Relationship between body-mass index and serum folate concentrations in pregnant women

Methylenetetrahydrofolate Reductase C677T Gene Variant in Relation to Body Mass Index and Folate Concentration in a Polish Population

BACKGROUND

Methylenetetrahydrofolate reductase (MTHFR) is an enzyme responsible for producing an active form of folate. The MTHFR T677T genotype may have adverse health effects associated with weight gain and a reduction in folate availability.

AIM

In this study, we examined the influence of the MTHFR C677T variant on BMI and determined its role as a risk factor for obesity. We also assessed the relationships between the MTHFR C677T genotype and folate and vitamin B₁₂ concentrations in subjects before and after radical weight loss.

METHODS

The study group consisted of 1712 Caucasian adults of Polish nationality with a wide range of body mass indexes (BMIs). DNA was extracted from the blood, and the C677T variant was tested with RFLP-PCR and real-time-PCR.

RESULTS

There was no significant influence found for the MTHFR 677 TT genotype on BMI or the obesity risk in codominant, dominant or recessive inheritance models. Individuals with obesity and the TT genotype had significantly lower folate concentrations. After radical weight reduction, the impact of the risk genotype, as well as homeostasis between folate and vitamin B₁₂ in TT homozygotes, seems to be attenuated.

CONCLUSION

Although the MTHFR 677TT genotype is not directly related to a higher BMI in Polish adults, it has a detrimental effect on folate concentrations in individuals with high BMI values.

Nutritional management of individuals with obesity and COVID-19: ESPEN expert statements and practical guidance

The COVID-19 pandemics has created unprecedented challenges and threats to patients and healthcare systems worldwide. Acute respiratory complications that require intensive care unit (ICU) management are a major cause of morbidity and mortality in COVID-19 patients. Among other important risk factors for severe COVID-19 outcomes, obesity has emerged along with undernutrition-malnutrition as a strong predictor of disease risk and severity. Obesity-related excessive body fat may lead to respiratory, metabolic and immune derangements potentially favoring the onset of COVID-19 complications. In addition, patients with obesity may be at risk for loss of skeletal muscle mass, reflecting a state of hidden malnutrition with a strong negative health impact in all clinical settings. Also importantly, obesity is commonly associated with micronutrient deficiencies that directly influence immune function and infection risk. Finally, the pandemic-related lockdown, deleterious lifestyle changes and other numerous psychosocial consequences may worsen eating behaviors, sedentarity, body weight regulation, ultimately leading to further increments of obesity-associated metabolic complications with loss of skeletal muscle mass and higher non-communicable disease risk. Therefore, prevention, diagnosis and treatment of malnutrition and micronutrient deficiencies should be routinely included in the management of COVID-19 patients in the presence of obesity; lockdown-induced health risks should also be specifically monitored and prevented in this population. In the current document, the European Society for Clinical Nutrition and Metabolism (ESPEN) aims at providing clinical practice guidance for nutritional management of COVID-19 patients with obesity in various clinical settings.

Maternal obesity during pregnancy leads to derangements in one-carbon metabolism and the gut microbiota: implications for fetal development and offspring wellbeing

