Effects of vitamin B12 and folate deficiency on brain development in children

Importance of gene variants and co-factors of folate metabolic pathway in the etiology of idiopathic intellectual disability

Different components of the folate metabolic cycle are crucial for maintaining integrity of DNA. The present study was aimed at exploring the role of some important constituents of the folate cycle in the etiology of idiopathic intellectual disability (IID). Nuclear families with IID probands (n=226) and ethnically matched controls (n=181) were recruited for micronucleus, karyotype, genetic polymorphism (MTR rs1805087, MTRR rs1801394, and DHFR rs70991108), folate, vitamin B6, vitamin B12, and cysteine analysis. Significant difference in genotype frequencies in IID probands and their parents were observed for rs1805087 (P=0.03, 0.02), rs1801394 (P=0.03, 0.001), and rs70991108 ((P=0.03, 0.02) as compared to controls. IID probands showed significantly higher micronucleus frequency (P=0.01) and decreased vitamin B6 level (P=0.002). A strong correlation between rs1801394 'G' allele and micronucleus was also noticed. From the present investigation, a role of genetic polymorphisms and vitamin B6 levels could be hypothesized in the etiology of IID.

Vitamin B-12, folate, iron, and vitamin A concentrations in rural Indian children are associated with continued breastfeeding, complementary diet, and maternal nutrition

BACKGROUND

Determinants of vitamin B-12, folate, iron, and vitamin A concentrations in young children in rural south Asia are poorly understood. These micronutrients are crucial for the production of hemoglobin and have other important physiologic functions.

OBJECTIVE

We sought to develop explanatory models for concentrations of vitamin B-12, folate, ferritin, and retinol binding protein (RBP) in children aged between 1 and 2 y in rural Karnataka, India.

DESIGN

We performed a cross-sectional study in 12-23-mo-old toddlers who lived in 2 rural districts of Karnataka, India. For each child, data concerning dietary, food-security, and sociodemographic and maternal factors were obtained, and serum vitamin B-12, folate, ferritin, and RBP were measured. Multiple regression and structural equation modeling were applied to determine associations with micronutrient concentrations.

RESULTS

Of 396 sampled children, 254 children (65.6%) had at least one micronutrient deficiency. With the use of multiple regression, continued breastfeeding was independently associated with the concentration of each micronutrient [(log) vitamin B-12: standardized coefficient of -0.30 (P < 0.001); folate: standardized coefficient of +0.20 (P < 0.001); (log) ferritin: standardized coefficient of -0.18 (P = 0.004); (log) RBP: standardized coefficient of-0.21 (P < 0.001)]. Children who continued to breastfeed received less nutrition from complementary foods and belonged to poorer families with higher food insecurity. A structural equation model for children's vitamin B-12 concentrations was developed that highlighted the interrelation between wealth, continued breastfeeding, complementary diet, and vitamin B-12 concentrations in children.

CONCLUSIONS

Micronutrient deficiencies are common in this population. Rural Indian children between 1 and 2 y of age who continue to breastfeed should be especially targeted during micronutrient-supplementation programs. This trial was registered in the Australian and New Zealand Clinical Trials Registry as ACTRN12611000596909.

Prenatal exposure to hyperemesis gravidarum linked to increased risk of psychological and behavioral disorders in adulthood

Hyperemesis gravidarum (HG), severe nausea and vomiting of pregnancy, is characterized by long-term maternal stress, undernutrition and dehydration. While maternal stress and malnutrition of pregnancy are linked to poor neonatal outcome and associated with poor adult health, long-term outcome of fetal exposure to HG has never been explored. The purpose of this study is to determine whether long-term emotional and behavioral diagnoses may be associated with fetal exposure to HG. Emotional and behavioral diagnoses of adults born of a pregnancy complicated by HG were compared to diagnoses from non-exposed controls. Offspring exposed to HG in utero were significantly more likely to have a psychological and behavioral disorder (OR = 3.6, P < 0.0001) with diagnoses primarily of depression, bipolar disorder and anxiety. In utero exposure to HG may lead to increased risks of psychological and behavioral disorders in the offspring.

B12 in fetal development

Vitamin B12 (cobalamin) is necessary for development of the fetus and child. Pregnant women who are vegetarian or vegan, have Crohn's or celiac disease, or have undergone gastric bypass surgery are at increased risk of B12 deficiency. Low serum levels of B12 have been linked to negative impacts in cognitive, motor, and growth outcomes. Low cobalamin levels also may be related to depression in adults. Some studies indicate that B12 supplementation may improve outcomes in children, although more research is needed in this area. Overall, the mechanisms of B12 action in development remain unclear. Further studies in this area to elucidate the pathways of cobalamin influence on development, as well as to prevent B12 deficiency in pregnant women and children are indicated.

