Folate, related B vitamins, and homocysteine in childhood and adolescence: potential implications for disease risk in later life

Factors influencing vitamin B6 status in domestic cats: age, disease, and body condition score

Limited studies are available on vitamin B6 status in domestic cats. To this end, we evaluated glutamate-oxaloacetate transaminase (GOT) activity in hemolysates with and without pyridoxal 5'-phosphate addition in two feline populations: a cohort of 60 healthy, domestic (sexually intact and specific pathogen-free) cats maintained under strictly controlled conditions with appropriate diets housed at the Feline Nutrition and Pet Care Center, and a cohort of 57 cats randomly selected between December 2022 to January 2023 that visited the Veterinary Medicine Teaching Hospital to seek care under different circumstances. The GOT activity expressed as the ratio with and without pyridoxal 5'-phosphate addition (primary activation ratio; PAR) decreased significantly with age in the healthy cohort. The PAR values normalized to age established a cut-off for vitamin B6 deficiency in both cohorts, identifying 17 of 101 animals as vitamin B6 deficient. Using machine learning, a partition-based model (decision tree) was built to identify the most important factors that predicted vitamin B6 deficiency while using the resulting tree to make predictions for new observations. This analysis, performed with all 101 cats, revealed that the diagnosis of an infectious, chronic or acute condition (0.55) was the main contributor, followed by age (0.26), and body condition score (optimal-overweight; 0.19). Thus, our study supports that vitamin B6 supplementation may be indicated in junior to adult animals diagnosed with an infectious, chronic, or acute conditions or healthy cats with body weight ranging from optimal to overweight. In older cats, even if healthy, underweight to optimal cats appear to be at risk of vitamin B6 deficiency.

Scientific opinion on the tolerable upper intake level for folate

Following a request from the European Commission (EC), the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the revision of the tolerable upper intake level (UL) for folic acid/folate. Systematic reviews of the literature were conducted to assess evidence on priority adverse health effects of excess intake of folate (including folic acid and the other authorised forms, (6S)-5-methyltetrahydrofolic acid glucosamine and l-5-methyltetrahydrofolic acid calcium salts), namely risk of cobalamin-dependent neuropathy, cognitive decline among people with low cobalamin status, and colorectal cancer and prostate cancer. The evidence is insufficient to conclude on a positive and causal relationship between the dietary intake of folate and impaired cognitive function, risk of colorectal and prostate cancer. The risk of progression of neurological symptoms in cobalamin-deficient patients is considered as the critical effect to establish an UL for folic acid. No new evidence has been published that could improve the characterisation of the dose-response between folic acid intake and resolution of megaloblastic anaemia in cobalamin-deficient individuals. The ULs for folic acid previously established by the Scientific Committee on Food are retained for all population groups, i.e. 1000 μg/day for adults, including pregnant and lactating women, 200 μg/day for children aged 1-3 years, 300 μg/day for 4-6 years, 400 μg/day for 7-10 years, 600 μg/day for 11-14 years and 800 μg/day for 15-17 years. A UL of 200 μg/day is established for infants aged 4-11 months. The ULs apply to the combined intake of folic acid, (6S)-5-methyltetrahydrofolic acid glucosamine and l-5-methyltetrahydrofolic acid calcium salts, under their authorised conditions of use. It is unlikely that the ULs for supplemental folate are exceeded in European populations, except for regular users of food supplements containing high doses of folic acid/5-methyl-tetrahydrofolic acid salts.

Causes and Clinical Sequelae of Riboflavin Deficiency

Riboflavin, in its cofactor forms flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), plays fundamental roles in energy metabolism, cellular antioxidant potential, and metabolic interactions with other micronutrients, including iron, vitamin B6, and folate. Severe riboflavin deficiency, largely confined to low-income countries, clinically manifests as cheilosis, angular stomatitis, glossitis, seborrheic dermatitis, and severe anemia with erythroid hypoplasia. Subclinical deficiency may be much more widespread, including in high-income countries, but typically goes undetected because riboflavin biomarkers are rarely measured in human studies. There are adverse health consequences of low and deficient riboflavin status throughout the life cycle, including anemia and hypertension, that could contribute substantially to the global burden of disease. This review considers the available evidence on causes, detection, and consequences of riboflavin deficiency, ranging from clinical deficiency signs to manifestations associated with less severe deficiency, and the related research, public health, and policy priorities.

Plasma homocysteine levels and associated factors in community-dwelling adolescents: the EVA-TYROL study

Background

Homocysteine (Hcy) has been associated with an adverse cardiovascular risk profile in adolescents. Assessment of the association between plasma Hcy levels and clinical/laboratory factors might improve our understanding of the pathogenesis of cardiovascular disease.

Methods

Hcy was measured in 1,900 14- to 19-year-old participants of prospective population-based EVA-TYROL Study (44.3% males, mean age 16.4 years) between 2015 and 2018. Factors associated with Hcy were assessed by physical examination, standardized interviews, and fasting blood analysis.

Results

Mean plasma Hcy was 11.3 ± 4.5 µmol/L. Distribution of Hcy was characterized by extreme right skew. Males exhibited higher Hcy and sex differences increased with increasing age. Univariate associations with Hcy emerged for age, sex, body mass index, high-density lipoprotein cholesterol, and for factors pertaining to blood pressure, glucose metabolism, renal function, and diet quality, whereas the most important multivariate predictors of Hcy were sex and creatinine.

Discussion

Clinical and laboratory factors associated with Hcy in adolescents were manifold, with sex and high creatinine identified as strongest independent determinants. These results may aid when interpreting future studies investigating the vascular risk of homocysteine.

Dried blood spot reference intervals for 18 amino acids in a 1 to 6 years old pediatric cohort

OBJECTIVES

Reference intervals are indispensable for the accurate clinical interpretation of clinical laboratory tests. The reference intervals of amino acids in dried blood spots (DBS) from nonnewborn children are limited. In this study, we aim to establish the pediatric reference intervals for amino acids in DBS from healthy Chinese children aged from 1 to 6 years and to investigate the effect of sex and age.

DESIGN AND METHODS

In 301 healthy subjects aged from 1 to 6 years old, eighteen DBS amino acids were determined using ultra-performance chromatography-tandem mass spectrometry method. Amino acid concentrations were examined in relation to sex and age. Reference intervals were established according to the CLSI C28-A3 guidelines.

RESULTS

Reference intervals of 18 amino acids bounded by the 2.5 and 97.5 percentiles were calculated in DBS specimen. No significant influence of age was observed for all the target amino acid concentrations in 1- to 6-year-olds. Sex differences were found in leucine and aspartic acid.

CONCLUSIONS

The RIs established in the present study added value for diagnosing and managing the amino acid-related diseases in the pediatric population.

Daily Folic Acid and/or Vitamin B12 Supplementation Between 6 and 30 Months of Age and Cardiometabolic Risk Markers After 6-7 Years: A Follow-Up of a Randomized Controlled Trial

BACKGROUND

Deficiencies of vitamin B12 and folate are associated with elevated concentrations of metabolic markers related to CVDs.

OBJECTIVES

We investigated the effect of supplementation of vitamin B12 with or without folic acid for 6 mo in early childhood on cardiometabolic risk markers after 6-7 y.

METHODS

This is a follow-up study of a 2 × 2 factorial, double-blind, randomized controlled trial of vitamin B12 and/or folic acid supplementation in 6-30-mo-old children. The supplement contained 1.8 μg of vitamin B12, 150 μg of folic acid, or both, constituting >1 AI or recommended daily allowances for a period of 6 mo. Enrolled children were contacted again after 6 y (September 2016-November 2017), and plasma concentrations of tHcy, leptin, high molecular weight adiponectin, and total adiponectin were measured (N = 791).

