Undernutrition, fatty acid and micronutrient status in relation to cognitive performance in Indian school children: a cross-sectional study

Vitamin B12 levels in children and adolescents on plant-based diets: a systematic review and meta-analysis

CONTEXT

The popularity of plant-based diets, characterized by a partial or complete exclusion of animal products, has increased significantly over the last 10 years. The exclusion of animal products removes the most common sources of vitamin B12, which can lead to vitamin B12 deficiency and result in irreversible damage, such as growth stunting.

OBJECTIVE

This aim of this systematic review and meta-analysis was to qualitatively evaluate all studies on this subject and to quantify the potential difference in vitamin B12 levels in healthy children and adolescents aged 5 to 18 years.

DATA SOURCES

PubMed and Embase databases were searched for relevant studies investigating vitamin B12 levels in healthy children and adolescents aged 5 to 18 years on plant-based diets.

DATA EXTRACTION

Studies were assessed qualitatively with the AXIS tool and quantitatively with Stata 16.0 software.

DATA ANALYSIS

Overall, children and adolescents on plant-based diets had a significantly lower vitamin B12 level than omnivorous children and adolescents (-97 pmol/L; 95%CI, -187 to -7; I2 = 98.5%), a difference that remained statistically significant after adjusting for methodological confounders. After subgroup analyses, this effect was not statistically significant for children and adolescents on vegetarian diets but remained significant in children and adolescents on vegan or macrobiotic diets. Moreover, total vitamin B12 intake nullified the mean difference in vitamin B12 levels.

CONCLUSION

Despite high heterogeneity across studies, these results indicate that children and adolescents on plant-based diets, especially those on vegan and macrobiotic diets, may be at risk of developing vitamin B12 deficiency.

The associations between stunting and wasting at 12 months of age and developmental milestones delays in a cohort of Cambodian children

Worldwide, over 250 million children under 5 years do not reach their developmental potential due to several causes, including malnutrition. In Cambodia, the prevalence of stunting and wasting among children remains high. This prospective cohort study aimed to assess acquisition of motor and cognitive developmental milestones in early childhood and their associations with stunting and wasting. Children aged from 0 to 24 months were recruited from three provinces in Cambodia and followed up to seven times from March 2016 to June 2019, until their 5 years. Data collection included anthropometry and developmental milestones. Seven motor and seven cognitive milestones were evaluated using the Cambodian Development Milestone Assessment Tool. Associations were assessed with parametric survival models. Hazard ratios (HR) below 1 stood for lower probabilities for achieving developmental milestones. Data were available for 7394 children. At 12 months, the prevalence of stunting and wasting were 23.7% and 9.6% respectively. Both were consistently associated with delays in most motor and cognitive milestones. Stunting was strongly associated with delays in gross motor milestones (HR < 0.85; p < 0.001). Wasting was more strongly associated with delays in fine motor development and most cognitive milestones (HR < 0.75; p < 0.001). Promoting nutritional programs in the first 1000 days to prevent malnutrition is essential to further the optimal growth and motor and cognitive development of Cambodian children.

Aerobic Fitness, B-Vitamins, and Weight Status Are Related to Selective Attention in Children

There is an increasing prevalence of poor health behaviors during childhood, particularly in terms of physical activity and nutrition. This trend has occurred alongside a growing body of evidence linking these behaviors to cognitive function. B-vitamins are thought to be particularly important in the neural development that occurs during pregnancy, as well as in healthy cognitive aging. However, much less is known regarding the role of B-vitamins during childhood. Given that preadolescent childhood is a critical period for cognitive development, this study investigated the relationship between specific aspects of nutrition, particularly B-vitamins, and related health factors (e.g., body mass, fitness) on selective attention in children. Children (n = 85; 8-11 years) completed a selective attention task to assess inhibition. Participant's dietary intake was collected using the Automated Self-Administered 24-h dietary assessment tool. Correlations between specific nutrients, BMI, fitness, and task performance were investigated. After accounting for demographic variables and total caloric intake, increased B-vitamin intake (i.e., thiamin and folic acid) was associated with shorter reaction times (p's < 0.05), fitness was associated with greater response accuracy (p < 0.05), and increased BMI was related to increased variability in reaction times (p < 0.05). Together, these findings suggest that aspects of health may have unique contributions on cognitive performance. Proper physical health and nutrition are imperative for effective cognitive functioning in preadolescent children. Targeted efforts aimed at health education amongst this population could ensure proper cognitive development during school-age years, providing a strong foundation throughout life.

