Dietary intake and food sources of one-carbon metabolism nutrients in preschool aged children

Metabolomic Effects of Folic Acid Supplementation in Adults: Evidence from the FACT Trial

BACKGROUND

Folic acid (FA) is the oxidized form of folate found in supplements and FA-fortified foods. Most FA is reduced by dihydrofolate reductase to 5-methyltetrahydrofolate (5mTHF); the latter is the form of folate naturally found in foods. Ingestion of FA increases the plasma levels of both 5mTHF and unmetabolized FA (UMFA). Limited information is available on the downstream metabolic effects of FA supplementation, including potential effects associated with UMFA.

OBJECTIVE

We aimed to assess the metabolic effects of FA-supplementation, and the associations of plasma 5mTHF and UMFA with the metabolome in FA-naïve Bangladeshi adults.

METHODS

Sixty participants were selected from the Folic Acid and Creatine Trial; half received 800 μg FA/day for 12 weeks and half placebo. Plasma metabolome profiles were measured by high-resolution mass spectrometry, including 170 identified metabolites and 26,541 metabolic features. Penalized regression methods were used to assess the associations of targeted metabolites with FA-supplementation, plasma 5mTHF, and plasma UMFA. Pathway analyses were conducted using Mummichog.

RESULTS

In penalized models of identified metabolites, FA-supplementation was associated with higher choline. Changes in 5mTHF concentrations were positively associated with metabolites involved in amino acid metabolism (5-hydroxyindoleacetic acid, acetylmethionine, creatinine, guanidinoacetate, hydroxyproline/n-acetylalanine) and 2 fatty acids (docosahexaenoic acid and linoleic acid). Changes in 5mTHF concentrations were negatively associated with acetylglutamate, acetyllysine, carnitine, propionyl carnitine, cinnamic acid, homogentisate, arachidonic acid, and nicotine. UMFA concentrations were associated with lower levels of arachidonic acid. Together, metabolites selected across all models were related to lipids, aromatic amino acid metabolism, and the urea cycle. Analyses of nontargeted metabolic features identified additional pathways associated with FA supplementation.

CONCLUSION

In addition to the recapitulation of several expected metabolic changes associated with 5mTHF, we observed additional metabolites/pathways associated with FA-supplementation and UMFA. Further studies are needed to confirm these associations and assess their potential implications for human health.

TRIAL REGISTRATION NUMBER

This trial was registered at https://clinicaltrials.gov as NCT01050556.

Dietary intake, nutritional adequacy and food sources of vitamins involved in the methionine-methylation cycle from Spanish children aged one to <10 years: results from the EsNuPI study

Background

Methionine-methylation cycle and the derived critical functions during infancy are key regulated by folates, vitamins B12, and B6. At present in Spain, there is an absence of studies that assess the intakes and dietary sources of total folates and B12 by children consuming all types of milks and those regularly consuming adapted milk formulas. Thus, our aim was to evaluate folates intakes alongside with vitamins B6 and B12 while describing their major dietary contributors in Spanish children aged one to <10 years.

Methods

A total of 1,448 children aged between 1 and 10 years (49.7% girls and 50.3% boys) from the EsNuPI, a prospective cross-sectional study, were allocated into two cohorts: one Spanish Reference Cohort (SRS) of the general population (n = 707), and another including children consuming adapted milks called Adapted Milk Consumers Cohort (AMS) (n = 741) completed two 24 h dietary recalls used to estimate their nutrient intakes and to compare them to the European Food Safety Authority (EFSA) Population Reference Intakes.