RESULTS

At baseline, 32% of children had a deficiency of either vitamin B12 (<200 pmol/L) or folate (<7.5 nmol/L). Combined supplementation of vitamin B12 and folic acid resulted in 1.19 μmol/L (95% CI: 0.09; 2.30 μmol/L) lower tHcy concentration 6 y later compared to placebo. We also found that vitamin B12 supplementation was associated with a lower leptin-adiponectin ratio in subgroups based on their nutritional status.

CONCLUSIONS

Supplementation with vitamin B12 and folic acid in early childhood was associated with a decrease in plasma tHcy concentrations after 6 y. The results of our study provide some evidence of persistent beneficial metabolic effects of vitamin B12 and folic acid supplementation in impoverished populations. The original trial was registered at www.

CLINICALTRIALS

gov as NCT00717730, and the follow-up study at www.ctri.nic.in as CTRI/2016/11/007494.

Serum pyridoxine, folate, cobalamin, and homocysteine levels in children presenting with vasovagal syncope

BACKGROUND

Recent studies confirm the role of B vitamins deficiency and hyperhomocysteinaemia in the development of dysautonomia that has been considered to be the main factor in vasovagal syncope development. The aim of the study was to investigate serum pyridoxine, folate, cobalamin, and homocysteine levels in children presenting with vasovagal syncope and to analyse the correlation between them and main clinical parameters of syncope.

METHODS

We studied 40 children, ages 8-17 years with a history of vasovagal syncope and 24 healthy volunteers. The serum pyridoxine, folate, cobalamin, and homocysteine levels were measured by a quantitative sandwich enzyme immunoassay technique using a commercial kit (Monobind, USA). Twenty-four-hour Holter monitoring and 24-hour ambulatory blood pressure monitoring were conducted for all participated patients.

RESULTS

Serum pyridoxine (9.42 ± 4.87, 16.11 ± 5.53 µg/L) and cobalamin (307.48 ± 95.50, 447.28 ± 108.85 ng/L) levels were reasonably low (p < 0.05) in patients with vasovagal syncope. Although there was no significant change in folate levels between syncope and healthy children (4.00 ± 1.34, 4.71 ± 1.73 µg/L; p = 0.20), we detected low folate-level association with longer duration of syncope (r = -0.42) and post syncope (r = -0.43) symptoms (p < 0.05). Finally, there was increased serum homocysteine level (13.55 ± 5.03, 7.81 ± 1.71 µmol/L; p < 0.05) in patients with vasovagal syncope. It was positively correlated with the average PQ interval (r = 0.35, p < 0.05) and average QTc interval (r = 0.49, p < 0.05).

CONCLUSIONS

The results suggested that pyridoxine, folate, cobalamin, and homocysteine may be involved in the pathogenesis of vasovagal syncope. This might provide a new approach for effective treatment of paediatric vasovagal syncope, requiring further study.

Adolescent Afghan Refugees Display a High Prevalence of Hyperhomocysteinemia and Associated Micronutrients Deficiencies Indicating an Enhanced Risk of Cardiovascular Disease in Later Life

A growing body of research evidence suggests that elevated homocysteine level (hyperhomocysteinemia) is an independent risk factor for cardiovascular diseases. The current study aimed to investigate the prevalence and associated risk factors for hyperhomocysteinemia among adolescent Afghan refugees aged 10−19 years. In total, 206 healthy adolescent boys and girls were randomly recruited from a refugee village in Peshawar, Pakistan, in 2020. Socio-demographic data, anthropometric assessment, and blood sample collection were performed following standard methods. Serum homocysteine was assessed using a chemiluminescent microparticle immunoassay, with hyperhomocysteinemia defined as levels ≥ 15 µmol/L. The overall prevalence of hyperhomocysteinemia was 25%, with mean homocysteine levels significantly (p = 0.004) higher among boys (14.1 µmol/L) than girls (11.8 µmol/L). Multivariate logistic regression analysis revealed a significant association between hyperhomocysteineimia and serum levels of vitamin B12 (OR 0.29; 95% CI of 0.14 to 0.62; p < 0.01) and folate (OR 0.1; 95% CI of 0.03 to 0.27; p < 0.001). Overall, our study findings indicate high prevalence of hyperhomocysteinemia among adolescent Afghan refugees who are potentially at high risk of developing cardiovascular diseases in future. There is a dire need to develop and implement nutritional and public health strategies to control hyperhomocysteinemia, protect against related diseases and complications in future, and ensure healthy lives and well-being among these vulnerable populations.

Age and seasonal variation and establishment of reference intervals for water-soluble vitamins determined by liquid chromatography tandem mass spectrometry

OBJECTIVES

We aimed to establish reference intervals for water-soluble vitamins determined by liquid chromatography tandem mass spectrometry to improve the diagnosis of vitamin deficiency and outcomes of associated conditions.

METHODS

In this retrospective analysis of 24 810 specimens, we aimed to examine sex-, age-, and season-related variations in vitamin levels in different groups, set reference-value intervals for vitamin levels, and evaluate these reference values against those recommended by manufacturers.

RESULTS

Levels of vitamins B₃, B₅, B₆, B₇, and B₁₂ were higher, and those of vitamins B₂, B₉, and C were lower, in men than in women. There were seasonal variations in levels of vitamins B₁, B₃, B₅, B₆, B₉, B₁₂, and C. Levels of vitamins B₁, B₂, B₃, B₅, B₆, B₇, B₉, and C differed across age groups; vitamin B₁ displayed significant differences between ages 0 to 14 years and adults compared with reference change values. The lower limits of vitamins B₁ (ages 15-100 y), B₂, B₃, B₇, and C were lower, and that of vitamin B₅ was higher, than the recommended reference values. Finally, the upper limits of vitamins B₁, B₃, B₅, B₆, and B₇ were lower than the recommended values.

CONCLUSIONS

For values obtained using liquid chromatography tandem mass spectrometry, the lower limits of reference intervals for vitamins B₁ (ages 15-100 y), B₂, B₃, B₇, and C should be lowered, that of vitamin B₅ should be raised, and the upper limits of reference intervals for vitamins B₁, B₃, B₅, B₆, and B₇ should be lowered.

Dietary Determinants of Anemia in Children Aged 6-36 Months: A Cross-Sectional Study in Indonesia

Anemia has been acknowledged as worldwide problem, including in Indonesia. This cross-sectional study aims to explore dietary determinants as risk factors for anemia in children aged 6–36 months living in a poor urban area of Jakarta. The study was done in Kampung Melayu sub-district in Jakarta, Indonesia. Data was collected within two weeks in September–October 2020. A structured questionnaire for a 24-h recall and a semi-quantitative Food Frequency Questionnaire (FFQ) were used to collect the dietary intake data, and venous blood was withdrawn to determine the hemoglobin levels. Bivariate chi-square and multiple logistic regression tests were executed to explore the dietary determinant factors for anemia. We recruited 180 subjects. The average hemoglobin concentration was 11.4 ± 1.7 mg/dL; the anemia prevalence was 29.4%. The following variables were significantly associated with higher risk of anemia: no cow’s milk formula consumption, inadequate intake of fats, protein, calcium, vitamin D, iron, zinc, vitamin A, vitamin C, vitamin B6, and vitamin B12. Only cow’s milk formula consumption and zinc intake were revealed as the determinant factors of anemia. In conclusion, the prevalence of anemia was 29.4% among children aged 6–36 months old. Anemia was significantly associated with two dietary determinants as risk factors that are cow’s milk formula consumption and zinc intake.