The association of early linear growth and haemoglobin concentration with later cognitive, motor, and social-emotional development at preschool age in Ghana

It is important to identify the periods during childhood when exposure to environmental risk factors results in long-term neurodevelopmental deficits. Stunting and anaemia may be sensitive indicators of exposure to such risks. In a prospective cohort enrolled before birth, we investigated the association of developmental scores at 4-6 years with (a) birth length and linear growth during three postnatal periods and (2) haemoglobin (Hb) concentration at three time points. Children were participants in a follow-up study of a randomized controlled trial of nutritional supplementation in Ghana. At 4-6 years, cognitive, motor, and social-emotional developments were assessed using standard tests adapted for this population. We estimated the associations of length-for-age z-score (LAZ) at birth and postnatal linear growth (n = 710) and Hb (n = 617) with developmental scores in regression models, using multistage least squares analysis to calculate uncorrelated residuals for postnatal growth. Cognitive development at 4-6 years was significantly associated with LAZ at birth (β = 0.12, 95% CI = 0.05, 0.19), ΔLAZ from 6 to 18 months (β = 0.16, 95% CI = 0.04, 0.28), and Hb at 18 months (β = 0.13, 95% CI = 0.06, 0.20), but not with ΔLAZ during 0-6 months, ΔLAZ from 18 months to 4-6 years, Hb at 6 months, or Hb at 4-6 years. No evidence of associations with motor or social-emotional development were found. These results suggest that in similar contexts, the earlier periods prior to birth and up to 18 months are more sensitive to risk factors for long-term cognitive development associated with LAZ and Hb compared with later childhood. This may inform the optimal timing of interventions targeting improved cognitive development.

A Path Analysis of Nutrition, Stimulation, and Child Development Among Young Children in Bihar, India

Nutrition plays an important role in the development of a child, particularly in low‐ and middle‐income countries where malnutrition is often widespread. The relation between diet, hemoglobin, nutritional status, motor development, stimulation and mental development was examined in a cross‐sectional sample of 1,079 children 12–18 months of age living in rural Bihar, India. Path analysis revealed associations between (a) length‐for‐age z‐scores and motor development, standardized β (β) = .285, p < .001, and (b) motor and all mental development outcomes (language: β = .422; personal‐social: β = .490; memory: β = .139; and executive function: β = .072, all p < .001). Additionally, stimulation was significantly associated with language scores and hemoglobin concentration with memory. These findings inform interventions aimed at improving child development in Northern India.

Nutrition Status of Primary School Students in Two Rural Regions of Guinea-Bissau

BACKGROUND

The nutrition status of primary schoolchildren in Africa has received relatively little attention in comparison to that of younger children. We surveyed primary school students in Guinea-Bissau, a nation that is among the poorest in the world.

OBJECTIVE

Anthropometry and prevalence of anemia and vitamin A deficiency were assessed in schoolchildren participating in International Partnership for Human Development's school feeding program in 2 regions of Guinea-Bissau.

METHODS

A cross-sectional survey of 32 schools in the regions of Cacheu and Oio was conducted in November 2011. Variables included age, gender, weight, height, hemoglobin, and retinol-binding protein concentrations. Z scores for height for age (HAZ), body mass index for age (BAZ), and weight for age were calculated using World Health Organization reference data.

RESULTS

Anthropometric assessment of 4784 students revealed stunting (HAZ < -2) in 15.5%, thinness (BAZ < -2) in 13.2%, and anemia in 42.0%. Stunting, thinness, and anemia were significantly more common in males, in students from Oio, and in older students. Vitamin A deficiency, detected in 21.5% of the population, was the only assessment that did not demonstrate significant differences between genders or regions. About 61.1% of all children had 1 or more indicators of undernutrition.

CONCLUSION

There are substantial rates of stunting, thinness, underweight, anemia, and vitamin A deficiency in primary schoolchildren in Guinea-Bissau, even among those participating in a school lunch program and particularly among males and older students. The results suggest the need for evaluating feeding programs and other methods to improve nutrition status in primary school students, especially in older students.

