially (20%) breastfeeding, were included. Milk B12 was measured by IMMULITE^®/IMMULITE^® 1000 B12 competitive protein binding assay and urinary MMA relative to creatinine (MMA/Cr) by liquid chromatography-tandem-mass spectrometry. Maternal habitual B12 intake and supplement use were estimated using a food frequency questionnaire.

RESULTS

Mean human milk B12 concentration was 327 pmol/L (range 140-1089), with 402 pmol/L at 1 month (n = 21), 333 pmol/L at four months (n = 32), and 299 pmol/L at 6 months (n = 21). Maternal B12 intake was 5 µg/d, 89% met the Estimated Average Requirement, and supplement use did not affect milk B12 concentrations. MMA/Cr was low in all women compared with published data. In exclusively breastfeeding women, MMA/Cr (beta (95% CI) -42.5 (-82.5, -2.5) and time since birth (-4.9 (-9.6, -0.3)) were significant predictors of human milk B12 concentrations. There was no association between total B12 intake and milk B12 concentration or between total B12 intake and MMA/Cr.

CONCLUSIONS

Maternal B12 status and human milk B12 concentrations are likely sufficient, based on adequate maternal B12 dietary intake combined with low urinary MMA concentrations. Nevertheless, milk B12 concentration fell during 6 months postpartum while maternal B12 status did not change.

Maternal dietary selenium intake is associated with increased gestational length and decreased risk of preterm delivery

The first positive genome-wide association study on gestational length and preterm delivery showed the involvement of an Se metabolism gene. In the present study, we examine the association between maternal intake of Se and Se status with gestational length and preterm delivery in 72 025 women with singleton live births from the population-based, prospective Norwegian Mother, Father and Child Cohort Study (MoBa). A self-reported, semi-quantitative FFQ answered in pregnancy week 22 was used to estimate Se intake during the first half of pregnancy. Associations were analysed with adjusted linear and Cox regressions. Se status was assessed in whole blood collected in gestational week 17 (n 2637). Median dietary Se intake was 53 (interquartile range (IQR) 44–62) µg/d, supplements provided additionally 50 (IQR 30–75) µg/d for supplement users (n 23 409). Maternal dietary Se intake was significantly associated with prolonged gestational length (β per sd = 0·25, 95 % CI, 0·07, 0·43) and decreased risk of preterm delivery (n 3618, hazard ratio per sd = 0·92, 95 % CI, 0·87, 0·98). Neither Se intake from supplements nor maternal blood Se status was associated with gestational length or preterm delivery. Hence, the present study showed that maternal dietary Se intake but not intake of Se-containing supplements, during the first half of pregnancy was significantly associated with decreased risk of preterm delivery. Further investigations, preferably in the form of a large randomised controlled trial, are needed to elucidate the impact of Se on pregnancy duration.

Food and nutrient intake and adherence to dietary recommendations during pregnancy: a Nordic mother-child population-based cohort

Background

A woman's food intake during pregnancy has important implications not only for herself but also for the future health and well-being of her child. Suboptimal dietary quality has been consistently reported in many high-income countries, reflecting poor adherence to dietary guidelines.

Objective

This study aimed to explore the intake of food and nutrients in a cohort of pregnant women in Norway and their adherence to Nordic Nutrition Recommendations (NNR) and Norwegian food-based guidelines (NFG).

Design

We investigated the dietary intake in 1,674 pregnant women from the mother-child birth cohort, PreventADALL, recruited at approximately 18-week gestational age. Dietary intake was assessed by an electronic validated food frequency questionnaire (PrevFFQ) in the first half of pregnancy.

Results

Total fat intake was within the recommended intake (RI) range in most women; however, the contribution of saturated fatty acids to the total energy intake was above RI in the majority (85.2%) of women. Carbohydrate intake was below RI in 43.9% of the women, and 69.5% exceeded the RI of salt. Intakes of fiber, vegetables, and fish were high in a large part of the population. Many women had a high probability of inadequate intakes of the following key micronutrients during pregnancy: folate (54.4%), iron (49.6%), calcium (36.2%), vitamin D (28.7%), iodine (24.4%), and selenium (41.3%). A total of 22.8% women reported an alcohol intake of >1 g/day, and 4.4% reported an alcohol intake of >10 g/day. Women with higher educational levels showed a tendency towards healthier eating habits, except for higher intakes of alcohol and coffee, compared to women with lower educational level.

Discussion

Excessive saturated fat intake and limited intake of many important micronutrients during pregnancy were common, potentially increasing the risk for adverse pregnancy and birth outcomes.

Conclusions

This study highlights the need for improved nutritional guidance to pregnant women across all educational levels.

Maternal serum retinol, 25(OH)D and 1,25(OH)2D concentrations during pregnancy and peak bone mass and trabecular bone score in adult offspring at 26-year follow-up

Background

Vitamin A and D deficiency is prevalent in pregnant women worldwide. Both vitamins are involved in fetal skeletal development. A positive association between maternal vitamin D levels and offspring bone mineral density (BMD) at adulthood has been observed. The impact of maternal vitamin A status in pregnancy on offspring peak bone mass remains unclear.