A healthy diet before and during pregnancy is beneficial in acquiring essential B vitamins involved in 1-carbon metabolism, and in maintaining a healthy gut microbiota. Each play important roles in fetal development, immune-system remodeling, and pregnancy-nutrient acquisition. Evidence shows that there is a reciprocal interaction between the one-carbon metabolism and the gut microbiota given that dietary intake of B vitamins has been shown to influence the composition of the gut microbiota, and certain gut bacteria also synthesize B vitamins. This reciprocal interaction contributes to the individual's overall availability of B vitamins and, therefore, should be maintained in a healthy state during pregnancy. There is an emerging consensus that obese pregnant women often have derangements in 1-carbon metabolism and gut dysbiosis owing to high intake of nutritiously poor foods and a chronic systemic inflammatory state. For example, low folate and vitamin B₁₂ in obese women coincide with the decreased presence of B vitamin-producing bacteria and increased presence of inflammatory-associated bacteria from approximately mid-pregnancy. These alterations are risk factors for adverse pregnancy outcomes, impaired fetal development, and disruption of fetal growth and microbiota formation, which may lead to potential long-term offspring metabolic and neurologic disorders. Therefore, preconceptional and pregnant obese women may benefit from dietary and lifestyle counseling to improve their dietary nutrient intake, and from monitoring their B vitamin levels and gut microbiome by blood tests and microbiota stool samples. In addition, there is evidence that some probiotic bacteria have folate biosynthetic capacity and could be used to treat gut dysbiosis. Thus, their use as an intervention strategy for obese women holds potential and should be further investigated. Currently, there are many knowledge gaps concerning the relationship between one-carbon metabolism and the gut microbiota, and future research should focus on intervention strategies to counteract B vitamin deficiencies and gut dysbiosis in obese pregnant women, commencing with the use of probiotic and prebiotic supplements.

Serum folate concentration and health-related quality of life among the elderly in South Korea

Background

The purpose of this study was to investigate the association between serum folate concentration and health-related quality of life (HRQOL) among the elderly in South Korea.

Materials and methods

The data used in this study were drawn from 1,021 participants over 65 years old in the Korea National Health and Nutrition Examination Survey from 2016–2018. HRQOL was measured by the EQ-5D questionnaire. Participants were divided into tertiles of folate concentration (ranges 1.7–5.6, 5.7–9.4, and 9.5–31.9 ng/mL). We performed multivariable linear regression to examine the relationship between folate and HRQOL, and multivariable logistic regression to examine the relationship between folate and the dimensional problem of HRQOL.

Results

Higher folate concentrations were significantly associated with higher HRQOL in the elderly. The average HRQOL score of the elderly in the highest tertile of the folate level was 0.0289 higher than that of the lowest tertile (coefficient: 0.0289; 95% CI 0.0016, 0.0563). The HRQOL score increased by 0.0174 points when the folate concentration increased by 100%. When analyzing specific dimensions, a significant association with folate concentration was found only for the self-care dimension of HRQOL (odds ratio for self-care problems: 0.63; 95% CI 0.41, 0.99).

Conclusions

The elderly with higher serum folate concentration tended to have higher HRQOL. Among HRQOL dimensions, self-care was only significantly associated with folate concentration.

The Potential Role of Vitamin B12 in the Prevention of COVID-19 Complications: A Narrative Review

The elderly are more prone to mortality from COVID-19 infection, as they are susceptible to develop acute respiratory distress syndrome (ARDS). For COVID-19 patients with ARDS caused by sepsis or septic shock, high-dose parenteral vitamin B12 appears to be a potential new treatment option. Vitamin B12 may play a substantial impact in COVID-19 morbidity and mortality reduction owing to its function in DNA synthesis, cellular control, improvement of anti-inflammatory immune responses, and decrease of pro-inflammatory responses. This review aims to assess the functional role of Vitamin B12 in COVID-19 in terms of its immunomodulatory effect, role in cellular and humoral immunity and maintaining the gut microbe homeostasis. From data inception to June 2021, accessible electronic databases were searched for research/review articles reporting on the function of Vitamin B12 in COVID-19. Scopus, Web of Science, PubMed, WHO worldwide research on COVID-19 and the clinical trials registration “https://clinicaltrials.gov/” were used to conduct the systematic search by using keywords: “COVID-19 and “Vitamin B12”. Also, based on these outcomes, it can be concluded that Vitamin B12 may have a potential role in preventing COVID-19 complications. Further, studies evaluating the role of Vitamin B12 in COVID-19 may open a new array of ideas on the optimal and the well-tolerated dose and timing of its administration in COVID-19 patients.