Status of folate in healthy children in Almeria

The objective of this study is to establish reference values for folic acid in a healthy population of children aged 4-11 years and to examine related epidemiological, dietary and analytical factors. A cross-sectional study of 658 healthy children aged 4-11 years was made. Epidemiological, socioeconomic and dietary variables were analysed, the BMI Z-score was obtained, levels of serum folate and serum vitamin B₁₂ were determined and haematological, iron status and erythropoietic activity parameters were examined. The study data were analysed by non-parametric tests and linear multiple regression. The mean folate value was 8.6 ± 4.6 ng/mL (95% reference interval: 2.8-20 ng/mL). A level < 3 ng/mL (5th percentile) was considered as folate deficiency (4.6% of subjects). No child reported symptoms related to this deficiency. Folate values were significantly lower with age (p < 0.01), low NSE and low parental educational level (p: 0.0001). No relationship was found between folates and the analytical variables. According to multivariate linear regression, the variables significantly associated with serum folate were age, socioeconomic level and vitamin B₁₂.Conclusions: Serum folate levels in healthy school children are described. Age, socioeconomic level and serum vitamin B₁₂ are factors associated with folate status. Specific cut-off values for a paediatric population should be defined. What is Known: • Folic acid is an essential micronutrient for optimal growth and development; its deficit is associated with adverse health effects. • The studies on their status and deficit are not comparable due to a lack of agreement on appropriate indicators and reference values. What is New: • This study reports the levels of serum folate in a large population of healthy schoolchildren, with strict inclusion criteria in a developed country and identifies the associated sociodemographic, dietary and analytical (vitamin B12, iron parameters and erythropoietic activity) factors, avoiding potential confusion.

Effects of maternal folic acid supplementation during the second and third trimesters of pregnancy on neurocognitive development in the child: an 11-year follow-up from a randomised controlled trial

BACKGROUND

Maternal folic acid (FA) supplementation before and in early pregnancy prevents neural tube defects (NTD), but it is uncertain whether continuing FA after the first trimester has benefits on offspring health. We aimed to evaluate the effect of FA supplementation throughout pregnancy on cognitive performance and brain function in the child.

METHODS

Follow-up investigation of 11-year-old children, residing in Northern Ireland, whose mothers had participated in a randomised trial of Folic Acid Supplementation in the Second and Third Trimesters (FASSTT) in pregnancy and received 400 μg/day FA or placebo from the 14th gestational week. Cognitive performance (Full Scale Intelligence Quotient, Verbal Comprehension, Working Memory, Perceptual Reasoning, and Processing Speed) was assessed using the Wechsler Intelligence Scale for Children. Neuronal function was assessed using magnetoencephalographic (MEG) brain imaging.

RESULTS

Of 119 mother-child pairs in the FASSTT trial, 68 children were assessed for neurocognitive performance at 11-year follow-up (Dec 2017 to Nov 2018). Children of mothers randomised to FA compared with placebo scored significantly higher in two Processing Speed tests, i.e. symbol search (mean difference 2.9 points, 95% CI 0.3 to 5.5, p = 0.03) and cancellation (11.3 points, 2.5 to 20.1, p = 0.04), whereas the positive effect on Verbal Comprehension was significant in girls only (6.5 points, 1.2 to 11.8, p = 0.03). MEG assessment of neuronal responses to a language task showed increased power at the Beta (13-30 Hz, p = 0.01) and High Gamma (49-70 Hz, p = 0.04) bands in children from FA-supplemented mothers, suggesting more efficient semantic processing of language.

CONCLUSIONS

Continued FA supplementation in pregnancy beyond the early period currently recommended to prevent NTD can benefit neurocognitive development of the child. MEG provides a non-invasive tool in paediatric research to objectively assess functional brain activity in response to nutrition and other interventions.

TRIAL REGISTRATION

ISRCTN ISRCTN19917787 . Registered on 15 May 2013.

Folate and Cobalamin Serum Levels in Healthy Children and Adolescents and Their Association with Age, Sex, BMI and Socioeconomic Status

This study proposes age- and sex-specific percentiles for serum cobalamin and folate, and analyzes the effects of sex, age, body mass index (BMI), and socioeconomic status (SES) on cobalamin and folate concentrations in healthy children and adolescents. In total, 4478 serum samples provided by healthy participants (2 months-18.0 years) in the LIFE (Leipzig Research Centre for Civilization Diseases) Child population-based cohort study between 2011 and 2015 were analyzed by electrochemiluminescence immunoassay (ECLIA). Continuous age-and sex-related percentiles (2.5th, 10th, 50th, 90th, 97.5th) were estimated, applying Cole's LMS method. In both sexes, folate concentrations decreased continuously with age, whereas cobalamin concentration peaked between three and seven years of age and declined thereafter. Female sex was associated with higher concentrations of both vitamins in 13- to 18-year-olds and with higher folate levels in one- to five-year-olds. BMI was inversely correlated with concentrations of both vitamins, whilst SES positively affected folate but not cobalamin concentrations. To conclude, in the assessment of cobalamin and folate status, the age- and sex-dependent dynamic of the respective serum concentrations must be considered. While BMI is a determinant of both vitamin concentrations, SES is only associated with folate concentrations.

Dietary Intake and Biomarkers of Folate and Cobalamin Status in Norwegian Preschool Children: The FINS-KIDS Study

BACKGROUND

Folate and cobalamin (vitamin B-12) are essential for growth and development. However, few population-based studies have investigated B-vitamin status in children.

OBJECTIVES

This study aimed to assess biomarkers of folate and vitamin B-12 status and to explore their dietary determinants in healthy Norwegian children.

METHODS

Using baseline data obtained from a randomized controlled trial on the effect of fish intake on neurodevelopment in children aged 4-6 y, we measured the plasma concentrations of folate, cobalamin, total plasma homocysteine (tHcy), and methylmalonic acid (MMA). Food-frequency questionnaires (FFQs) were used to assess dietary intake. We used unadjusted and multiple linear regression models to explore the determinants of biomarker concentrations.

RESULTS

The median (IQR) of plasma folate (n = 197) and plasma cobalamin (n = 195) concentrations were 15.2 (12.2-21.1) nmol/L and 785 (632-905) pmol/L, respectively. Plasma folate concentrations of <10 nmol/L were observed in 13% of the children. No child had a cobalamin concentration <148 pmol/L. Two children were identified with elevated plasma MMA concentrations (>0.26 μmol/L) and 8 children had elevated tHcy concentrations (>6.5 μmol/L). Plasma folate concentration was inversely correlated with tHcy (ρ = -0.24, P < 0.001); we found no correlation between tHcy and cobalamin (ρ = -0.075, P = 0.30). Children who consumed vitamin supplements had 51% higher plasma folate concentrations (P < 0.0001) than those who did not. Consumption of red meat for dinner more than twice a week was associated with 23% lower plasma folate (P < 0.01). No other significant associations between dietary intake and the biomarkers were observed.

CONCLUSIONS

The Norwegian preschool children from this cohort had adequate vitamin B-12 status. Poor folate status was common and associated with elevated tHcy. The implications of poor folate status during childhood should be a prioritized research question. This trial was registered at ClinicalTrials.gov as NCT02331667.