Method and findings

Forty-one mother-child pairs were recruited from a population-based prospective cohort study in Trondheim, Norway, where pregnant women were followed from gestational week 17. Their term-born infants were followed from birth (1986–88). Regression analyses were performed for vitamin A (retinol), 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)₂D] in maternal serum (gestational weeks 17, 33, 37) and cord blood. Offspring BMD and spine trabecular bone score (TBS), a measure of bone quality, were analyzed by dual x-ray absorptiometry at 26 years. Average levels during pregnancy of retinol, 25(OH)D and 1,25(OH)₂D were 1.66 (0.32) μmol/L, 59.0 (20.6) nmol/L, and 251.3 (62.4) pmol/L, respectively. 1,25(OH)₂D levels were similar in those with 25(OH)D levels <30 and >75 nmol/L. After adjustment for maternal age, BMI, smoking, and education, and offspring birth weight, maternal serum retinol was positively associated with offspring spine BMD [mean change 30.8 (CI 7.6, 54.0) mg/cm² per 0.2 μmol/L retinol], and with offspring TBS, although non-significant (p = 0.08). No associations were found between maternal 25(OH)D and 1,25(OH)₂D levels and offspring bone parameters. Vitamin levels in cord blood were not associated with offspring BMD or TBS.

Conclusions

This is the first study to show an association between maternal vitamin A status and offspring peak bone mass. Our findings may imply increase future risk for osteoporotic fracture in offspring of mothers with suboptimal vitamin A level. No associations were observed between 25(OH)D and 1,25(OH)₂D and offspring BMD.

Patterns and dietary determinants of essential and toxic elements in blood measured in mid-pregnancy: The Norwegian Environmental Biobank

BACKGROUND

Inadequate stores or intakes of essential minerals in pregnancy, or too high exposure to both toxic and essential elements, can have adverse effects on mother and child. The main aims of this study were to 1) describe the concentrations and patterns of essential and toxic elements measured in maternal whole blood during pregnancy; 2) identify dietary, lifestyle and sociodemographic determinants of element status; and 3) explore the impact of iron deficiency on blood element concentrations.

METHODS

This study is based on blood samples collected from 2982 women in gestational week 18 in The Norwegian Mother and Child Cohort study (MoBa) which were analyzed as part of the Norwegian Environmental Biobank. We derived blood element patterns by exploratory factor analysis, and associations between blood element patterns and diet were explored using sparse partial least squares (sPLS) regression.

RESULTS

Blood concentrations were determined for the essential elements (in the order of most abundant) Zn > Cu > Se > Mn > Mo > Co, and the toxic metals Pb > As > Hg > Cd > Tl. The concentrations were in ranges that were similar to or sometimes more favorable than in other pregnant and non-pregnant European women. We identified two blood element patterns; one including Zn, Se and Mn and another including Hg and As. For the Zn-Se-Mn pattern, use of multimineral supplements was the most important dietary determinant, while a high score in the Hg-As pattern was mainly determined by seafood consumption. Concentrations of Mn, Cd and Co were significantly higher in women with iron deficiency (plasma ferritin < 12 μg/L) than in women with plasma ferritin ≥ 12 μg/L.

CONCLUSION

Our study illustrates complex relationships and coexistence of essential and toxic elements. Their potential interplay adds to the challenges of studies investigating health effects related to either diet or toxicants.

Maternal and Newborn Vitamin D-Binding Protein, Vitamin D Levels, Vitamin D Receptor Genotype, and Childhood Type 1 Diabetes

OBJECTIVE

Circumstantial evidence links 25-hydroxy vitamin D [25(OH)D], vitamin D-binding protein (DBP), vitamin D-associated genes, and type 1 diabetes (T1D), but no studies have jointly analyzed these. We aimed to investigate whether DBP levels during pregnancy or at birth were associated with offspring T1D and whether vitamin D pathway genetic variants modified associations between DBP, 25(OH)D, and T1D.

RESEARCH DESIGN AND METHODS

From a cohort of >100,000 mother/child pairs, we analyzed 189 pairs where the child later developed T1D and 576 random control pairs. We measured 25(OH)D using liquid chromatography-tandem mass spectrometry, and DBP using polyclonal radioimmunoassay, in cord blood and maternal plasma samples collected at delivery and midpregnancy. We genotyped mother and child for variants in or near genes involved in vitamin D metabolism (GC, DHCR7, CYP2R1, CYP24A1, CYP27B1, and VDR). Logistic regression was used to estimate odds ratios (ORs) adjusted for potential confounders.

RESULTS

Higher maternal DBP levels at delivery, but not in other samples, were associated with lower offspring T1D risk (OR 0.86 [95% CI 0.74-0.98] per μmol/L increase). Higher cord blood 25(OH)D levels were associated with lower T1D risk (OR = 0.87 [95% CI 0.77-0.98] per 10 nmol/L increase) in children carrying the VDR rs11568820 G/G genotype (P _interaction = 0.01 between 25(OH)D level and rs11568820). We did not detect other gene-environment interactions.

CONCLUSIONS

Higher maternal DBP level at delivery may decrease offspring T1D risk. Increased 25(OH)D levels at birth may decrease T1D risk, depending on VDR genotype. These findings should be replicated in other studies. Future studies of vitamin D and T1D should include VDR genotype and DBP levels.

Global inequities in dietary calcium intake during pregnancy: a systematic review and meta-analysis

BACKGROUND

Evidence shows that adequate calcium intake during pregnancy reduces the risk of hypertensive disorders of pregnancy. In most low- and middle-income countries (LMICs) the daily calcium intake is well below recommendations. Mapping calcium intake during pregnancy worldwide and identifying populations with low calcium intake will provide the evidence base for more targeted actions to improve calcium intake.

OBJECTIVE

To assess dietary calcium intake during pregnancy worldwide.

SEARCH STRATEGY

MEDLINE and EMBASE (from July 2004 to November 2017).

SELECTION CRITERIA

Cross-sectional, cohort, and intervention studies reporting calcium intake during pregnancy.