Trends and influencing factors of plasma folate levels in Chinese women at mid-pregnancy, late pregnancy and lactation periods

Folate status for women during early pregnancy has been investigated, but data for women during mid-pregnancy, late pregnancy or lactation are sparse or lacking. Between May and July 2014, we conducted a cross-sectional study in 1211 pregnant and lactating women from three representative regions in China. Approximately 135 women were enrolled in each stratum by physiological periods (mid-pregnancy, late pregnancy or lactation) and regions (south, central or north). Plasma folate concentrations were measured by microbiological assay. The adjusted medians of folate concentration decreased from 28·8 (interquartile range (IQR) 19·9, 38·2) nmol/l in mid-pregnancy to 18·6 (IQR 13·2, 26·4) nmol/l in late pregnancy, and to 17·0 (IQR 12·3, 22·5) nmol/l in lactation (Pfor trend < 0·001). Overall, lower folate concentrations were more likely to be observed in women residing in the northern region, with younger age, higher pre-pregnancy BMI, lower education or multiparity, and in lactating women who had undergone a Caesarean delivery or who were breastfeeding exclusively. In total, 380 (31·4 %) women had a suboptimal folate status (folate concentration <13·5 nmol/l). Women in late pregnancy and lactating, residing in the northern region, having multiparity and low education level had a higher risk of suboptimal folate status, while those with older age had a lower risk. In conclusion, maternal plasma folate concentrations decreased as pregnancy progressed, and were influenced by geographic region and maternal socio-demographic characteristics. Future studies are warranted to assess the necessity of folic acid supplementation during later pregnancy and lactation especially for women at a higher risk of folate depletion.

The effect of prepregnancy body mass index on maternal micronutrient status: a meta-analysis

The relationship between prepregnancy body mass index (BMI) and maternal micronutrient status is inconsistent and has not received sufficient attention. This meta-analysis aimed to evaluate the effect of prepregnancy BMI on micronutrient levels in pregnant women. PubMed, Embase, Web of Science, and the Cochrane Library were searched for articles that contained information on micronutrient levels and prepregnancy BMI. A random-effects model was used to determine the association between prepregnancy BMI and maternal micronutrient status. Sixty-one eligible articles were eventually included, with 83,554 participants. Vitamin B12, folate, vitamin D, iron and ferritin were the main micronutrients evaluated in our meta-analysis. Prepregnancy obesity and overweight may lead to an increased risk of micronutrient deficiency, including vitamin B12, folate and vitamin D deficiency, while prepregnancy obesity or overweight may have no significant association with ferritin deficiency. Additionally, the results of the dose-response analyses demonstrated a possible significant inverse correlation between prepregnancy BMI and levels of micronutrient, except for iron and ferritin. Compared with women with normal weight, women who were overweight or obese prepregnancy have lower micronutrient concentrations and are more likely to exhibit micronutrient deficiency during pregnancy, which is harmful to both mothers and neonates.

COVID-19's toll on the elderly and those with diabetes mellitus - Is vitamin B12 deficiency an accomplice?

COVID-19 exacts a disproportionate toll on both the elderly and those with diabetes; these patients are more likely to require costly intensive care, longer hospitalisation, and die from complications. Nations would thus find it extremely difficult to either lift or sustain socially, economically, and politically damaging restrictions that keep this group of people safe. Without a vaccine, there is thus an urgent need to identify potential modifiable risk factors which can help manage overall fatality or recovery rates. Case fatality rates are highly variable between (and even within) nations; nutritional differences have been proposed to account significantly for this disparity. Indeed, vitamin B12 deficiency is a common denominator between the elderly and those with diabetes. The question on hand thus lies on whether managing B12 deficiencies will impact COVID-19 fatality outcome or recovery rates. Herein, we review the latest evidence that shows that B12 deficiency associates in multiple areas very similar to where COVID-19 exerts its damaging effects: immunologically; microbiologically; haematologically; and through endothelial cell signalling-supporting the hypothesis that B12 deficiency is a potential modifiable risk factor in our fight against COVID-19.