Vitamin B-12 and Cognition in Children

Vitamin B-12 is essential for brain development, neural myelination, and cognitive function. Inadequate vitamin B-12 status during pregnancy and early childhood has been associated with adverse child health outcomes, including impaired cognitive development. However, the underlying mechanisms have not been elucidated. This review was conducted to examine the evidence that links vitamin B-12 and cognition in children. The search strategy resulted in 17 studies: 3 cross-sectional, 1 case-control, and 12 cohort studies, and 1 randomized trial. Cognitive processes assessed included attention, memory, and perception. Developmental outcomes, academic performance, and intelligence quotient were also considered. Despite the high prevalence of vitamin B-12 insufficiency and associated risk of adverse cognitive outcomes in children, to our knowledge, no studies to date have been conducted to examine the effects of vitamin B-12 supplementation on cognition in children. The role of vitamin B-12 in the etiology of child cognitive outcomes needs to be elucidated to inform public health interventions.

Effect of vitamin B12 and omega-3 fatty acid supplementation on brain neurotrophins and cognition in rats: A multigeneration study

Vitamin B12 and omega-3 fatty acids are important nutrients required for neuronal functioning. We have demonstrated the beneficial effects of vitamin B12 and omega-3 fatty acid supplementation on brain neurotrophins and cognition in the first and second generation offspring. However, there is a need to examine if the effects are sustained in the third generation offspring. This study reports the effects of vitamin B12 and omega-3 fatty acid supplementation across three consecutive generations on brain neurotrophins like brain derived neurotrophic factor (BDNF); nerve growth factor (NGF) and cognitive performance in the third generation male offspring. Three successive generations of Wistar rats were assigned the following groups throughout pregnancy, lactation and adulthood: i) Control, ii) vitamin B12 deficient (BD), iii) vitamin B12 deficient + omega-3 fatty acid (BDO), iv) vitamin B12 supplemented (BS) and v) vitamin B12 supplemented + omega-3 fatty acid (BSO). The BD group demonstrated lower (p < 0.01) NGF in the cortex but not BDNF levels although the cognition was impaired (p < 0.01). In contrast, in the BDO group, higher NGF levels were observed in the hippocampus and animals demonstrated improved (p < 0.01) cognitive performance. Vitamin B12 supplementation showed comparable BDNF levels in the hippocampus while their levels were lower in the cortex as compared to the control (p < 0.05). These animals showed more reference and working memory errors (p < 0.01) as compared to the control group. A combined supplementation of vitamin B12 and omega-3 fatty acid showed higher (p < 0.01) levels of DHA and NGF in the hippocampus, higher BDNF in both hippocampus and cortex and improved cognitive performance. Our findings have implications for fortification of foods with vitamin B12 and omega-3 fatty acids in improving brain development.

Effect of prenatal and postnatal malnutrition on intellectual functioning in early school-aged children in rural western China

The aim of this study was to evaluate the effect of prenatal and postnatal malnutrition on the intellectual functioning of early school-aged children. We followed the offspring of women who had participated in a trial of prenatal supplementation with different combinations of micronutrients and who remained resident in the study field. We measured their intellectual functioning using the Wechsler intelligence scale for children (WISC-IV). Height-for-age, weight-for-age, and body mass index (BMI)-for-age were used as anthropometric nutritional status indices. Four of the 5 composite scores derived from the WISC-IV, except for working memory index (WMI), were significantly lower in low birth weight children after adjusting for confounds. All 5 composite scores, including full-scale intelligence quotient (FSIQ), verbal comprehension index (VCI), WMI, perceptual reasoning index (PRI), and processing speed index (PSI) were significant lower in stunted and underweight children. The differences in the means of WISC-IV test scores were greatest between stunted and nonstunted children. The means for FSIQ, VCI, WMI, PRI, and PSI were as follows: 5.88 (95% confidence interval [CI]: 2.84-8.92), 5.08 (95% CI: 1.12-8.41), 4.71 (95% CI: 1.78-7.66), 6.13 (95% CI: 2.83-9.44), and 5.81 (95% CI: 2.61-9.00). These means were lower in stunted children after adjusting for confounds. Our results suggest the important influences of low birth weight and postnatal malnutrition (stunting, low body weight) on intellectual functioning in early school-aged children.