DATA COLLECTION AND ANALYSIS

Five reviewers working in pairs independently performed screening, extraction, and quality assessment. We reported summary measures of calcium intake and calculated the weighted arithmetic mean for high-income countries (HICs) and LMICs independently, and for geographic regions, among studies reporting country of recruitment, mean intake, and total number of participants. When available, inadequate intakes were reported.

MAIN RESULTS

From 1880 citations 105 works met the inclusion criteria, providing data for 73 958 women in 37 countries. The mean calcium intake was 948.3 mg/day (95% CI 872.1-1024.4 mg/day) for HICs and 647.6 mg/day (95% CI 568.7-726.5 mg/day) for LMICs. Calcium intakes below 800 mg/day were reported in five (29%) countries from HICs and in 14 (82%) countries from LMICs.

CONCLUSION

These results are consistent with a lack of improvement in calcium dietary intake during pregnancy and confirm the gap between HICs and LMICs, with alarmingly low intakes recorded for pregnant women in LMICs. From the public health perspective, in the absence of specific local data, calcium supplementation of pregnant women in these countries should be universal.

TWEETABLE ABSTRACT

Despite dietary recommendations, women in LMICs face pregnancy with diets low in calcium.

Micronutrient supplementation in pregnancy: Who, what and how much?

Pregnancy represents a period of major physiological and metabolic change, aiming to ensure proper fetal growth and development, as well as maternal preservation. This review focuses on maternal nutrition, and particularly on micronutrient deficiencies and supplementation during pregnancy. Nutrient deficiencies and consequences in pregnant women are presented, with an overview of current recommendations for dietary supplementation in pregnancy, even considering the risk of micronutrient overload. Appropriate universal supplementation and prophylaxis/treatment of nutritional needs currently appear to be the most cost-effective goal in low-income countries, thus ensuring adequate intake of key elements including folate, iron, calcium, vitamin D and A. In high-income countries, a proper nutritional assessment and counselling should be mandatory in obstetric care in order to normalize pregestational body mass index, choose a healthy dietary pattern and evaluate the risk of deficiencies.

Language delay and poorer school performance in children of mothers with inadequate iodine intake in pregnancy: results from follow-up at 8 years in the Norwegian Mother and Child Cohort Study

Purpose

Some studies indicate that mild-to-moderate iodine deficiency in pregnant women might negatively affect offspring neurocognitive development, including previous results from the Norwegian Mother and Child Cohort study (MoBa) exploring maternally reported child development at age 3 years. The aim of this follow-up study was to investigate whether maternal iodine intake in pregnancy is associated with language and learning at 8 years of age.

Methods

The study sample includes 39,471 mother–child pairs participating in MoBa with available information from a validated food frequency questionnaire covering the first half of pregnancy and a questionnaire on child neurocognitive development at 8 years. Multivariable regression was used to explore associations of iodine intake from food and supplements with maternally reported child outcomes.

Results

Maternal iodine intake from food less than ~ 150 µg/day was associated with poorer child language skills (p-overall = 0.013), reading skills (p-overall = 0.019), and writing skills (p-overall = 0.004) as well as poorer school test result in reading (p < 0.001), and increased likelihood of the child receiving special educational services (p-overall = 0.042) (in non-iodine supplement users). Although significant, differences were generally small. Maternal use of iodine supplements in pregnancy was not significantly associated with any of the outcomes.

Conclusions

Low habitual iodine intake in pregnant women, i.e., lower than the recommended intake for non-pregnant women, was associated with mothers reporting poorer child language, school performance, and increased likelihood of special educational services. We found no indications of benefits or harm of using iodine-containing supplements in pregnancy. Initiating use in pregnancy might be too late.

Electronic supplementary material

The online version of this article (10.1007/s00394-018-1850-7) contains supplementary material, which is available to authorized users.

Iodine Intake is Associated with Thyroid Function in Mild to Moderately Iodine Deficient Pregnant Women

BACKGROUND

Studies indicate that mild to moderate iodine deficiency in pregnancy may have a long-term negative impact on child neurodevelopment. These effects are likely mediated via changes in maternal thyroid function, since iodine is essential for the production of thyroid hormones. However, the impact of iodine availability on thyroid function during pregnancy and on thyroid function reference ranges are understudied. The aim of this study was to investigate the association between iodine intake and thyroid function during pregnancy.

DESIGN

In a population-based pregnancy cohort including 2910 pregnant women participating in The Norwegian Mother and Child Cohort Study, we explored cross sectional associations of maternal iodine intake measured (1) by a food frequency questionnaire and (2) as iodine concentration in a spot urine sample, with plasma thyroid hormones and antibodies.

RESULTS

Biological samples were collected in mean gestational week 18.5 (standard deviation 1.3) and diet was assessed in gestational week 22. Median iodine intake from food was 121 μg/day (interquartile range 90, 160), and 40% reported use of iodine-containing supplements in pregnancy. Median urinary iodine concentration (UIC) was 59 μg/L among those who did not use supplements and 98 μg/L in the women reporting current use at the time of sampling, indicating mild to moderate iodine deficiency in both groups. Iodine intake as measured by the food frequency questionnaire was not associated with the outcome measures, while UIC was inversely associated with FT3 (p = 0.002) and FT4 (p < 0.001). Introduction of an iodine-containing supplement after gestational week 12 was associated with indications of lower thyroid hormone production (lower FT4, p = 0.027, and nonsignificantly lower FT3, p = 0.17). The 2.5th and 97.5th percentiles of TSH, FT4, and FT3 were not significantly different by groups defined by calculated iodine intake or by UIC.

CONCLUSION

The results indicate that mild to moderate iodine deficiency affect thyroid function in pregnancy. However, the differences were small, suggesting that normal reference ranges can be determined based on data also from mildly iodine deficient populations, but this needs to be further studied. Introducing an iodine-containing supplement might temporarily inhibit thyroid hormone production and/or release.