Altered Folate Homeostasis in Children with Down Syndrome: A Potential Basis for Enhanced Methotrexate Toxicity

Methotrexate is used to treat autoimmune and oncologic diseases in children with Down syndrome. However, increased methotrexate-related toxicity is reported in this population. We evaluated differences in the concentrations and distribution of erythrocyte folates in children with Down syndrome as a potential basis for this enhanced toxicity.

Addressing optimal folate and related B-vitamin status through the lifecycle: health impacts and challenges

The functional effects of folate within C1 metabolism involve interrelationships with vitamin B12, vitamin B6 and riboflavin, and related gene–nutrient interactions. These B vitamins have important roles throughout life, from pregnancy, through childhood, to middle and older age. Achieving optimal nutritional status for preventing folate-related disease is challenging, however, primarily as a result of the poor stability and incomplete bioavailability of folate from natural food sources when compared with the synthetic vitamin form, folic acid. Thus, in European countries, measures to prevent neural tube defects (NTD) have been largely ineffective because of the generally poor compliance of women with folic acid supplementation as recommended before and in early pregnancy. In contrast, countries worldwide with mandatory folic acid fortification policies have experienced marked reductions in NTD. Low vitamin B12 status is associated with increased risk of cognitive dysfunction, CVD and osteoporosis. Achieving optimal B12 status can be problematic for older people, however, primarily owing to food-bound B12 malabsorption which leads to sub-clinical deficiency even with high dietary B12 intakes. Optimising B-vitamin intake may be particularly important for sub-populations with impaired folate metabolism owing to genetic characteristics, most notably the 677C→T variant in the gene encoding the enzyme methylenetetrahydrofolate reductase (MTHFR). This common folate polymorphism is linked with several adverse health outcomes, including stroke, however, recent evidence has identified its novel interaction with riboflavin (the MTHFR cofactor) in relation to blood pressure and risk of developing hypertension. This review addresses why and how the optimal status of folate-related B vitamins should be achieved through the lifecycle.

Mining the Age-Dependent Reference Intervals of B Vitamins from Routine Laboratory Test Results

Objective

To describe the reference intervals of folate, vitamin B12, vitamin B6, and vitamin B1 by sex and age.

Methods

The study was performed by gathering data on 55,811 subjects from 57 medical centers. Groups were categorized based on age and grouped according to statistical significance values. The reference values for the different groups were determined using the Bhattacharya and Hoffmann methods.

Results

Vitamin B1 and B6 values and folate (vitamin B9) levels between the sexes were statistically significantly increased in the group aged 0 to 10 years. Likewise, we witnessed a similar increase in vitamin B12 levels in the group aged 0 to 5 years. However, low vitamin B6 levels (P <.001) were detected in nongeriatric patients (aged 0-60 years), and the reference intervals (3.4-41.9 µg/L) also were significantly different from those in the geriatric group (aged 61-100 years; 2.0-29.4 µg/L).

Conclusion

A lower vitamin B6 reference limit allows detection of subclinical vitamin deficiency more precisely in the geriatric group; respective reference intervals should be revised accordingly.

Do dietary patterns determine levels of vitamin B6, folate, and vitamin B12 intake and corresponding biomarkers in European adolescents? The Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study

OBJECTIVES

To determine dietary patterns (DPs) and explain the highest variance of vitamin B6, folate, and B12 intake and related concentrations among European adolescents.

METHODS

A total of 2173 adolescents who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence study met the eligibility criteria for the vitamin B intake analysis (46% boys) and 586 adolescents for the biomarkers analysis (47% boys). Two non-consecutive, 24-h, dietary recalls were used to assess the mean intakes. Concentrations were measured by chromatography and immunoassay testing. A reduced rank regression was applied to elucidate the combined effect of food intake of vitamin B and related concentrations.

RESULTS

The identified DPs (one per vitamin B intake and biomarker and by sex) explained a variability between 34.2% and 23.7% of the vitamin B intake and between 17.2% and 7% of the biomarkers. In the reduced rank regression models, fish, eggs, cheese, whole milk and buttermilk intakes were loaded positively for vitamin B intake in both sexes; however, soft drinks and chocolate were loaded negatively. For the biomarkers, a higher variability was observed in the patterns in terms of food loads such as alcoholic drinks, sugars, and soft drinks. Some food items were loaded differently between intakes and biomarkers such as fish products, which was loaded positively for intakes but negatively for plasma folate in girls.

CONCLUSIONS

The identified DPs explained up to 34.2% and 17.2% of the variability of the vitamin B intake and plasma concentrations, respectively, in European adolescents. Further studies are needed to elucidate the factors that determine such patterns.

Tongue Abnormalities Are Associated to a Maternal Folic Acid Deficient Diet in Mice

It is widely accepted that maternal folic acid (FA) deficiency during pregnancy is a risk factor for abnormal development. The tongue, with multiple genes working together in a coordinated cascade in time and place, has emerged as a target organ for testing the effect of FA during development. A FA-deficient (FAD) diet was administered to eight-week-old C57/BL/6J mouse females for 2–16 weeks. Pregnant dams were sacrificed at gestational day 17 (E17). The tongues and heads of 15 control and 210 experimental fetuses were studied. In the tongues, the maximum width, base width, height and area were compared with width, height and area of the head. All measurements decreased from 10% to 38% with increasing number of weeks on maternal FAD diet. Decreased head and tongue areas showed a harmonic reduction (Spearman nonparametric correlation, Rho = 0.802) with respect to weeks on a maternal FAD diet. Tongue congenital abnormalities showed a 10.9% prevalence, divided in aglossia (3.3%) and microglossia (7.6%), always accompanied by agnathia (5.6%) or micrognathia (5.2%). This is the first time that tongue alterations have been related experimentally to maternal FAD diet in mice. We propose that the tongue should be included in the list of FA-sensitive birth defect organs due to its relevance in several key food and nutrition processes.

Dietary sources and intakes of folates and vitamin B12 in the Spanish population: Findings from the ANIBES study

Background

Folates and vitamin B₁₂ are key nutrients in one-carbon metabolism and related diseases. Updated and plausible information on population intakes and their major dietary sources is scarce and urgently needed in Spain in order to increase the knowledge that can lead as previous step to prevention by fortification and supplementation policies.

Aims

The present study aims to evaluate main dietary folate and vitamin B₁₂ sources and intakes in the Spanish population.

Materials and methods

Results were derived from the ANIBES cross-sectional study using a nationally representative sample of the Spanish population (9–75 years, n = 2,009).

Results

Food groups with the highest mean proportional contribution to total folate intakes in both males and females were vegetables (21.7–24.9%) and cereals (10.7–11.2%), while meat and meat products (26.4%) and milk and dairy products (27.3%) were for B₁₂. Total median folate and B₁₂ intakes amongst women were 156.3 μg/d and 4.0 μg/d while for men were 163.6 μg/d and 4.5 μg/d, respectively. In all age groups, vitamin intakes were significantly higher in plausible than in non-plausible energy reporters.

Conclusion

A limited number of participants had adequate folate intakes, whereas vitamin B₁₂ intakes were adequate for practically the entire population. There is a clear need for improving folates intake in the Spanish population.

Foods contributing to vitamin B6, folate, and vitamin B12 intakes and biomarkers status in European adolescents: The HELENA study

PURPOSE

To examine the association between food groups consumption and vitamin B6, folate and B12 intakes and biomarkers in adolescents.