Results

The median intake of vitamin B6 was 1.35 (1.06-1.70) mg/day in the SRS and 1.45 (1.17-1.79) mg/day in the AMS, being significantly higher in the AMS for all age-groups. Prevalence of adequacy for vitamin B6 in the SRS and AMS was 97.7 and 98.7%, respectively. Total folates intakes in the AMS were significantly higher (p ≤ 0.001) in all age groups than in the SRS, independently of age. In addition, the prevalence of adequacy for folates intakes in all groups was more than 60%. Vitamin B12 intake increased with age independently of the type of milk consumed. The prevalence of adequacy for vitamin B12 was highly compliant by all population groups. The major contributors to vitamin B6 were milk and dairy products being significantly higher in AMS than SRS (p ≤ 0.001). The highest contributors to folates intakes were milk and dairy products, cereals, vegetables, and fruits in both groups whereas for vitamin B12 in the SRS sample were milk and dairy products followed by meat and meats products and for adapted milks, were milk and dairy products, followed by eggs, then meat and meats products.

Conclusion

A satisfactory prevalence of adequacy for vitamins B6, and B12 amongst the Spanish children population was observed, which was not the case for folates, regardless of the dietary group evaluated. Nevertheless, a possible strategy to increase folate intake among the youngest children is to increase the consumption of milk and dairy products within a healthier dietary pattern, as these may contribute significantly to the vitamin needs of the infant population.

Association between Intake of Total Dairy and Individual Dairy Foods and Markers of Folate, Vitamin B6 and Vitamin B12 Status in the U.S. Population

Vitamin B6, B12 and folate are required for energy metabolism and have been identified as nutrients of concern for certain population groups. This study examined the cross-sectional association between the consumption of dairy (total dairy, milk, yogurt and cheese) and biomarkers and adequacy for these nutrients in a nationally representative sample. Twenty-four-hour dietary recall data and concentrations of RBC folate (ng/mL), serum folate (ng/mL), and serum vitamins B6 (nmol/L) and B12 (pg/mL) were obtained from the National Health and Nutrition Examination Survey 2001−2018 (n = 72,831) and were analyzed by linear and logistic regression after adjusting for demographic variables. Significance was set at p < 0.01. Mean intakes of total dairy were 2.21, 2.17, 1.83 and 1.51 cups eq among consumers aged 2−8, 9−18, 19−50 and 51+ years, respectively. Higher intakes of total dairy as well as individual dairy foods (especially milk and yogurt) were positively associated with serum and RBC folate, serum vitamin B6 and serum B12, and generally, with 9−57% lower risk of inadequate or deficient levels of these vitamins. These findings suggest that encouraging dairy consumption may be an effective strategy for improving micronutrient status and provide continued evidence to support the current dietary recommendations for dairy and dairy products.

Validation of a food-frequency questionnaire to assess methyl-group donor intake in preschoolers

A good assessment of dietary methyl-group donor intake (folate, choline, betaine, methionine) is needed to investigate the effect of methyl-group donor intake on children's health. The aim is to develop and validate a food-frequency questionnaire (FFQ) to estimate the daily intake of methyl-group donors in preschoolers. For the relative validity and reproducibility of the FFQ, a 7-day estimated dietary record (7d EDR) and repeated measurements 6 weeks apart (n = 77) were used respectively. For the validity (n = 75), a moderate ranking ability was obtained (de-attenuated Pearson correlation = 0.43-0.70; weighted ƙ 0.10-0.40), but the FFQ tends to overestimate the real intake. Cross-classification analysis showed that 38% (choline) and 28% (betaine) of the subjects were misclassified. The FFQ shows a moderate to good reproducibility, intra-class correlation coefficients range between 0.67 (betaine) and 0.76 (choline) with a maximal misclassification of 6.5% for betaine (weighted ƙ 0.37-0.69) (n = 77).

CONCLUSION

The FFQ is a tool with a moderate validity and reproducibility to estimate the consumption of dietary methyl-group donors in preschoolers. This tool might be used in future research epidemiological studies including preschoolers.

WHAT IS KNOWN

• Poor dietary habits during childhood have been associated with chronic disease in adulthood. • Methyl-group donors are important for DNA methylation, which is the underlying mechanism of disease development.

WHAT IS NEW

• For the first time, a food-frequency questionnaire that can assess the intake of methione, folate, choline, and betaine has been developed and validated for the use in preschoolers.