Maternal Serum Cobalamin at 18 Weeks of Pregnancy Predicts Infant Cobalamin Status at 6 Months-A Prospective, Observational Study

Background

An adequate maternal cobalamin status is crucial for fetal and infant neurodevelopment. Pregnancy-induced physiologic changes make evaluation of maternal cobalamin status in pregnancy difficult.

Objective

We have investigated maternal cobalamin status during pregnancy in order to establish a maternal cobalamin concentration which secures an optimal infant cobalamin status during the first 6 mo of life.

Methods

In an observational, prospective study, markers of cobalamin status including serum cobalamin, plasma total homocysteine (tHcy), and plasma methylmalonic acid (MMA) were assessed in healthy pregnant women (n = 114) from week 18 of pregnancy through 6 mo postpartum and related to infant cobalamin status at 6 mo. Healthy, never-pregnant women aged 18-40 y (n = 123) were included as controls.

Results

Compared to controls, all markers of cobalamin status were lower in pregnant women. Median serum cobalamin concentration progressively decreased from week 18 to week 36 of pregnancy (356 to 302 pmol/L, P < 0.001) and increased by >40% by 6 wk postpartum (518 pmol/L). The metabolic markers increased from week 18 of pregnancy to 6 wk postpartum: median plasma tHcy 3.9 to 7.7 μmol/L (P < 0.001), and MMA 0.13 to 0.17 μmol/L (P < 0.001). The serum cobalamin concentration of infants at age 6 mo correlated with maternal serum cobalamin concentration during pregnancy and postpartum (rho = 0.36-0.55, P < 0.001). A maternal serum cobalamin concentration <394 pmol/L during week 18 of pregnancy was associated with an increased risk (OR: 4.2; 95% CI: 1.5, 11.5) of infant biochemical cobalamin deficiency at 6 mo (defined as tHcy ≥6.5 μmol/L).

Conclusions

The maternal serum cobalamin concentration in early pregnancy is a strong predictor for later maternal and infant cobalamin status. To secure an optimal infant cobalamin status during the first 6 mo of life, we recommend a maternal serum cobalamin concentration >394 pmol/L at week 18 of pregnancy. This should be confirmed in an intervention study. This trial was registered at clinicaltrials.gov as NCT03272022.

Vitamin A and D intake in pregnancy, infant supplementation, and asthma development: the Norwegian Mother and Child Cohort

Background

Western diets may provide excess vitamin A, which is potentially toxic and could adversely affect respiratory health and counteract benefits from vitamin D.

Objective

The aim of this study was to examine child asthma at age 7 y in relation to maternal intake of vitamins A and D during pregnancy, infant supplementation with these vitamins, and their potential interaction.

Design

We studied 61,676 school-age children (born during 2002-2007) from the Norwegian Mother and Child Cohort with data on maternal total (food and supplement) nutrient intake in pregnancy (food-frequency questionnaire validated against biomarkers) and infant supplement use at age 6 mo (n = 54,142 children). Linkage with the Norwegian Prescription Database enabled near-complete follow-up (end of second quarter in 2015) for dispensed medications to classify asthma. We used log-binomial regression to calculate adjusted RRs (aRRs) for asthma with 95% CIs.

Results

Asthma increased according to maternal intake of total vitamin A [retinol activity equivalents (RAEs)] in the highest (≥2031 RAEs/d) compared with the lowest (≤779 RAEs/d) quintile (aRR: 1.21; 95% CI: 1.05, 1.40) and decreased for total vitamin D in the highest (≥13.6 µg/d) compared with the lowest (≤3.5 µg/d) quintile (aRR: 0.81; 95% CI: 0.67, 0.97) during pregnancy. No association was observed for maternal intake in the highest quintiles of both nutrients (aRR: 0.99; 95% CI: 0.83, 1.18) and infant supplementation with vitamin D or cod liver oil.

Conclusions

Excess vitamin A (≥2.5 times the recommended intake) during pregnancy was associated with increased risk, whereas vitamin D intake close to recommendations was associated with a reduced risk of asthma in school-age children. No association for high intakes of both nutrients suggests antagonistic effects of vitamins A and D. This trial was registered at http://www.clinicaltrials.gov as NCT03197233.

Risk factors for discontinuation of thyroid hormone replacement therapy in early pregnancy: a study from the Norwegian Mother and Child Cohort Study and the Medical Birth Registry of Norway

INTRODUCTION

Approximately 3-5% of pregnant women have hypothyroidism. Despite the potential impact of untreated hypothyroidism on infant neurodevelopment, few studies have investigated the risk factors associated with discontinuation of thyroid hormone replacement therapy (THRT) in pregnancy. We aimed to identify such factors in a population of women using THRT prior to pregnancy.

MATERIAL AND METHODS

Data from the Norwegian Mother and Child Cohort Study were linked to records in the Medical Birth Registry of Norway. Pregnant women with hypothyroidism prior to pregnancy were categorized as discontinuers or continuers of THRT in pregnancy. The main analysis used generalized estimating equations based on multiply imputed data.

RESULTS

Of 86 848 enrolled pregnant women, 2720 (3.2%) had a medically confirmed thyroid disorder and/or reported use of thyroid therapy. More than half (n = 1587; 57.8%) used THRT prior to pregnancy; of these, 207 (13.0%) discontinued and 1380 (86.9%) continued THRT during early pregnancy. Having a non-medicated mental disorder [odds ratio (OR) 1.64, 95% CI 1.03-2.63] and non-compliance with recommended nutritional supplementation (OR 2.51, 95% CI 1.82-3.47) increased the odds of discontinuing THRT. Women medicated for somatic comorbidities (OR 0.56, 95% CI 0.33-0.98) had a 44% decreased odds of discontinuing THRT.