Novel insights into the effect of vitamin B₁₂ and omega-3 fatty acids on brain function

The prevalence of psychiatric disorders which are characterized by cognitive decline is increasing at an alarming rate and account for a significant proportion of the global disease burden. Evidences from human and animal studies indicate that neurocognitive development is influenced by various environmental factors including nutrition. It has been established that nutrition affects the brain throughout life. However, the mechanisms through which nutrition modulates mental health are still not well understood. It has been suggested that the deficiencies of both vitamin B12 and omega-3 fatty acids can have adverse effects on cognition and synaptic plasticity. Studies indicate a need for supplementation of vitamin B12 and omega-3 fatty acids to reduce the risk of cognitive decline, although the results of intervention trials using these nutrients in isolation are inconclusive. In the present article, we provide an overview of vitamin B12 and omega-3 fatty acids, the possible mechanisms and the evidences through which vitamin B12 and omega-3 fatty acids modulate mental health and cognition. Understanding the role of vitamin B12 and omega-3 fatty acids on brain functioning may provide important clues to prevent early cognitive deficits and later neurobehavioral disorders.

Vitamin B-12 Deficiency in Children Is Associated with Grade Repetition and School Absenteeism, Independent of Folate, Iron, Zinc, or Vitamin A Status Biomarkers

BACKGROUND

Micronutrients are essential to neurocognitive development; yet their role in educational outcomes is unclear.

OBJECTIVE

We examined the associations of micronutrient status biomarkers with the risk of grade repetition and rates of school absenteeism in a cohort of school children.

METHODS

We recruited 3156 children aged 5-12 y from public schools in Bogota, Colombia. Circulating ferritin, hemoglobin, zinc, vitamin A, and vitamin B-12; erythrocyte folate; and mean corpuscular volume (MCV) were measured in blood samples obtained at the beginning of the year. Absenteeism was recorded weekly during the school year, and grade repetition was determined the next year. Risk ratios for grade repetition and rate ratios for absenteeism were estimated by categories of micronutrient status indicators with use of Poisson regression, adjusting for potential confounders.

RESULTS

The risk of grade repetition was 4.9%, and the absenteeism rate was 3.8 d per child-year of observation. Vitamin B-12 deficiency (<148 pmol/L) was associated with an adjusted 2.36-fold greater risk of grade repetition (95% CI: 1.03, 5.41; P = 0.04) compared with plasma concentrations ≥148 pmol/L. Other micronutrients were not related to grade repetition. Vitamin B-12 deficiency was also associated with school absenteeism rates. Compared with children with plasma vitamin B-12 concentrations ≥148 pmol/L, vitamin B-12-deficient children had a 1.89-times higher adjusted rate (95% CI: 1.53, 2.34; P < 0.0001). Anemia was related to a 72% higher rate (95% CI: 48%, 99%; P < 0.0001), whereas every 5-fL difference in MCV was associated with a 7% lower adjusted rate (95% CI: 4%, 10%; P < 0.0001).

CONCLUSIONS

Vitamin B-12 deficiency was associated with risk of grade repetition and school absenteeism rates in school children from Bogota, Colombia. The effects of correcting vitamin B-12 deficiency on educational outcomes and neurocognitive development of school children need to be determined in intervention studies.

Linear growth and child development in low- and middle-income countries: a meta-analysis

BACKGROUND AND OBJECTIVE

The initial years of life are critical for physical growth and broader cognitive, motor, and socioemotional development, but the magnitude of the link between these processes remains unclear. Our objective was to produce quantitative estimates of the cross-sectional and prospective association of height-for-age z score (HAZ) with child development.

METHODS

Observational studies conducted in low- and middle-income countries (LMICs) presenting data on the relationship of linear growth with any measure of child development among children <12 years of age were identified from a systematic search of PubMed, Embase, and PsycINFO. Two reviewers then extracted these data by using a standardized form.

RESULTS

A total of 68 published studies conducted in 29 LMICs were included in the final database. The pooled adjusted standardized mean difference in cross-sectional cognitive ability per unit increase in HAZ for children ≤ 2 years old was +0.24 (95% confidence interval [CI], 0.14-0.33; I(2) = 53%) and +0.09 for children > 2 years old (95% CI, 0.05-0.12; I(2) = 78%). Prospectively, each unit increase in HAZ for children ≤ 2 years old was associated with a +0.22-SD increase in cognition at 5 to 11 years after multivariate adjustment (95% CI, 0.17-0.27; I(2) = 0%). HAZ was also significantly associated with earlier walking age and better motor scores (P < .05).

CONCLUSIONS

Observational evidence suggests a robust positive association between linear growth during the first 2 years of life with cognitive and motor development. Effective interventions that reduce linear growth restriction may improve developmental outcomes; however, integration with environmental, educational, and stimulation interventions may produce larger positive effects.