METHODS

In total 2189 individuals participating in the cross-sectional Healthy Lifestyle in Europe by Nutrition in Adolescence study met the eligibility criteria for analysis of dietary intakes (46 % males) and 632 for biomarker analysis (47 % males). Food intakes were assessed by two non-consecutive 24-h recalls. Biomarkers were measured by chromatography and immunoassay. Food groups which best discriminated participants in the extreme tertiles of the distribution of vitamins were identified by discriminant analyses. Food groups with standardised canonical coefficients higher or equal to 0.3 were selected as valid discriminators of vitamins intake and biomarkers extreme tertiles. Linear mixed model elucidated the association between food groups and vitamins intakes and biomarkers.

RESULTS

Vitamin B6 intakes and biomarkers were best discriminated by meat (males and females), margarine and mixed origin lipids only in males and breakfast cereals (females). Breakfast cereals (males), and fruits, margarine and mixed origin lipids, vegetables excluding potatoes, breakfast cereals, and soups/bouillon (females) determined the most folate intakes and biomarkers. Considering vitamin B12 intakes and biomarkers, meat, and white and butter milk (males and females), snacks (males), and dairy products (females) best discriminated individual in the extremes of the distribution. Fewer associations were obtained with mixed model for biomarkers than for vitamins intakes with food groups.

CONCLUSIONS

Whereas B-vitamin intakes were associated with their food sources, biomarkers did with overall food consumption. Low-nutrient-density foods may compromise adolescents' vitamin status.

High-throughput method for the quantitation of metabolites and co-factors from homocysteine-methionine cycle for nutritional status assessment

AIM

There is increasing interest in the profiling and quantitation of methionine pathway metabolites for health management research. Currently, several analytical approaches are required to cover metabolites and co-factors.

RESULTS

We report the development and the validation of a method for the simultaneous detection and quantitation of 13 metabolites in red blood cells. The method, validated in a cohort of healthy human volunteers, shows a high level of accuracy and reproducibility.

CONCLUSION

This high-throughput protocol provides a robust coverage of central metabolites and co-factors in one single analysis and in a high-throughput fashion. In large-scale clinical settings, the use of such an approach will significantly advance the field of nutritional research in health and disease.

The Research on the Impact of Maca Polypeptide on Sport Fatigue

In order to study the effect of maca polypeptide on sport fatigue, this paper selected 40 male mice, and they were randomly divided into group A, B, C and D. group A, B and C were fed food with different concentrations of maca polypeptide, and group D was control group. After two weeks of feeding, measured physiological indexes of mice, including blood glucose, urea nitrogen and creatinine. At last gived the experimental results, as well as the analysis. Experimental results show that maca polypeptide can improve the ability of anti-fatigue mice, and in a certain concentration range, the higher the concentration, the better the resistance to fatigue.

Proteomic Analysis of One-carbon Metabolism-related Marker in Liver of Rat Offspring

Maternal food intake has a significant effect on the fetal environment, and an inadequate maternal diet may result in intrauterine growth restriction. Intrauterine growth restriction newborn rat pups nursed by normal diet-fed dams exhibited rapid catch-up growth, which plays a critical role in the risk for metabolic and cardiovascular disease in later life. Specifically, one-carbon metabolism in the liver plays a critical role in placental and fetal growth. Impaired functioning of one-carbon metabolism is associated with increased homocysteine levels. In this study, we applied a comprehensive proteomic approach to identify differential expression of proteins related to one-carbon metabolism in the livers of rat offspring as an effect of maternal food restriction during gestation. Data are available via ProteomeXchange with identifier PXD002578. We determined that betaine-homocysteine S-methyltransferase 1, methylenetetrahydrofolate dehydrogenase 1, and ATP synthase subunit beta mitochondrial (ATP5B) expression levels were significantly reduced in the livers of rat offspring exposed to maternal food restriction during gestation compared with in the offspring of rats fed a normal diet (p < 0.05). Moreover, the expression levels of betaine-homocysteine S-methyltransferase 1, methylenetetrahydrofolate dehydrogenase 1, and ATP synthase subunit beta mitochondrial were negatively correlated with serum homocysteine concentration in male offspring exposed to maternal food restriction during gestation and normal diet during lactation. However, in female offspring only expression levels of methylenetetrahydrofolate dehydrogenase 1 were negatively correlated with homocysteine concentration. This study shows that maternal food restriction during late gestation and normal diet during lactation lead to increased homocysteine concentration through disturbance of one-carbon metabolism in the livers of male offspring. This suggests that male offspring have an increased gender-specific susceptibility to disease in later life through fetal programming.

Biomarkers of Nutrition for Development-Folate Review

The Biomarkers of Nutrition for Development (BOND) project is designed to provide evidence-based advice to anyone with an interest in the role of nutrition in health. Specifically, the BOND program provides state-of-the-art information and service with regard to selection, use, and interpretation of biomarkers of nutrient exposure, status, function, and effect. To accomplish this objective, expert panels are recruited to evaluate the literature and to draft comprehensive reports on the current state of the art with regard to specific nutrient biology and available biomarkers for assessing nutrients in body tissues at the individual and population level. Phase I of the BOND project includes the evaluation of biomarkers for 6 nutrients: iodine, iron, zinc, folate, vitamin A, and vitamin B-12. This review represents the second in the series of reviews and covers all relevant aspects of folate biology and biomarkers. The article is organized to provide the reader with a full appreciation of folate's history as a public health issue, its biology, and an overview of available biomarkers (serum folate, RBC folate, and plasma homocysteine concentrations) and their interpretation across a range of clinical and population-based uses. The article also includes a list of priority research needs for advancing the area of folate biomarkers related to nutritional health status and development.

Folate Status and Intake of Tribal Indian Adolescents Aged 10 to 17 Years

Background

Adequate folate intake and levels are advisable throughout life but are of particular importance during adolescence, a period of rapid growth. However, folate insufficiency in economically deprived Indian adolescents is understudied.

Objective

This cross-sectional study examined the prevalence of folate deficiency and adequacy of folate intake of 224 tribal Indian adolescents (10 to 17 years of age). The secondary aim was to study the association between anemia status and folate status.

Methods

Radioimmunoassay, multiple-pass 24-hour dietary recall, and HemoCue were used to measure red blood cell (RBC) folate, folate intake, and anemia status, respectively.

Results

The geometric mean (95% CI) RBC folate concentration (nmol/L) was 360.2 (329.7 to 393.6), and the mean ± SD folate intake (μg/day) and hemoglobin level (g/L) were 159.9 ± 44.7 and 125.4 ± 13.0, respectively. Almost half of boys and girls aged 10 to 12 and 13 to 15 years and 66.7% of girls aged 16 to 17 years were deficient in RBC folate (< 340 nmol/L). The mean ± SD folate intake (μg/day) of girls (139.4 ± 34.5) was lower than that of boys (173.8 ± 45.5) ( p < .001). With respect to adequacy of folate intake, a greater proportion of girls in the age group of 13–15 years (78.5% vs 38.6%, p < 0.001) and 16–17 years (100.0% vs 76.9%, p = 0.04) had intakes below their Recommended Dietary Allowance (RDA). No association was observed between folate intake and RBC folate deficiency or between anemia status and RBC folate deficiency.

Conclusions

Folate insufficiency was widespread in tribal Indian adolescents. There is an urgent need to develop culturally sensitive strategies for improvement.