The influence of obesity on folate status, DNA methylation and cancer-related gene expression in normal breast tissues from premenopausal women

Epidemiological studies have established obesity as a critical risk factor for postmenopausal breast cancer (post-BC), whereas a reverse association holds prior to menopause. A significant scientific gap exists in understanding the mechanism(s) underpinning this epidemiological phenomenon, particularly the reverse association between obesity and premenopausal breast cancer (pre-BC). This study aimed to understand how folate metabolism and DNA methylation inform the association between obesity and pre-BC. Fifty normal breast tissue samples were collected from premenopausal women who underwent reduction mammoplasty. We modified the Lactobacillus Casei microbiological folate assay and measured folate levels in our breast tissue samples. The DNA methylation of LINE-1, a biomarker of genome-wide methylation, and the expression of a panel of breast cancer-related genes was measured by pyrosequencing and real-time PCR. We found that a high BMI is associated with an increase of folate levels in mammary tissue, with an increase of 2.65 ng/g of folate per every 5-unit increase of BMI (p < 0.05). LINE-1 DNA methylation was significantly associated with BMI (p < 0.05), and marginally associated with folate concentration (p = 0.087). A high expression of SFRP1 was observed in subjects with high BMI or high folate status (p < 0.05). This study demonstrated that, in premenopausal women, obesity is associated with increased mammary folate status, genome-wide DNA methylation and SFRP1 gene expression. Our findings indicated that the improved folate and epigenetic status represents a novel mechanism responsible for the reverse association between obesity and pre-BC.

Low folate intake and serum levels are associated with higher body mass index and abdominal fat accumulation: a case control study

BACKGROUND

The link between folate metabolism and obesity has recently been underlined, suggesting that folate deficiency may lead to body weight gain and adiposity. We thus wished to determine whether the inefficiency in folate metabolism caused by genetic variation in the MTHFR and DHFR genes in folate metabolism, or inadequate folate intake, is associated with obesity.

METHODS

A case-control study including 421 healthy participants (aged 20-40) was performed in Poznań, Poland. The cases were 213 subjects with BMI > 25 kg/m2, while the controls were 208 subjects with BMI < 25 kg/m2. Genotyping of rs70991108 (DHFR) and rs1801133 (MTHFR) was performed using TaqMan probes. Serum folate concentrations were measured using an enzyme-linked immunosorbent assay and homocysteine was assessed with high performance liquid chromatography.

RESULTS

Subjects with overweight and obesity had 12% lower folate intake (p < 0.05) and 8.5% lower folate serum concentrations (p < 0.01) than the controls. Serum folate concentrations and folate intake were inversely associated with body fat percentage (p < 0.05) and waist circumference (p < 0.05 and p < 0.001, respectively). Serum folate concentration, though not folate intake, was negatively associated with WHR and BMI (p < 0.05, for both associations).

CONCLUSIONS

Lower folate intake and serum levels are weakly, but independently, associated with greater body weight and central adiposity in people aged 20-40. MTHFR and DHFR polymorphism seems not to have significant impact on body weight.

Environmental pollutants affecting children's growth and development: Collective results from the MOCEH study, a multi-centric prospective birth cohort in Korea

BACKGROUND

The Mothers and Children's Environmental Health study (MOCEH) is a multi-centric prospective birth cohort study investigating effects of various environmental pollutants like heavy metals, endocrine disruptors, air pollutants, nutrition and lifestyle on birth outcomes, growth and development, health and disease of children. In this study, we report all the outcomes from the MOCEH study describing the different environmental pollutants affecting children's health and disease.

METHODS

In MOCEH study, 1,751 pregnant women in their first trimester were recruited at 3 centers from 2006 to 2010 in South Korea. The children were followed from birth up to 6 years. Information on health outcomes of children including birth parameters, demographic characteristics, medical and child-rearing history, and nutritional status, were repeatedly obtained through the follow-ups by questionnaires administration, clinical evaluation, and biological specimen collection and measurements. Prenatal and postnatal measurement in biospecimen, i.e., lead, mercury, cadmium, manganese, 1-hydroxypyrene, 2-naphthol, malonadialdehyde, hippuric acid, bisphenol A and phthalate metabolites, and measurement in air samples, i.e., particulate matter, nitrogen dioxide, and total volatile organic compounds were performed.