Folic acid for fragile X syndrome

BACKGROUND

It has been argued that individuals with fragile X syndrome could have low folate levels in their bodies and that supplementing their dietary intake might remediate the adverse developmental and behavioural effects of the condition.

OBJECTIVES

To review the efficacy and safety of folic acid in the treatment of people with fragile X syndrome.

SEARCH STRATEGY

We searched four databases in November 2010: CENTRAL, PubMed, EMBASE and PsycINFO.

SELECTION CRITERIA

Randomised controlled trials.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias using the Cochrane 'Risk of bias' tool.

MAIN RESULTS

We included five trials, which were published between 1986 and 1992. Overall, they included 67 patients, all male, with ages ranging from one to 54 years. Intellectual disability in participants varied from borderline to severe and some studies included patients with an additional diagnosis of autism or autistic behaviour. Four of the studies were placebo-controlled cross-over trials and one study was a parallel design. The duration of follow-up ranged from two months to 12 months and the period on folic acid or placebo ranged from two to eight months. Doses of folic acid ranged from 10 mg to 250 mg per day, 10 mg per day being the most common. Most of the younger patients involved were also taking part in special education programmes (usually involving language and occupational therapy).We were not able to perform meta-analysis to combine results but none of the individual studies found evidence of clinical benefit with the use of folic acid medication in fragile X syndrome patients on any of the areas of interest, either psychological and learning capabilities or behaviour and social performance, as measured with standardised tools. Separate analysis of evidence for patients of different age groups, i.e. prepubertal children and postpubertal young people, found some statistically significant results, but did not show clear evidence of benefit for either group. Adverse effects of folic acid treatment were rare, not serious and transient.Studies were generally poorly reported and we classified only one study as being at low risk of bias.

AUTHORS' CONCLUSIONS

The quality of available evidence is low and not suitable for drawing conclusions about the effect of folic acid on fragile X syndrome patients. It consists of few studies with small samples of patients, all of them male, with little statistical power to detect anything other than huge effects.

Maternal vitamin B-12 and folate status during pregnancy and excessive infant crying

BACKGROUND

The etiology of excessive infant crying is largely unknown. We hypothesize that excessive infant crying may have an early nutritional origin during fetal development.

AIMS

This study is the first to explore whether (1) maternal vitamin B-12 and folate status during pregnancy are associated with excessive infant crying, and (2) whether and how maternal psychological well-being during pregnancy affects these associations.

STUDY DESIGN

Women were approached around the 12th pregnancy week to complete a questionnaire (n=8266) and to donate a blood sample (n=4389); vitamin B-12 and folate concentrations were determined in serum. Infant crying behavior was measured through a postpartum questionnaire (±3 months; n=5218).

SUBJECTS

Pregnant women living in Amsterdam and their newborn child.

OUTCOME MEASURES

Excessive infant crying, defined as crying ≥3 h/day on average in the past week.

RESULTS

Multiple logistic regression analysis was performed for 2921 (vitamin B-12) and 2622 (folate) women.Vitamin B-12 concentration (categorized into quintiles) was associated with excessive infant crying after adjustment for maternal age, parity, ethnicity, education, maternal smoking and psychological problems (OR[95%CI]: Q1=3.31[1.48-7.41]; Q2=2.50[1.08-5.77]; Q3=2.59[1.12-6.00]; Q4=2.77[1.20-6.40]; Q5=reference). Stratified analysis suggested a stronger association among women with high levels of psychological problems during pregnancy. Folate concentration was not associated with excessive infant crying.

CONCLUSIONS

First evidence is provided for an early nutritional origin in excessive infant crying. A low maternal vitamin B-12 status during pregnancy could, in theory, affect infant crying behavior through two potential mechanisms: the methionine-homocysteine metabolism and/or the maturation of the sleep-wake rhythm.