Simultaneous determination of ascorbic acid, aminothiols, and methionine in biological matrices using ion-pairing RP-HPLC coupled with electrochemical detector

A novel highly sensitive ion-pairing reversed-phase high performance liquid-chromatography/electrochemical detection method for simultaneous determination of L -ascorbic acid, aminothiols, and methionine in biological matrices is presented. Reduced forms of the analytes are extracted from sample matrices with 10% m-phosphoric acid solution(aqueous). To determine the total vitamin C, the total aminothiols, and the total methionine, samples are treated with tris(2-carboxyethyl)phosphine solution in 0.05% trifluoroacetic acid solution(aqueous) subsequent to deproteination to reduce the oxidized forms of these compounds. Various analytes are separated on a C18 (250 × 4.6 mm, 5 μm) analytical column using methanol-0.05% trifluoroacetic acid solution(aqueous) (05:95 v/v, containing 0.1 mM 1-octane sulfonic acid as the ion-pairing agent) as the isocratic mobile phase that is pumped at a flow rate of 1.5 ml/min at room temperature. The column eluents are monitored at a voltage of 0.85 V. These analytes are efficiently resolved in less than 20 min using n-acetyl cysteine as the internal standard.

Nutrition and lifestyle in european adolescents: the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study

Adolescence is a critical period, because major physical and psychologic changes occur during a very short period of time. Changes in dietary habits may induce different types of nutritional disorders and are likely to track into adulthood. The aim of this review is to describe the key findings related to nutritional status in European adolescents participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study. We performed a cross-sectional study in 3528 (1845 females) adolescents aged 12.5–17.5 y. Birth weight was negatively associated with abdominal fat mass in adolescents and serum leptin concentrations (in female adolescents), providing additional evidence for a programming effect of birth weight on energy homeostasis control. Breakfast consumption was associated with lower body fat content and healthier cardiovascular profile. Adolescents eat half of the recommended amount of fruit and vegetables and less than two-thirds of the recommended amount of milk and milk products but consume more meat and meat products, fats, and sweets than recommended. For beverage consumption, sugar-sweetened beverages, sweetened milk, low-fat milk, and fruit juice provided the highest amount of energy. Although the intakes of saturated fatty acids (FAs) and salt were high, the intake of polyunsaturated FAs was low. Adolescents spent, on average, 9 h/d of their waking time (66–71% and 70–73% of the registered time in boys and girls, respectively) in sedentary activities. Factors associated with adolescents’ sedentary behavior included the following: 1) age; 2) media availability in the bedroom; 3) sleeping time; 4) breakfast consumption; and 5) season. Sedentary time was also associated with cardiovascular risk factors and bone mineral content. In European adolescents, deficient concentrations were identified for plasma folate (15%), vitamin D (15%), pyridoxal 5′-phosphate (5%), β-carotene (25%), and vitamin E (5%). Scientists and public health authorities should raise awareness of the importance of a healthy and sustainable lifestyle as a foundation of the health of the European population, now and in the future.

Micronutrient deficiencies are common in 6- to 8-year-old children of rural Nepal, with prevalence estimates modestly affected by inflammation

Subclinical micronutrient deficiencies remain a hidden aspect of malnutrition for which comprehensive data are lacking in school-aged children. We assessed the micronutrient status of Nepalese children, aged 6 to 8 y, born to mothers who participated in a community-based antenatal micronutrient supplementation trial from 1999 to 2001. Of 3305 participants, plasma indicators were assessed in a random sample of 1000 children. Results revealed deficiencies of vitamins A (retinol <0.70 μmol/L, 8.5%), D (25-hydroxyvitamin D <50 nmol/L, 17.2%), E (α-tocopherol <9.3 μmol/L, 17.9%), K (decarboxy prothombin >2 μg/L, 20%), B-12 (cobalamin <150 pmol/L, 18.1%), B-6 [pyridoxal-5'-phosphate (PLP) <20 nmol/L, 43.1%], and β-carotene (41.5% <0.09 μmol/L), with little folate deficiency (6.2% <13.6 nmol/L). Deficiencies of iron [ferritin <15 μg/L, 10.7%; transferrin receptor (TfR) >8.3 mg/L, 40.1%; TfR:ferritin >500 μg/μg, 14.3%], iodine (thyroglobulin >40 μg/L, 11.4%), and selenium (plasma selenium <0.89 μmol/L, 59.0%) were observed, whereas copper deficiency was nearly absent (plasma copper <11.8 μmol/L, 0.7%). Hemoglobin was not assessed. Among all children, 91.7% experienced at least 1 micronutrient deficiency, and 64.7% experienced multiple deficiencies. Inflammation (α-1 acid glycoprotein >1 g/L, C-reactive protein >5 mg/L, or both) was present in 31.6% of children, affecting the prevalence of deficiency as assessed by retinol, β-carotene, PLP, ferritin, TfR, selenium, copper, or having any or multiple deficiencies. For any nutrient, population deficiency prevalence estimates were altered by ≤5.4% by the presence of inflammation, suggesting that the majority of deficiencies exist regardless of inflammation. Multiple micronutrient deficiencies coexist in school-aged children in rural Nepal, meriting more comprehensive strategies for their assessment and prevention.

Socioeconomic factors are associated with folate and vitamin B12 intakes and related biomarkers concentrations in European adolescents: the Healthy Lifestyle in Europe by Nutrition in Adolescence study

Because socioeconomic factors (SEFs) may influence dietary quality and vitamin intakes, this study aimed to examine associations between socioeconomic factors and folate and vitamin B12 intakes as well as their related biomarkers in the Healthy Lifestyle in Europe by Nutrition in Adolescence study. Vitamin intakes were obtained from two 24-hour recalls in 2253 participants (47% males). Vitamin B biomarkers were assessed in a subsample of 977 participants (46% males). Socioeconomic factors were assessed by questionnaire, and 1-way analysis of covariance and linear regression analysis were applied. For males and females, mean intakes of folate were 211.19 and 177.18 μg/d, and for vitamin B12, 5.98 and 4.54 μg/d, respectively. Levels of plasma folate, red blood cell folate, serum B12, and holotranscobalamin were 18.74, 807.19, 330.64, and 63.04 nmol/L in males, respectively, and 19.13, 770.16, 377.9, and 65.63 nmol/L in females, respectively. Lower folate intakes were associated with several SEFs, including maternal and paternal education in both sexes. Regarding folate biomarkers, lower plasma folate intakes were associated with single/shared care in males and with lower paternal occupation in females. Lower vitamin B12 intakes were associated with almost all the studied SEFs, except paternal occupation in both sexes. In females, when considering vitamin B12 biomarkers, lower plasma vitamin B12 was associated with lower maternal education and occupation, and lower holotranscobalamin was associated with lower maternal education and lower paternal occupation. In conclusion, from the set of socioeconomic determinants studied in a sample of European adolescents, maternal education and paternal occupation were more consistently associated with folate and vitamin B12 intakes and biomarkers concentrations.

Three-month B vitamin supplementation in pre-school children affects folate status and homocysteine, but not cognitive performance

BACKGROUND

Suboptimal vitamin B status might affect cognitive performance in early childhood. We tested the hypothesis that short-term supplementation with folic acid and selected B vitamins improves cognitive function in healthy children in a population with relatively low folate status.

METHODS

We screened 1,002 kindergarten children for suboptimal folate status by assessing the total urinary para-aminobenzoylglutamate excretion. Two hundred and fifty low ranking subjects were recruited into a double blind, randomized, controlled trial to receive daily a sachet containing 220 μg folic acid, 1.1 mg vitamin B2, 0.73 mg B6, 1.2 μg B12 and 130 mg calcium, or calcium only for 3 months. Primary outcomes were changes in verbal IQ, short-term memory and processing speed between baseline and study end. Secondary outcomes were urinary markers of folate and vitamin B12 status, acetyl-para-aminobenzoylglutamate and methylmalonic acid, respectively, and, in a subgroup of 120 participants, blood folate and plasma homocysteine.