RESULTS

The results show the adverse effect of prenatal exposure to heavy metals like mercury, lead and cadmium on children's physical, cognitive and neurobehavioral development. Exposure to endocrine disruptors, air pollution, second hand smoke, and mother's lifestyle during pregnancy affects children's growth and development. We also identified specific window periods of exposure of pollutants significantly related to children's health outcomes.

CONCLUSION

The collective results from MOCEH study provide strong scientific evidence that exposures to prenatal and postnatal environmental pollutants have a negative effect on growth and development of children, which will be useful in implementing effective national policy to improve children's environmental health.

The Impact of Maternal Pre-Pregnancy Body Weight and Gestational Diabetes on Markers of Folate Metabolism in the Placenta

Dietary methyl donors, including folate, may modify the placenta and size at birth but the influence of maternal body weight has not been widely investigated. We therefore examined whether maternal or fetal folate status, together with indices of placental folate transport, were modulated by either maternal pre-pregnancy body mass index (BMI i.e., overweight: 25 ≤ BMI < 30 or obesity: BMI ≥ 30 kg/m²) and/or gestational diabetes mellitus (GD). We utilised a sub-sample of 135 pregnant women participating in the Spanish PREOBE survey for our analysis (i.e., 59 healthy normal weight, 29 overweight, 22 obese and 25 GD). They were blood sampled at 34 weeks gestation, and, at delivery, when a placental sample was taken together with maternal and cord blood. Placental gene expression of folate transporters and DNA methyltransferases (DNMT) were all measured. Folate plasma concentrations were determined with an electro-chemiluminescence immunoassay. Food diaries indicated that folate intake was unaffected by BMI or GD and, although all women maintained normal folate concentrations (i.e., 5–16 ng/mL), higher BMIs were associated with reduced maternal folate concentrations at delivery. Umbilical cord folate was not different, reflecting an increased concentration gradient between the mother and her fetus. Placental mRNA abundance for the folate receptor alpha (FOLR1) was reduced with obesity, whilst DNMT1 was increased with raised BMI, responses that were unaffected by GD. Multi-regression analysis to determine the best predictors for placental FOLR1 indicated that pre-gestational BMI had the greatest influence. In conclusion, the placenta’s capacity to maintain fetal folate supply was not compromised by either obesity or GD.

Perinatal high fat diet and early life methyl donor supplementation alter one carbon metabolism and DNA methylation in the brain

One carbon metabolism is regulated by the availability of nutrients known as methyl donors, and disruption of this pathway can affect multiple physiological systems. DNA methylation, critical for the regulation of gene expression, is linked to one carbon metabolism, and can be altered by perinatal diet. In this study, dams (n = 12/group) were fed HF or standard control (SC) diet through pregnancy and lactation, and male and female offspring were then fed either SC or methyl donor-supplemented diet (MDS) between 3 and 6 weeks of age (n = 20-26/group). Concentration of one carbon intermediates and other related metabolites were assessed within brain tissue (prefrontal cortex, PFC) through the use of mass spectrometry at 6 weeks of age. In addition, the expression of target genes and enzymes that participate in DNA methylation or are relevant to one carbon metabolism were measured. We found that MDS increases the concentration of folate intermediates in the PFC, and that this increase is blunted in male offspring from dams fed a HF diet. In addition, perinatal HF diet increased the concentration of cysteine in the PFC of both male and female offspring, consistent with oxidative stress. Furthermore, both maternal HF diet and postnatal MDS altered global DNA methylation in the PFC in males but not females. Collectively, these data demonstrate sex differences in changes in one carbon metabolites in the prefrontal cortex in response to early life high fat diet and methyl donor supplementation. Read the Editorial Highlight for this article on page 358.