Lifestyle, nutrient intake, iron status, and pregnancy outcome in pregnant women of advanced maternal age

The purpose of this study was to investigate how advanced maternal age influences lifestyle, nutrient intake, iron status, and pregnancy outcomes in pregnant women. The subjects of this study were 112 pregnant women who were receiving prenatal care at gynecologists located in Seoul. The subjects were divided into two groups according to their ages: those over age 35 were the advanced age group of pregnant women (AP) and those under age 35 were the young age group of pregnant women (YP). General factors, nutrient intakes, iron status, and pregnancy outcomes of the two groups were then compared. It was found that 72.5% of the YP group and 51.2% of the AP group had pre-pregnancy alcohol drinking experience; indicating that the YP group had more pre-pregnancy alcohol consumption than the AP group (P < 0.05). The only difference found in nutrient intake between the two groups was their niacin intakes which were 16.83 ± 8.20 mg/day and 13.76 ± 5.28 mg/day, respectively. When gestational age was shorter than 38.7 weeks, the average infant birth weight was 2.95 ± 0.08 kg, and when gestational age was longer than 40 weeks, it averaged at about 3.42 ± 0.08 kg. In other words, as gestational age increased, infant birth weight increased (P < 0.0001), and when maternal weight increased more than 15 kg, the infant birth weight increased significantly (P < 0.05). In conclusion, in order to secure healthy human resources, with respect to advanced aged women, it is necessary to intervene by promoting daily habits that consist of strategic increases in folate and calcium intake along with appropriate amounts of exercise.

Cobalamin status in children

Cobalamin and the metabolic markers methylmalonic acid and total homocysteine undergo marked changes during childhood. In breastfed infants a metabolic profile indicative of cobalamin deficiency is common. Symptoms of cobalamin deficiency in children differ with age, presenting a continuum from subtle developmental delay to life-threatening clinical conditions. The symptoms may be difficult to detect, particularly in infants, and there tends to be a diagnostic delay of several months in this age group. Several reports show that even moderate deficiency in children may be harmful, and long-term consequences of neurological deterioration may persist after cobalamin deficiency has been treated. Given the crucial role of cobalamin for normal growth and development, possible widespread infantile deficiency needs attention. Cobalamin deficiency should be considered a differential diagnosis in children with subtle symptoms, and strategies to prevent cobalamin deficiency in mothers and children should be addressed.

Animal products, diseases and drugs: a plea for better integration between agricultural sciences, human nutrition and human pharmacology

Eicosanoids are major players in the pathogenesis of several common diseases, with either overproduction or imbalance (e.g. between thromboxanes and prostacyclins) often leading to worsening of disease symptoms. Both the total rate of eicosanoid production and the balance between eicosanoids with opposite effects are strongly dependent on dietary factors, such as the daily intakes of various eicosanoid precursor fatty acids, and also on the intakes of several antioxidant nutrients including selenium and sulphur amino acids. Even though the underlying biochemical mechanisms have been thoroughly studied for more than 30 years, neither the agricultural sector nor medical practitioners have shown much interest in making practical use of the abundant high-quality research data now available. In this article, we discuss some specific examples of the interactions between diet and drugs in the pathogenesis and therapy of various common diseases. We also discuss, using common pain conditions and cancer as specific examples, how a better integration between agricultural science, nutrition and pharmacology could lead to improved treatment for important diseases (with improved overall therapeutic effect at the same time as negative side effects and therapy costs can be strongly reduced). It is shown how an unnaturally high omega-6/omega-3 fatty acid concentration ratio in meat, offal and eggs (because the omega-6/omega-3 ratio of the animal diet is unnaturally high) directly leads to exacerbation of pain conditions, cardiovascular disease and probably most cancers. It should be technologically easy and fairly inexpensive to produce poultry and pork meat with much more long-chain omega-3 fatty acids and less arachidonic acid than now, at the same time as they could also have a similar selenium concentration as is common in marine fish. The health economic benefits of such products for society as a whole must be expected vastly to outweigh the direct costs for the farming sector.

Perinatal folate supply: relevance in health outcome parameters

The importance of physiological supply of folate is well recognized in human health; the crucial roles of folate in one-carbon metabolism for physiological DNA synthesis and cell division, as well as in the conversion of homocysteine (Hcy) to methionine, and subsequently, to S-adenosylmethionine, have been convincingly demonstrated. Improved folate status may reduce the risk of macrocytic anaemia, cardiovascular diseases, neuropsychiatric disorders and adverse pregnancy outcomes. Inadequate folate status results in a decrease in the methylation cycle and in increased blood levels of the neurotoxic Hcy. The aim of this review is to provide insight into the influence of folate status on pregnancy health outcomes, and to consider increasing evidence of a link between the extent of genome/epigenome damage and elevated risk for adverse obstetrical endpoints. Pregnant women are at risk for folate insufficiency because of the increased need for folate for rapid fetal growth, placental development and enlargement of the uterus. Inadequate folate status may cause fetal malformations, impaired fetal growth, pre-term delivery and maternal anaemia. Even some diseases of the placenta may arise from folate deficiencies. Fetal growth seems to be vulnerable to maternal folate status during the periconception period, because it has the potential to affect both the closure of the neural tube and several epigenetic mechanisms within the placenta and the fetus. Mainly on the basis of the well recognized link between maternal folate status and fetal neural tube defects, women are advised to receive folic acid supplement during the periconceptional period. Because an adequate folate supply seems to play an important role in the implantation and development of the placenta and in improving endothelial function, folic acid supplementation in the late first trimester or early second trimester might also be beneficial.