CONCLUSIONS

In Norway, around 13% of women with hypothyroidism discontinue THRT in early pregnancy. For discontinuers, non-medicated mental comorbidity and non-compliance with nutritional supplements presented increased risk, whereas having a medicated somatic disorder was protective. Health professionals advising women with hypothyroidism should be aware of risk factors associated with THRT discontinuation.

Timing of probiotic milk consumption during pregnancy and effects on the incidence of preeclampsia and preterm delivery: a prospective observational cohort study in Norway

OBJECTIVES

To investigate whether the timing of probiotic milk intake before, during early or late pregnancy influences associations with preeclampsia and preterm delivery.

DESIGN

Population based prospective cohort study.

SETTING

Norway, between 1999 and 2008.

PARTICIPANTS

70 149 singleton pregnancies resulting in live-born babies from the Norwegian Mother and Child Cohort Study (no chronic disease, answered questionnaires, no placenta previa/cerclage/serious malformation of fetus, first enrolment pregnancy). Only nulliparous women (n=37 050) were included in the preeclampsia analysis. Both iatrogenic and spontaneous preterm delivery (between gestational weeks 22+0 and 36+6) with spontaneous term controls (between gestational weeks 39+0 and 40+6) were included in the preterm delivery analysis resulting in 34 458 cases.

MAIN OUTCOME MEASURES

Adjusted OR for preeclampsia and preterm delivery according to consumption of probiotic milk at three different time periods (before pregnancy, during early and late pregnancy).

RESULTS

Probiotic milk intake in late pregnancy (but not before or in early pregnancy) was significantly associated with lower preeclampsia risk (adjusted OR: 0.80 (95% CI 0.68 to 0.94) p-value: 0.007). Probiotic intake during early (but not before or during late pregnancy) was significantly associated with lower risk of preterm delivery (adjusted OR: 0.79 (0.64 to 0.97) p-value: 0.03).

CONCLUSIONS

In this observational study, we found an association between timing of probiotic milk consumption during pregnancy and the incidence of the adverse pregnancy outcomes preeclampsia and preterm delivery. If future randomised controlled trials could establish a causal association between probiotics consumption and reduced risk of preeclampsia and preterm delivery, recommending probiotics would be a promising public health measure to reduce these adverse pregnancy outcomes.

Development of Databases on Iodine in Foods and Dietary Supplements

Iodine is an essential micronutrient required for normal growth and neurodevelopment; thus, an adequate intake of iodine is particularly important for pregnant and lactating women, and throughout childhood. Low levels of iodine in the soil and groundwater are common in many parts of the world, often leading to diets that are low in iodine. Widespread salt iodization has eradicated severe iodine deficiency, but mild-to-moderate deficiency is still prevalent even in many developed countries. To understand patterns of iodine intake and to develop strategies for improving intake, it is important to characterize all sources of dietary iodine, and national databases on the iodine content of major dietary contributors (including foods, beverages, water, salts, and supplements) provide a key information resource. This paper discusses the importance of well-constructed databases on the iodine content of foods, beverages, and dietary supplements; the availability of iodine databases worldwide; and factors related to variability in iodine content that should be considered when developing such databases. We also describe current efforts in iodine database development in the United States, the use of iodine composition data to develop food fortification policies in New Zealand, and how iodine content databases might be used when considering the iodine intake and status of individuals and populations.

Sociodemographic factors associated with dietary supplement use in early pregnancy in a Swedish cohort

Sociodemographic factors have been associated with dietary supplement use among pregnant women but few data exist in a Swedish population. This study aimed to identify factors associated with overall supplement use as well as use of folic acid, vitamin D and n-3 in early pregnancy. Women in the first trimester of pregnancy were included at registration to the antenatal care in 2013-2014 (n 2109). Information regarding supplement use as well as sociodemographic and anthropometric data were obtained from questionnaires and medical records. Multivariable logistic regression analysis was performed to determine the relationship between sociodemographic variables and supplement use. A total of 78 % of the participants reported using at least one dietary supplement in the first trimester. Folic acid supplement use was reported by 74 %, vitamin D supplement use by 43 % and n-3 supplement use by <5 %. Use of any type of supplement in early pregnancy was related to gestational age, parity, birthplace, education and employment. Folic acid supplement use was related to gestational age, parity, birthplace, income, education and employment. Vitamin D supplement use was related to gestational age, birthplace and education. In conclusion, in the first trimester of pregnancy, folic acid supplements were used by three in four women, while vitamin D supplements were used by less than half of the women. The results of this study show a socioeconomic disparity between supplement users and non-users which may have a negative impact on the health of future generations.

Maternal Iodine Intake and Offspring Attention-Deficit/Hyperactivity Disorder: Results from a Large Prospective Cohort Study

Current knowledge about the relationship between mild to moderately inadequate maternal iodine intake and/or supplemental iodine on child neurodevelopment is sparse. Using information from 77,164 mother-child pairs in the Norwegian Mother and Child Cohort Study, this study explored associations between maternal iodine intake and child attention-deficit/hyperactivity disorder (ADHD) diagnosis, registered in the Norwegian Patient Registry and maternally-reported child ADHD symptoms at eight years of age. Pregnant women reported food and supplement intakes by questionnaire in gestational week 22. In total, 1725 children (2.2%) were diagnosed with ADHD. In non-users of supplemental iodine (53,360 mothers), we found no association between iodine intake from food and risk of child ADHD diagnosis (p = 0.89), while low iodine from food (<200 µg/day) was associated with higher child ADHD symptom scores (adjusted difference in score up to 0.08 standard deviation (SD), p < 0.001, n = 19,086). In the total sample, we found no evidence of beneficial effects of maternal use of iodine-containing supplements (n = 23,804) on child ADHD diagnosis or symptom score. Initiation of iodine supplement use in gestational weeks 0-12 was associated with an increased risk of child ADHD (both measures). In conclusion, insufficient maternal iodine intake was associated with increased child ADHD symptom scores at eight years of age, but not with ADHD diagnosis. No reduction of risk was associated with maternal iodine supplement use.