Omega-3 supplementation during the first 5 years of life and later academic performance: a randomised controlled trial

BACKGROUND/OBJECTIVES

Consumption of oily fish more than once per week has been shown to improve cognitive outcomes in children. However, it is unknown whether similar benefits can be achieved by long-term omega-3 fatty acid supplementation. The objective was to investigate the effect of omega-3 fatty acid supplementation during the first 5 years of life on subsequent academic performance in children by conducting a secondary analysis of the CAPS (Childhood Asthma Prevention Study).

SUBJECTS/METHODS

A total of 616 infants with a family history of asthma were randomised to receive tuna fish oil (high in long-chain omega-3 fatty acids, active) or Sunola oil (low in omega-3 fatty acids, control) from the time breastfeeding ceased or at the age of 6 months until the age of 5 years. Academic performance was measured by a nationally standardised assessment of literacy and numeracy (National Assessment Program Literacy and Numeracy (NAPLAN)) in school years 3, 5, 7 and 9. Plasma omega-3 fatty acid levels were measured at regular intervals until 8 years of age. Between-group differences in test scores, adjusted for maternal age, birth weight and maternal education, were estimated using mixed-model regression.

RESULTS

Among 239 children, there were no significant differences in NAPLAN scores between active and control groups. However, at 8 years, the proportion of omega-3 fatty acid in plasma was positively associated with the NAPLAN score (0.13 s.d. unit increase in score per 1% absolute increase in plasma omega-3 fatty acid (95% CI 0.03, 0.23)).

CONCLUSIONS

Our findings do not support the practice of supplementing omega-3 fatty acids in the diet of young children to improve academic outcomes. Further exploration is needed to understand the association between plasma omega-3 fatty acid levels at 8 years and academic performance.

Animal source foods have a positive impact on the primary school test scores of Kenyan schoolchildren in a cluster-randomised, controlled feeding intervention trial

Micronutrient deficiencies and suboptimal energy intake are widespread in rural Kenya, with detrimental effects on child growth and development. Sporadic school feeding programmes rarely include animal source foods (ASF). In the present study, a cluster-randomised feeding trial was undertaken to determine the impact of snacks containing ASF on district-wide, end-term standardised school test scores and nutrient intake. A total of twelve primary schools were randomly assigned to one of three isoenergetic feeding groups (a local plant-based stew (githeri) with meat, githeri plus whole milk or githeri with added oil) or a control group receiving no intervention feeding. After the initial term that served as baseline, children were fed at school for five consecutive terms over two school years from 1999 to 2001. Longitudinal analysis was used controlling for average energy intake, school attendance, and baseline socio-economic status, age, sex and maternal literacy. Children in the Meat group showed significantly greater improvements in test scores than those in all the other groups, and the Milk group showed significantly greater improvements in test scores than the Plain Githeri (githeri+oil) and Control groups. Compared with the Control group, the Meat group showed significant improvements in test scores in Arithmetic, English, Kiembu, Kiswahili and Geography. The Milk group showed significant improvements compared with the Control group in test scores in English, Kiswahili, Geography and Science. Folate, Fe, available Fe, energy per body weight, vitamin B₁₂, Zn and riboflavin intake were significant contributors to the change in test scores. The greater improvements in test scores of children receiving ASF indicate improved academic performance, which can result in greater academic achievement.

Relationship between anthropometric indicators and cognitive performance in Southeast Asian school-aged children

Nutrition is an important factor in mental development and, as a consequence, in cognitive performance. Malnutrition is reflected in children's weight, height and BMI curves. The present cross-sectional study aimed to evaluate the association between anthropometric indices and cognitive performance in 6746 school-aged children (aged 6–12 years) of four Southeast Asian countries: Indonesia; Malaysia; Thailand; Vietnam. Cognitive performance (non-verbal intelligence quotient (IQ)) was measured using Raven's Progressive Matrices test or Test of Non-Verbal Intelligence, third edition (TONI-3). Height-for-age z-scores (HAZ), weight-for-age z-scores (WAZ) and BMI-for-age z-scores (BAZ) were used as anthropometric nutritional status indices. Data were weighted using age, sex and urban/rural weight factors to resemble the total primary school-aged population per country. Overall, 21 % of the children in the four countries were underweight and 19 % were stunted. Children with low WAZ were 3·5 times more likely to have a non-verbal IQ < 89 (OR 3·53 and 95 % CI 3·52, 3·54). The chance of having a non-verbal IQ < 89 was also doubled with low BAZ and HAZ. In contrast, except for severe obesity, the relationship between high BAZ and IQ was less clear and differed per country. The odds of having non-verbal IQ levels < 89 also increased with severe obesity. In conclusion, undernourishment and non-verbal IQ are significantly associated in 6–12-year-old children. Effective strategies to improve nutrition in preschoolers and school-aged children can have a pronounced effect on cognition and, in the longer term, help in positively contributing to individual and national development.