Impact of Pre-Pregnancy BMI on B Vitamin and Inflammatory Status in Early Pregnancy: An Observational Cohort Study

Maternal nutrition and inflammation have been suggested as mediators in the development of various adverse pregnancy outcomes associated with maternal obesity. We have investigated the relation between pre-pregnancy BMI, B vitamin status, and inflammatory markers in a group of healthy pregnant women. Cobalamin, folate, pyridoxal 5′-phosphate, and riboflavin; and the metabolic markers homocysteine, methylmalonic acid, and 3-hydroxykynurenine/xanthurenic acid ratio (HK/XA); and markers of cellular inflammation, neopterin and kynurenine/tryptophan ratio (KTR) were determined in pregnancy week 18 and related to pre-pregnancy body mass index (BMI), in 2797 women from the Norwegian Mother and Child Cohort Study (MoBa). Pre-pregnancy BMI was inversely related to folate, cobalamin, pyridoxal 5′-phosphate (PLP), and riboflavin (p < 0.001), and associated with increased neopterin and KTR levels (p < 0.001). Inflammation seemed to be an independent predictor of low vitamin B6 status, as verified by low PLP and high HK/XA ratio. A high pre-pregnancy BMI is a risk factor for low B vitamin status and increased cellular inflammation. As an optimal micronutrient status is vital for normal fetal development, the observed lower B vitamin levels may contribute to adverse pregnancy outcomes associated with maternal obesity and B vitamin status should be assessed in women with high BMI before they get pregnant.

Serum and red-blood-cell folate demonstrate differential associations with BMI in pregnant women

Objective

To examine the association between BMI and folate concentrations in serum and red blood cells (RBC) in pregnant women.

Design

A cross-sectional comparison of folate concentrations in serum and RBC sampled simultaneously from the same individual.

Setting

The Ottawa Hospital and Kingston General Hospital, Ontario, Canada.

Subjects

Pregnant women recruited between 12 and 20 weeks of gestation.

Results

A total of 869 pregnant women recruited from April 2008 to April 2009 were included in the final analysis. Serum folate was inversely associated and RBC folate positively associated with BMI, after adjusting for folic acid supplementation, age, gestational age at blood sample collection, race, maternal education, annual income, smoking and MTHFR 677C→T genotype. In stratified analyses, this differential association was significant in women with the MTHFR CC variant. In women with the CT and TT variants, the differential associations were in the same direction but not significant. Folic acid supplementation during pregnancy did not alter the differential association of BMI with serum and RBC folate concentration. This indicates that the current RBC folate cut-off approach for assessing risk of neural tube defects in obese women may be limited.

Conclusions

BMI is inversely associated with serum folate and positively associated with RBC folate in pregnant women, especially for those with the MTHFR CC variant.

Folic acid supplementation, preconception body mass index, and preterm delivery: findings from the preconception cohort data in a Chinese rural population

BACKGROUND

Folic acid (FA) supplementation before and during the first trimester can reduce the risk of occurrence of preterm delivery (PTD). Preconception body mass index (BMI) is also associated with PTD. This study aimed to investigate the combined effect of FA supplements and preconception BMI on the risk of PTD.

METHODS

The data of a cohort from 2010-2011 that was obtained through a preconception care service in China was used (including 172,206 women). A multivariable regression model was used to investigate the association between maternal preconception conditions and the risk of PTD. The interaction of preconception BMI and FA supplementation was measured by a logistic regression model.

RESULTS

Taking FA supplements in the preconception period or in the first trimester reduced the risk of PTD (odds ratio [OR] = 0.58 and OR = 0.61, respectively). Women with an abnormal BMI had an increased risk of PTD (OR = 1.09, OR = 1.10, and OR = 1.17 for underweight, overweight, and obese, respectively). Preconception BMI showed an interaction with the protective effect of FA supplementation for PTD. With regard to the interaction of FA supplementation, the adjusted odds ratio (aOR) was 0.57 (95% CI: 0.51, 0.64) in underweight women, 0.85 (95% CI: 0.73, 0.98) in overweight women, and 0.77 (95% CI, 0.65, 0.91) in obese women. Preconception BMI also showed an interaction with the time of FA supplementation. Women with a normal BMI who began to take FA supplements in the preconception period had the lowest risk of PTD (aORs: 0.58 vs. 0.65 beginning in the first trimester). The aORs at preconception and the first trimester in the underweight group were 0.56 vs. 0.60. The aORs at preconception and the first trimester were 0.94 vs. 0.65 and 1.15 vs. 0.60 in the overweight and obesity groups, respectively.