Fetal and Maternal Genetic Variants Influencing Neonatal Vitamin D Status

OBJECTIVE

Several genetic polymorphisms determine vitamin D status. We aimed to estimate the strength of association of established 25-hydroyxvitamin D (25OHD)-associated variants in the mother and in the fetus, with 25OHD concentration in newborn umbilical cord plasma.

METHODS

We randomly selected 578 mother and child dyads from the prospective Norwegian Mother and Child Cohort study. 25OHD was assayed in maternal samples taken shortly after delivery and in cord samples. We genotyped the mother and child for single nucleotide polymorphisms in or near GC, DHCR7, CYP2R1, and CYP24A1, previously confirmed to be associated with 25OHD, and computed genetic risk score (GRS). The genetic associations were replicated in an independent sample of 594 subjects.

RESULTS

Although both fetal and maternal GRS were associated with cord 25OHD, only fetal GRS remained significantly associated with cord 25OHD in a regression model with maternal and fetal GRS simultaneously (1.6 nmol/L per fetal 25OHD-increasing allele; 95% confidence interval, 0.6 to 2.5, P = 0.0001). Two fetal single nucleotide polymorphisms in the GC gene (rs2282679 and rs222040) were the strongest genetic predictors of cord 25OHD [4.0 (2.1 to 5.9) and 3.0 (1.3 to 4.8) nmol/L per fetal allele, P < 0.001], followed by rs12785878 in DHCR7 [2.0 (0.1 to 3.8) nmol/L, P = 0.037]. The independent replication sample gave similar results. With fetal genotype included in a regression model with environmental factors, R2 for cord 25OHD was 0.28.

CONCLUSIONS

We show that fetal 25OHD-modifying genotype was a stronger predictor of cord 25OHD than corresponding maternal genotype. This raises interesting questions about fetal acquisition and placental transfer of 25OHD.

Antenatal nutritional supplementation and autism spectrum disorders in the Stockholm youth cohort: population based cohort study

Objective To determine whether nutritional supplementation during pregnancy is associated with a reduced risk of autism spectrum disorder (ASD) with and without intellectual disability in offspring.Design Observational prospective cohort study using multivariable logistic regression, sibling controls, and propensity score matching.Setting Stockholm County, Sweden.Participants 273 107 mother-child pairs identified through population registers. The study sample was restricted to children who were aged 4 to 15 years by the end of follow-up on 31 December 2011 and were born between 1996 and 2007.Exposures Multivitamin, iron, and folic acid supplement use was reported at the first antenatal visit.Main outcome measure Diagnosis of ASD with and without intellectual disability in children determined from register data up to 31 December 2011.Results Prevalence of ASD with intellectual disability was 0.26% (158 cases in 61 934) in the maternal multivitamin use group and 0.48% (430 cases in 90 480) in the no nutritional supplementation use group. Maternal multivitamin use with or without additional iron or folic acid, or both was associated with lower odds of ASD with intellectual disability in the child compared with mothers who did not use multivitamins, iron, and folic acid (odds ratio 0.69, 95% confidence interval 0.57 to 0.84). Similar estimates were found in propensity score matched (0.68, 0.54 to 0.86) and sibling control (0.77, 0.52 to 1.15) matched analyses, though the confidence interval for the latter association included 1.0 and was therefore not statistically significant. There was no consistent evidence that either iron or folic acid use were inversely associated with ASD prevalence.Conclusions Maternal multivitamin supplementation during pregnancy may be inversely associated with ASD with intellectual disability in offspring. Further scrutiny of maternal nutrition and its role in the cause of autism is recommended.

Factors associated with dietary supplement use in Saudi pregnant women

Background

The aim was to investigate the prevalence of dietary supplement use among pregnant Saudi women and its associations between various demographics.

Methods

In this cross-sectional study, a total of 137 pregnant women attending prenatal care from King Salman Hospital completed a self-administered questionnaire including socio-demographic characteristics, general awareness, attitude and behavior towards use of dietary supplements during pregnancy.

Results

Dietary supplement use among Saudi women in pregnancy was high (71.5%) and was significantly associated with level of education (p = 0.005), family income (p = 0.039) and number of children (p = 0.007). No significant association was observed between neonatal health outcomes and dietary supplement use during pregnancy. In all participants, 81.6% believed that supplement use is important for nutritional status and more favorable neonatal outcomes. For the majority of participants, the primary source of information for dietary supplement use was a doctor’s advice. The majority of the participants [65.7% (n = 90)] responded that dietary supplement use is safe. Folic acid was found to be the most common type of dietary supplement used (95.9%; n = 94); however, 53.1% (n = 52) did not take folic acid supplements 3 months prior to pregnancy. Other common supplements used were iron, calcium and vitamin D (88.8, 81.6, and 41%, respectively).

Conclusions

This study provided new information on dietary supplement use and its correlates in Saudi pregnant women. The prevalence of dietary supplement use was high in this group and was associated with socio-demographic and lifestyle characteristics.