Micronutrient deficiency and cognitive and physical performance in Indian children

Several micronutrient deficiencies affect functional, particularly cognition and physical performance of children. Identifying and preventing sub-clinical deficiencies may be important so that adverse effects on functional performance by these deficiencies, particularly of iron and the B vitamins, are prevented. There is also the potential for childhood micronutrient deficiencies to have long-term effects that affect health and productivity in adulthood. This is especially relevant in a developing country such as India, which faces the dual burden of malnutrition and where the prevalence of these deficiencies is high. This review highlights the extent of micronutrient deficiencies in Indian children and focuses on the effect of deficiencies of the B vitamins and iron on cognitive and physical performance in children. Most studies on multiple micronutrient supplementation or fortification in Indian school children show modest effects on cognitive and physical performance, and it is relevant to point out that these studies have largely been conducted on urban children with mild deficiency at most; children with moderate or severe deficiency have not been studied. However, diets of rural children indicate large deficits in micronutrient intake, particularly of folic acid, riboflavin and iron, and their consequences have not been studied. With the limited evidence available, a short term but economical solution to ensure adequate micronutrient intakes could be through the fortification of staple cereals taken throughout the day. As increasing household incomes translate into an increase in food expenditure and diet diversification, it may become necessary to define upper limits of intake for nutrients in India, particularly as many commercial foods are fortified.

Association between vitamin B12intake and EURRECA's prioritized biomarkers of vitamin B12in young populations: a systematic review

Objective

To review evidence on the associations between vitamin B12intake and its biomarkers, vitamin B12intake and its functional health outcomes, and vitamin B12biomarkers and functional health outcomes.

Design

A systematic review was conducted by searching electronic databases, until January 2012, using a standardized strategy developed in the EURRECA network. Relevant articles were screened and sorted based on title and abstract, then based on full text, and finally included if they met inclusion criteria. A total of sixteen articles were included in the review.

Setting

Articles covered four continents: America (n4), Europe (n8), Africa (n1) and Asia (n3).

Subjects

Population groups included healthy infants, children and adolescents, and pregnant and lactating women.

Results

From the total number of 5815 papers retrieved from the initial search, only sixteen were eligible according to the inclusion criteria: five for infants, five for children and adolescents, and six for pregnant and lactating women.

Conclusions

Only one main conclusion could be extracted from this scarce number of references: a positive association between vitamin B12intake and serum vitamin B12in the infant group. Other associations were not reported in the eligible papers or the results were not provided in a consistent manner. The low number of papers that could be included in our systematic review is probably due to the attention that is currently given to research on vitamin B12in elderly people. Our observations in the current systematic review justify the idea of performing well-designed studies on vitamin B12in young populations.

Maternal intake of methyl-donor nutrients and child cognition at 3 years of age

Methyl-donor nutrients are substrates for methylation reactions involved in neurodevelopment processes. The role of maternal intake of these nutrients on cognitive performance of the offspring is poorly understood. We examined the associations of maternal intake of folate, vitamin B12, choline, betaine and methionine during the first and second trimesters of pregnancy, with tests of cognitive performance in the offspring at 3 years of age using data from 1210 participants in Project Viva, a prospective pre-birth cohort study in Massachusetts. We assessed nutrient intake with the use of food frequency questionnaires. Children's cognition at age 3 years was evaluated with the Peabody Picture Vocabulary Test III (PPVT-III) and visual-motor skills with the Wide Range Assessment of Visual Motor Abilities test. In multivariable models adjusting for potential sociobehavioural and nutritional confounders, for each 600 µg/day increment in total folate intake during the first trimester, PPVT-III score at age 3 years was 1.6 points [95% confidence interval (CI) 0.1, 3.1; P = 0.04] higher. There was a weak inverse association between vitamin B12 intake during the second trimester and PPVT-III scores [-0.4 points per 2.6 µg/day; 95% CI -0.8, -0.1; P = 0.01]. We did not find associations between choline, betaine or methionine and cognitive outcomes at this age. Results of this study suggest that higher intake of folate in early pregnancy is associated with higher scores on the PPVT-III, a test of receptive language that predicts overall intelligence, at age 3 years.

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.