RESULTS

Pre- and post-intervention cognitive measurements were completed by 115 children in the intervention and 122 in the control group. Compared to control, median blood folate increased by about 50% (P for difference, P < 0.0001). Homocysteine decreased by 1.1 μmol/L compared to baseline, no change was seen in the control group (P for difference P < 0.0001) and acetyl-para-aminobenzoylglutamate was 4 nmol/mmol higher compared to control at the end of the intervention (P < 0.0001). We found no relevant differences between the groups for the cognitive measures.

CONCLUSION

Short-term improvement of folate and homocysteine status in healthy children does not appear to affect cognitive performance.

Effect of a plant sterol, fish oil and B vitamin combination on cardiovascular risk factors in hypercholesterolemic children and adolescents: a pilot study

BACKGROUND

Assessment of cardiovascular disease (CVD) risk factors can predict clinical manifestations of atherosclerosis in adulthood. In this pilot study with hypercholesterolemic children and adolescents, we investigated the effects of a combination of plant sterols, fish oil and B vitamins on the levels of four independent risk factors for CVD; LDL-cholesterol, triacylglycerols, C-reactive protein and homocysteine.

METHODS

Twenty five participants (mean age 16 y, BMI 23 kg/m2) received daily for a period of 16 weeks an emulsified preparation comprising plant sterols esters (1300 mg), fish oil (providing 1000 mg eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA)) and vitamins B12 (50 μg), B6 (2.5 mg), folic acid (800 μg) and coenzyme Q10 (3 mg). Atherogenic and inflammatory risk factors, plasma lipophilic vitamins, provitamins and fatty acids were measured at baseline, week 8 and 16.

RESULTS

The serum total cholesterol, LDL- cholesterol, VLDL-cholesterol, subfractions LDL-2, IDL-1, IDL-2 and plasma homocysteine levels were significantly reduced at the end of the intervention period (p<0.05). The triacylglycerols levels decreased by 17.6%, but did not reach significance. No significant changes in high sensitivity C-reactive protein, HDL-cholesterol and apolipoprotein A-1 were observed during the study period. After standardisation for LDL cholesterol, there were no significant changes in the levels of plasma γ-tocopherol, β-carotene and retinol, except for reduction in α-tocopherol levels. The plasma levels of n-3 fatty acids increased significantly with the dietary supplementation (p<0.05).

CONCLUSIONS

Daily intake of a combination of plant sterols, fish oil and B vitamins may modulate the lipid profile of hypercholesterolemic children and adolescents.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN89549017.

Folate, vitamin B₁₂ and total homocysteine levels in Arab adolescent subjects: reference ranges and potential determinants

BACKGROUND & AIMS

Elevated circulating fasting total homocysteine (tHcy) concentration is associated with an increased risk of occlusive vascular disease in adults. Important determinants of tHcy levels are folate, vitamin B(12) and vitamin B(6). This study aimed to investigate age, gender, and body mass as determinants of folate, vitamin B(12) and tHcy levels in Arab older children and adolescents and to propose population, gender and age-specific reference ranges for these biomarkers.

METHODS & RESULTS

774 (316 boys, 458 girls) healthy 10-19 yr olds attending secondary schools in Kuwait were assessed for anthropometry and fasting blood levels of Hcy, folate and vitamin B(12). The mean (95% CI) serum levels of tHcy, folate and vitamin B(12) were respectively 6.57 μmol/L (6.42-6.73), 16.0 ng/ml (15.6-16.3) and 354.3 pg/ml (343.0-365.7). Boys had significantly higher tHcy and folate concentrations than the girls, although vitamin B(12) levels were greater in the latter. Folate and vitamin B(12) levels decreased significantly with age, while correspondingly, tHcy levels increased, with mean values (μmol/L) for boys (6.71; 8.25) and girls (5.36; 6.67) aged 10-14 yr and 14-19 yr respectively. Bivariate and multivariate analyses with adjustment for confounders such as age, gender, need for dietary control and socio-demographic variables indicated that the independent determinants of levels of tHcy were age, gender and body mass.

CONCLUSION

There is an age-related increase in tHcy in adolescents reflecting decreased levels of folate and vitamin B(12), with the suggestion that age-related reference ranges for these biomarkers be used. These observations may have implications for prevention of future atherogenic disease.

The association of cysteine with obesity, inflammatory cytokines and insulin resistance in Hispanic children and adolescents

Context

Plasma total cysteine (tCys) independently relates to fat mass in adults. Dietary cyst(e)ine promotes adiposity and decreases glucose tolerance in some rodent models, but alleviates insulin resistance in others.

Objective

To investigate whether the association of tCys with body fat extends to children at particular risk of obesity, and whether tCys is associated with insulin resistance and obesity-associated inflammation.

Methods

We explored the cross-sectional relations of fasting plasma tCys and related metabolites with body composition measured by dual-energy X-ray absorptiometry in 984 Hispanic children and adolescents aged 4–19 years from the Viva La Familia Study. Linear and logistic regression and dose-response curves were used to evaluate relations of tCys with obesity, insulin resistance and inflammatory markers including interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1) and C-reactive protein (CRP).

Results

tCys, methionine and total homocysteine (tHcy) increased with age. Upper tCys quartile was independently associated with a 5-fold increased risk of obesity (95% CI 3.5–8.0, P<0.001), and 2-fold risk of insulin resistance (95% CI: 1.6-5.0, P<0.001; adjusted for body fat%). Within the overweight/obese subgroup, but not in normal-weight children, tCys accounted for 9% of the variability in body fat% (partial r = 0.30, P<0.001; adjusted for age and gender). tCys correlated positively with serum non-esterified fatty acids and leptin, partly independent of body fat, but was not associated with serum IL-6, TNF-α or MCP-1. A positive correlation with CRP disappeared after adjustment for BMI.

Conclusion

tCys is independently associated with obesity and insulin resistance in Hispanic children and adolescents, highlighting a previously underappreciated link between the sulfur amino acid metabolic pathway and obesity and cardiometabolic risk.

Methylation capacity in children with severe cerebral palsy

BACKGROUND

  Methylation cycle and folate-mediated one-carbon metabolism maintenance is important for many physiological processes including neurotransmitter regulation, nerve myelination and DNA synthesis. These processes play an indispensible role in growth and development, as well as in cognitive function and neuromuscular stability, which are key issues in children with severe cerebral palsy (CP).

METHODS

  Blood samples were collected from children with severe CP (n = 24) and age-matched typically developing healthy controls (n = 24), as an exploratory study. The CP group was divided into orally (O) or enterally fed via percutaneous endoscopic gastrostomy (E). Concentrations of red cell folate (RCF), methylmalonic acid (MMA), mean cell volume (MCV), homocysteine (Hcy), cystathionine, choline, betaine and urate were assayed.

RESULTS

  Homocysteine was increased in both O mean (±SD) = 6·28 (±1·81 μM) and E = 6·03 (±1·28), vs. controls = 5·07 (±0·98) P = 0·02. Higher MMA was found in controls = 157 (±54) and O = 141 (±101), vs. E = 88(±21) P = 0·05. RCF was higher in E = 1422 (±70 nM) vs. O = 843 (±80) and controls = 820 (±43) P < 0·001. MCV z-scores were elevated in E = 3·1 (±1·8) and O = 1·1 (±1·1) compared with controls = -0·2 (±1·1) P < 0·001. Urate was significantly reduced in O = -0·64 (±1·38) and E = -0·87 (±0·71), vs. controls = 0·18 (±0·62) P = 0·006.