The impact of folic acid supplementation on gestational and long term health: Critical temporal windows, benefits and risks

Highlights

Associations between FA supplementation in pregnancy and effects on offspring's NTDs, allergy/respiratory problems, cancer and behaviour problems as been studied.There is growing concern about the effects of excessive FA supplementation, whether in terms of doses or times of exposure.FA supplementation in the periconceptional period is protective against NTDs while in later periods it could be deleterious.A daily dose of 0.4 mg FA in the periconceptional period seems to be effective and safe.

Abstract

Maternal folic acid (FA) supplementation is one of the most popular nutritional interventions during pregnancy for its protective effect against neural tube defects (NTDs).The purposes of this review are: (a) to gather the current evidence regarding supplementation of maternal diet with FA and (b) to problematize the available literature in terms of dosages, critical temporal windows, and its potential benefits and risks.The expression (pregnancy OR fetus OR offspring OR mother) AND ("folic acid" AND supplementation) was searched on PubMed database, filtering for articles published from 2005 to 2014. Publications referring to FA supplementation during the periconceptional period or pregnancy in which there was a conclusion about the effects of isolated FA supplementation on pregnant woman, pregnancy or offspring were included. Of the initial 1182 papers, 109 fulfilled the inclusion criteria.The majority of the publications reported FA supplementation outcomes on offspring's health, with emphasis in NTDs, allergy/respiratory problems, cancer and behaviour problems. Some inconsistency is observed on the impact of FA supplementation on different outcomes, except for NTDs. It is also visible an increased concern about the impact of excessive supplementation, either in terms of doses or exposure's duration.In conclusion, there is a growing interest in FA supplementation issues. The protective effect of FA supplementation over NTDs has been confirmed, being the periconceptional period a critical window, and it is frequently suggested that allergy/respiratory outcomes arise from (excessive) FA supplementation particularly later in pregnancy. Further research on critical doses and time of exposure should be conducted.

Maternal and neonatal vitamin D status, genotype and childhood celiac disease

Background

Low concentration of 25-hydroxyvitamin D during pregnancy may be associated with offspring autoimmune disorders. Little is known about environmental triggers except gluten for celiac disease, a common immune-mediated disorder where seasonality of birth has been reported as a risk factor. We therefore aimed to test whether low maternal and neonatal 25-hydroxyvitamin D predicted higher risk of childhood celiac disease.

Methods and Findings

In this Norwegian nationwide pregnancy cohort (n = 113,053) and nested case-control study, we analyzed 25-hydroxyvitamin D in maternal blood from mid-pregnancy, postpartum and cord plasma of 416 children who developed celiac disease and 570 randomly selected controls. Mothers and children were genotyped for established celiac disease and vitamin D metabolism variants. We used mixed linear regression models and logistic regression to study associations.

There was no significant difference in average 25-hydroxyvitamin D between cases and controls (63.1 and 62.1 nmol/l, respectively, p = 0.28), and no significant linear trend (adjusted odds ratio per 10 nM increase 1.05, 95% CI: 0.93–1.17). Results were similar when analyzing the mid-pregnancy, postpartum or cord plasma separately. Genetic variants for vitamin D deficiency were not associated with celiac disease (odds ratio per risk allele of the child, 1.00; 95% CI, 0.90 to 1.10, odds ratio per risk allele of the mother 0.94; 95% CI 0.85 to 1.04). Vitamin D intake in pregnancy or by the child in early life did not predict later celiac disease. Adjustment for established genetic risk markers for celiac disease gave similar results.

Conclusions

We found no support for the hypothesis that maternal or neonatal vitamin D status is related to the risk of childhood celiac disease.

Consumption of dietary supplements by Chinese women during pregnancy and postpartum: A prospective cohort study

The objectives of this study were to investigate usage patterns and factors associated with maternal dietary supplementation by Chinese women. A prospective cohort study of 695 mothers, who gave birth to a singleton baby, was conducted in Jiangyou, Sichuan Province of China. Information on dietary supplement use was collected from participants by personal interview at hospital discharge and followed up by telephone at 1, 3, and 6 months postpartum. Logistic regression analysis and generalised linear-mixed modelling were performed to determine factors affecting dietary supplementation during pregnancy and the first 6 months postpartum, respectively. A total of 81.8 and 32.1% of women consumed dietary supplements during pregnancy and postpartum, respectively. Calcium was the most popular supplement (pregnancy 63.9%; postpartum 28.1%), whereas folic acid was only taken during pregnancy (62.3%) with an average usage duration of 2.5 (standard deviation 1.3) months among users. High school and above education, adjusted odds ratio (OR) = 2.67, 95% confidence interval (CI) [1.63, 4.38], and attendance at prenatal classes (adjusted OR = 1.99, 95% CI [1.05, 3.76]) were associated with dietary supplementation during pregnancy. Mothers with a higher level of education (adjusted OR = 3.10, 95% CI [1.81, 5.30]) were also more likely to use dietary supplements in the postpartum period. Although dietary supplementation appeared to be common among Chinese mothers, maternal intake of folic acid was well below the guidelines. There is a need for further nutrition education on maternal use of micronutrient supplements, especially targeting mothers who are less educated.

Micronutrient Intake Is Inadequate for a Sample of Pregnant African-American Women

BACKGROUND

Micronutrient intake is critical for fetal development and positive pregnancy outcomes. Little is known about the adequacy of micronutrient intake in pregnant African-American women.

OBJECTIVE

To describe nutrient sufficiency and top food groups contributing to dietary intake of select micronutrients in low-income pregnant African-American women and determine whether micronutrient intake varies with early pregnancy body mass index (BMI) and/or gestational weight gain.

DESIGN

Secondary analysis of data collected in a cohort study of pregnant African-American women.