CONCLUSIONS

In our study, FA supplements reduced the risk of PTD, while abnormal BMI raised the risk of PTD, although higher BMI categories did not have this higher risk once adjusted analysis was conducted. The protective effect of FA supplementation for PTD was reduced in women with overweight or obesity. To get better protection of FA supplementation, women with normal BMI or underweight should begin to use in preconception, while women with overweight or obesity should begin to use after conception.

The MTHFD1 1958G>A variant is associated with elevated C-reactive protein and body mass index in Canadian women from a premature birth cohort

MTHFD1 1958G>A, a polymorphism in folate metabolism, increases risk of pregnancy complications. A mouse model exhibited developmental defects, increased weight and decreased leukocyte counts. To examine the latter associations, we genotyped 651 women from a premature birth cohort. Prematurity and 1958G>A were not associated. Increases in the inflammatory marker CRP (logistic regression, p = 0.055) and BMI (chi-square, p = 0.0113) were associated with AA genotype in women with low folate. MTHFD1 1958G>A may influence immune function and obesity.

Maternal predictors of intrauterine growth restriction

PURPOSE OF REVIEW

Intrauterine growth restriction (IUGR) occurs when fetal growth rate falls below the genetic potential and affects a significant number of pregnancies, but still no therapy has been developed for this pregnancy disease. This article reviews the most recent findings concerning maternal characteristics and behaviours predisposing to IUGR as well as maternal early markers of the disease. A comprehensive understanding of factors associated with IUGR will help in providing important tools for preventing and understanding adverse outcomes.

RECENT FINDINGS

Maternal nutritional status, diet and exposure to environmental factors are increasingly acknowledged as potential factors affecting fetal growth both by altering nutrient availability to the fetus and by modulating placental gene expression, thus modifying placental function.

SUMMARY

Assessing nutritional and environmental factors associated with IUGR, and the molecular mechanisms by which they may have a role in the disease onset, is necessary to provide comprehensive and common guidelines for maternal care and recommended behaviours. Moreover, maternal genetic predispositions and early serum markers may allow a better and more specific monitoring of high risk pregnancies, optimizing the timing of delivery.

Obesity affects short-term folate pharmacokinetics in women of childbearing age

Maternal folate status and body mass index (BMI) are independent risk factors for neural tube defects (NTD). Population-based studies have identified an inverse association between serum folate and BMI, after adjusting for intake. The objective of this intervention study was to compare the relationship between BMI and the short-term pharmacokinetic response to an oral dose of folic acid. Healthy obese (BMI 30.0 kg m(-2); n=16) and normal-weight (BMI 18.5-24.9 kg m(-2); n=16) women of childbearing age (18-35 years) were administered a single oral dose of folic acid (400 μg). Blood samples were collected over a 10-h period to evaluate the serum folate response. Fasting baseline serum folate was lower in the obese group (P=0.005); in contrast, red blood cell folate was higher (P=0.05). Area-under-the-curve for the absorption phase (0-3 h) and peak serum folate concentrations were lower in obese versus normal-weight women (P<0.005). Overall serum folate response (0-10 h) was lower in obese versus normal-weight women (repeated-measures ANOVA, P=0.001). Data suggest body distribution of folate is significantly affected by obesity, and, should pregnancy occur, may reduce the amount of folate available to the developing embryo. These findings provide additional support for a BMI-adjusted folic acid intake recommendation for NTD risk reduction.