CONCLUSIONS

  Raised MCV in the presence of elevated red cell folate, adequate B12 status and low plasma urate suggest potential methyltetrahydrofolate trapping and impaired purine synthesis. Well-documented malnutrition issues in O may explain differences between CP groups. These data support the hypothesis of possible dysregulation in methylation capacity and/or folate one-carbon metabolism, although more research is needed to elucidate a precise mechanism.

Development of biomarkers to optimize pediatric patient management: what makes children different?

Despite the frequent utilization of biomarkers in medical practice, there is a relative paucity of information regarding validated pediatric biomarkers. Frequently, biomarkers found to be efficacious in adults are extrapolated to the pediatric clinical setting without considering that the pathogenesis of many diseases is distinctly different in children, and ontogeny directly influences disease evolution and therapeutic response in children. New and innovative approaches are necessary to provide reliable, validated biomarkers that can be used to improve and advance pediatric medical care.

Polymorphisms in 1-carbon metabolism, epigenetics and folate-related pathologies

Folate-mediated 1-carbon metabolism is a network of interconnected metabolic pathways necessary for the synthesis of purine nucleotides, thymidylate and the remethylation of homocysteine to methionine. Disruptions in this pathway influence both DNA synthesis and stability and chromatin methylation, and result from nutritional deficiencies and common gene variants. The mechanisms underlying folate-associated pathologies and developmental anomalies have yet to be established. This review focuses on the relationships among folate-mediated 1-carbon metabolism, chromatin methylation and human disease, and the role of gene-nutrient interactions in modifying epigenetic processes.

Novel risk factors of cardiovascular disease and their associations between obesity, physical activity and physical fitness

The prevalence of cardiovascular disease (CVD) is increasing around the globe and is the leading cause of death around the world. Though once thought of as an adult problem, it is now recognised that the early manifestations of disease may occur during childhood. Numerous risk factors have been linked to CVD with much of the research focusing on understanding the prevalence and relationship of traditional risk factors such as dyslipidemia, smoking, diabetes mellitus, hypertension, obesity, psychosocial stress, poor diet, physical inactivity and alcohol consumption to the early etiology of disease. While this line of investigation has greatly enhanced our understanding of the relationship between these risk factors and disease, they do not fully explain all cardiovascular events. To enhance our understanding and help with the management of CVD, investigations that involve the measurement of traditional as well as novel risk factors may be necessary. Public health strategies that aim to reduce the prevalence of obesity and overweight encourage youth to increase their physical activity levels as a means of protecting against poor cardiometabolic profiles. Interventions that increase physical activity levels and improve cardiorespiratory fitness cause a reduction in certain CVD risk factors but the lack of agreement between findings makes it impossible to give precise recommendations that will ensure CVD risk reduction. Yet it is important that research continues in order to establish the most appropriate means of improving the health and well-being of those at most risk of future CVD.

Total blood mercury, plasma homocysteine, methylmalonic acid and folate in US children aged 3-5 years, NHANES 1999-2004

BACKGROUND

Mercury is a known neurotoxicant; however, the relationship between childhood exposures and neurodevelopmental outcomes is uncertain, and may be modified by nutrition-related susceptibilities. In vitro studies found that mercury inhibited methionine synthase, an enzyme that interacts with vitamin B-12 and folate to regenerate the amino acid methionine from homocysteine, and inhibition of methionine synthase diverted homocysteine to cysteine and glutathione synthesis. The relationships between mercury, homocysteine, B-12, and folate have not been examined in children.

OBJECTIVE

This study aimed to evaluate associations between Hg and homocysteine in male and female children differentiated by higher and lower methylmalonic acid (MMA, an indicator of vitamin B-12 deficiency) and folate status.

DESIGN

Cross-sectional data on total blood mercury (Hg), plasma homocysteine, MMA, and serum folate were obtained from the 1999-2004 National Health and Nutrition Examination Surveys for children aged 3-5 years (n=1005). We used multiple linear regression to evaluate relationships between homocysteine and Hg quartiles, stratified by sex, MMA ≥ and folate < sample medians, adjusted for demographic, anthropometric, and environmental factors.

RESULTS

In boys with higher MMA and lower folate (n=135), but not in other children, we observed inverse associations between homocysteine and Hg. Children with Hg >3.49 μmol/L showed 1.14 μmol/L lower homocysteine (p<0.001) relative to the lowest quartile (≤ 0.70 μmol/L) {p-value for trend<0.001}. Compared to other subsamples, this subsample had significantly higher homocysteine levels.

CONCLUSION

Hg was inversely correlated with plasma homocysteine in young boys, but not girls, with higher MMA and lower folate. Additional studies are merited to evaluate Hg and amino acid metabolism in susceptible children.

Folate metabolism pathway and Plasmodium falciparum malaria infection in pregnancy

Malaria induced by Plasmodium falciparum is a major cause of mortality. P. falciparum has the ability to use host plasma folate as its primary folate source. Folate is a cofactor needed for both malaria parasite growth and host erythrocyte production. This review examines the possible impairment of the folate-mediated one-carbon metabolism pathway as a result of P. falciparum malaria infection during pregnancy. Folate deficiency during malaria infection is presented, with an emphasis on the controversy regarding the decrease of plasma or erythrocyte folate secondary to malaria. Maternal folate deficiency increases the risk of adverse pregnancy outcomes. Functional folate deficiency and/or increased plasma homocysteine levels during pregnancy of infected women in areas endemic for malaria is a probable scenario accentuating the impairment of placenta function leading to the occurrence of neural tube defects, low birth weights, and intrauterine growth retardations. Potential questions that may be answered in future investigations using an appropriate protocol to study pregnant women with malaria are also addressed.

Nutrient contribution of total and lean beef in diets of US children and adolescents: National Health and Nutrition Examination Survey 1999-2004

This study examined the nutritional contribution of total beef and lean beef (LB) to the diet of US children and adolescents using the US Department of Agriculture definition of LB as defined in MyPyramid. Twenty-four hour dietary recall data from children 4-8 years of age [y] (n=2474), 9-13 y (n=3273), and adolescents 14-18 y (n=4044) participating in the NHANES 1999-2004 were assessed. LB was defined as beef with ≤9.28 grams [g] fat/100 g (excess was discretionary fat). Means and standard errors were determined using appropriate sample weights. Consumption of LB contributed significantly to intake of protein and many key nutrients such as vitamins B6 and B12, zinc, iron, niacin, phosphorus, and potassium by US children and adolescents without providing significantly to intakes of total fat, saturated fatty acids, or sodium.

Vitamin B12 and older adults

PURPOSE OF REVIEW

To review the prevalence, causes and functional significance of vitamin B12 deficiency in vulnerable subpopulations including older adults and the developing embryo.

RECENT FINDINGS

It is becoming increasingly recognized that the susceptibility to vitamin B12 deficiency may change throughout the life cycle, with the developing embryo and older adults exhibiting elevated risk. Recent data implicate low vitamin B12 status as a risk factor for birth defects resulting from improper neural tube development. The potential for vitamin supplementation and/or food fortification to ameliorate the risk of deficiency in these subpopulations is discussed.

SUMMARY

The prevalence and impact of vitamin B12 deficiency varies throughout the life cycle, with older adults and potentially the developing embryo having the greatest risk and susceptibility. Additional research is needed to develop effective public health interventions that address the unique causes of this nutritional deficiency, which differ among at-risk subpopulations.