PARTICIPANTS/SETTING

A total of 93 women aged 18 to 36 years, <20 weeks pregnant, with early pregnancy BMIs ≥18.5 and <40.0. The study was conducted during 2008 to 2012 with participants from university-affiliated obstetrics clinics in an urban setting in the northeastern United States.

MAIN OUTCOME MEASURES

Proportion of women with dietary intakes below Estimated Average Requirement (EAR) or Adequate Intake (AI) for vitamin D, folate, iron, calcium, and choline throughout pregnancy. Top food groups from which women derived these micronutrients was also determined.

STATISTICAL ANALYSES PERFORMED

Descriptive statistics included means, standard deviations, and percentages. Percent of women reaching EAR or AI was calculated. The χ² test was used to assess micronutrient intake differences based on early pregnancy BMI and gestational weight gain.

RESULTS

A large percentage of pregnant women did not achieve the EAR or AI from dietary sources alone; EAR for folate (66%), vitamin D (100%), iron (89%), and AI for choline (100%). Mean micronutrient intake varied throughout pregnancy. Top food sources included reduced-fat milk, eggs, and mixed egg dishes, pasta dishes, and ready-to-eat cereal.

CONCLUSIONS

The majority of study participants had dietary micronutrient intake levels below EAR/AI throughout pregnancy. Findings suggest that practitioners should evaluate dietary adequacy in women to avoid deficits in micronutrient intake during pregnancy. Top food sources of these micronutrients can be considered when assisting women in improving dietary intake.

[High prevalence of inadequate calcium and vitamin D dietary intake in two cohorts of pregnant women]

This study aimed to identify the prevalence of inadequate calcium and vitamin D dietary intake and related factors in two cohorts of pregnant women according to trimester of pregnancy. Two 24-hour dietary recall tests were taken in each trimester, one pertaining to weekends. Variables significantly correlated with intake of these nutrients were included in a multivariate linear regression model, adjusted for energy. Prevalence of inadequate intake was estimated according to the National Cancer Institute method (United States). In cohort A, inadequate vitamin D did not differ between trimesters; in B there was a reduction: from 99.7% in the first trimester to 97.1% in the third. In cohorts A and B, inadequate calcium intake exceeded 70%, falling slightly from the first (89.2% and 81.4%) to the second (79.7% and 69.1%) and third trimesters (82.7% and 72.6%). There was no correlation between maternal variables and the intake of these micronutrients. In conclusion, intake of vitamin D and calcium is seriously inadequate and distributed homogeneously among pregnant women in the primary healthcare network.

Neonatal vitamin D status is not associated with later risk of type 1 diabetes: results from two large Danish population-based studies

AIMS/HYPOTHESIS

The aim of this work was to assess whether neonatal levels of 25-hydroxyvitamin D (25(OH)D) are associated with risk of developing type 1 diabetes before the age of 18 years.

METHODS

Two large-scale studies with different designs-a case-cohort and a case-control-were conducted using Danish national register data and biobank material. Weighted Cox regression and conditional logistic regression were used to calculate HRs and ORs, respectively. The concentration of 25(OH)D was assessed from neonatal dried blood spots using highly sensitive liquid chromatography-tandem mass spectrometry. Quintiles of 25(OH)D3 were used in the main analyses.

RESULTS

The case-cohort study included 912 type 1 diabetes cases and 2866 individuals without type 1 diabetes born in Denmark between 1981 and 2002 and followed up until the end of 2012. The case-control study included 527 matched case-control pairs born between 1981 and 1999 and followed up until May 2004. Both studies found no association between 25(OH)D3 levels and later risk of developing type 1 diabetes. The neonatal total 25(OH)D levels in the studies were low: 46% (case-cohort study) and 51% (case-control study) of individuals had 25(OH)D levels <25 nmol/l.

CONCLUSIONS/INTERPRETATION

Our two large-scale national studies showed that 25(OH)D3 levels around the time of birth were not associated with later type 1 diabetes risk. Whether higher levels of 25(OH)D3 during pregnancy, acquired by higher doses of supplementation than are recommended today in most countries, could protect the offspring against type 1 diabetes cannot be ruled out by the present studies.

Maternal micronutrient consumption periconceptionally and during pregnancy: a prospective cohort study

OBJECTIVE

To examine overall micronutrient intake periconceptionally and throughout pregnancy in a population-based cohort of Australian women.

DESIGN

In a prospective cohort study, micronutrient dosages were extracted from self-reported maternal supplement use, recorded pre-conception, and for each trimester of pregnancy. A food frequency scale (DQESv2) captured usual maternal diet for gestational weeks 14-26. The influence of sociodemographic and lifestyle factors associated with supplement use was examined using logistic regression, and changes in micronutrient intakes prior to and throughout pregnancy were assessed using repeated-measures ANOVA analyses.

SETTING

Metropolitan hospital sites in Melbourne, Australia.

SUBJECTS

Women with a viable singleton pregnancy were recruited at less than 19 weeks' gestation (n 2146).

RESULTS

Compared with non-users, women using supplements during pregnancy were more likely to have planned their pregnancy, be >25 years old, primiparous, Caucasian, non-smokers, have a tertiary education and be consuming a folate-rich diet. Intakes of folate, Fe and Zn were significantly lower in the periconceptional period, compared with other periods (P<0·001). Intakes below Recommended Daily Intake levels were common both periconceptionally and throughout pregnancy, with 19-46 % of women not meeting the Recommended Daily Intake for folate, 68-82 % for Fe and 17-36 % for Zn. Conversely, 15-19 % of women consumed beyond the recommended Upper Limit for folate and 11-24 % for Fe.

CONCLUSIONS

The study highlights the need for improved public health education on nutritional needs during pregnancy, especially among women with lower educational achievements and income.