Role of maternal vitamin B12 on the metabolic health of the offspring: a contributor to the diabetes epidemic?

There is increasing evidence, in humans and other mammals, that periconceptional nutritional status influences health in adulthood. This is called ‘foetal programming’ and is likely to be mediated through DNA methylation. Micronutrients, especially B vitamins such as folic acid and vitamin B12 play crucial roles in providing methyl groups for such reactions. This is called epigenetic regulation and may provide some clues to the epidemic of type 2 diabetes and cardiovascular disease. Evidence from mandatory folic acid fortification studies suggests that in the presence of adequate folic acid, neural tube defects due to B12 deficiency have tripled. Such ‘imbalance of high folic acid and low vitamin B12’ in the elderly causes cognitive impairment. A longitudinal study of young women in India showed that children born to those with ‘high folic acid and low B12’ had higher adiposity and insulin resistance. In addition to increased levels of folic acid, B12 deficiency is increasing in countries with mandatory folic acid fortification. Studies on the prevalence of vitamin B12 deficiency during pregnancy and in women of childbearing age, plus the effects of B12 supplementation are therefore urgently needed. This article reviews the role of vitamin B12 during pregnancy on the offspring’s metabolic risk.

Higher maternal plasma folate but not vitamin B-12 concentrations during pregnancy are associated with better cognitive function scores in 9- to 10- year-old children in South India

Folate and vitamin B-12 are essential for normal brain development. Few studies have examined the relationship of maternal folate and vitamin B-12 status during pregnancy and offspring cognitive function. To test the hypothesis that lower maternal plasma folate and vitamin B-12 concentrations and higher plasma homocysteine concentrations during pregnancy are associated with poorer neurodevelopment, 536 children (aged 9-10 y) from the Mysore Parthenon birth cohort underwent cognitive function assessment during 2007-2008 using 3 core tests from the Kaufman Assessment Battery, and additional tests measuring learning, long-term storage/retrieval, attention and concentration, and visuo-spatial and verbal abilities. Maternal folate, vitamin B-12, and homocysteine concentrations were measured at 30 +/- 2 wk gestation. During pregnancy, 4% of mothers had low folate concentrations (<7 nmol/L), 42.5% had low vitamin B-12 concentrations (<150 pmol/L), and 3% had hyperhomocysteinemia (>10 micromol/L). The children's cognitive test scores increased by 0.1-0.2 SD per SD increase across the entire range of maternal folate concentrations (P < 0.001 for all), with no apparent associations at the deficiency level. The associations with learning, long-term storage/retrieval, visuo-spatial ability, attention, and concentration were independent of the parents' education, socioeconomic status, religion, and the child's sex, age, current size, and folate and vitamin B-12 concentrations. There were no consistent associations of maternal vitamin B-12 and homocysteine concentrations with childhood cognitive performance. In this Indian population, higher maternal folate, but not vitamin B-12, concentrations during pregnancy predicted better childhood cognitive ability. It also suggests that, in terms of neurodevelopment, the concentration used to define folate deficiency may be set too low.

Micronutrients and women of reproductive potential: required dietary intake and consequences of dietary deficiency or excess. Part I--Folate, Vitamin B12, Vitamin B6

This two-part review highlights micronutrients for which either public health policy has been established or for which new evidence provides guidance as to recommended intakes during pregnancy. One pivotal micronutrient is folate, the generic name for different forms of a water-soluble vitamin essential for the synthesis of thymidylate and purines and, hence, DNA. For non-pregnant adult women the recommended intake is 400 μg/day dietary folate equivalent. For women capable of becoming pregnant an additional 400 μg/day of synthetic folic acid from supplements or fortified foods is recommended to reduce the risk of neural tube defects (NTD). The average amount of folic acid received through food fortification (grains) in the US is only 128 μg/day, emphasising the need for the supplemental vitamin for women of reproductive age. Vitamin B12 (cobalamin) is a cofactor required for enzyme reactions, including generation of methionine and tetrahydrofolate. B12 is found almost exclusively in foods of animal origin (meats, dairy products); therefore, vegetarians are at greatest risk for dietary vitamin B12 deficiency and should be supplemented. Vitamin B6 is required for many reactions, primarily in amino acid metabolism. Meat, fish and poultry are good dietary sources. Supplementation beyond routine prenatal vitamins is not recommended.