Quantification of urinary folate catabolites using liquid chromatography-tandem mass spectrometry

Infants' Folate Markers and Postnatal Growth in the First 4 Months of Life in Relation to Breastmilk and Maternal Plasma Folate

BACKGROUND

Human milk is the sole source of folate in exclusively breastfed infants. We investigated whether human milk folate or maternal plasma folate are associated with infants' folate status and postnatal growth in the first 4 months of life.

METHODS

Exclusively breastfed infants (n = 120) were recruited at age < 1 month (baseline). Blood samples were available at baseline and at the age of 4 months. Plasma and breastmilk samples were available from the mothers at 8 weeks postpartum. The concentrations of (6S)-5-methyltetrahydrofolate (5-MTHF) and different folate status markers were measured in samples of the infants and their mothers. The z-scores of weight, height, and head circumference of the infants were measured five times between baseline and 4 months.

RESULTS

Women with 5-MTHF concentrations in breastmilk <39.9 nmol/L (median) had higher plasma 5-MTHF compared to those with milk 5-MTHF concentrations >39.9 nmol/L (mean (SD) plasma 5-MTHF = 23.3 (16.5) vs. 16.6 (11.9) nmol/L; p = 0.015). At the age of 4 months, infants of women who were higher suppliers of 5-MTHF in breastmilk had higher plasma folate than those of low-supplier women (39.2 (16.1) vs. 37.4 (22.4) nmol/L; adjusted p = 0.049). The concentrations of breastmilk 5-MTHF and maternal plasma folate were not associated with infants' longitudinal anthropometric measurements between baseline and 4 months.

CONCLUSIONS

Higher 5-MTHF in breastmilk was associated with higher folate status in the infants and the depletion of folate in maternal circulation. No associations were seen between maternal or breastmilk folate and infants' anthropometrics. Adaptive mechanisms might counteract the effect of low milk folate on infant development.

Infant blood concentrations of folate markers and catabolites are modified by 5,10-methylenetetrahydrofolate reductase C677T genotype and dietary folate source

BACKGROUND

Folate intake and polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene may affect folate metabolism in infants.

OBJECTIVES

We investigated the association between infant's MTHFR C677T genotype, the dietary folate source, and concentrations of folate markers in the blood.

METHODS

We studied 110 breastfed infants (reference) and 182 infants who were randomly assigned to receive infant formulas enriched with either 78 μg folic acid or 81 μg (6S)-5-methyltetrahydrofolate (5-MTHF) per 100 g milk powder for 12 wk. The blood samples were available at the ages of <1 mo (baseline) and 16 wk. MTHFR genotype and concentrations of folate markers and catabolites [i.e., para-aminobenzoylglutamate (pABG)] were analyzed.

RESULTS

At baseline, carriers of the TT genotype (vs. CC) had lower mean (SD) concentrations (all in nmol/L) of red blood cell (RBC) folate [1194 (507) vs. 1440 (521), P = 0.033) and plasma pABG [5.7 (4.9) vs. 12.5 (8.1), P < 0.001] but higher plasma 5-MTHF [33.9 (16.8) vs. 24.0 (12.6), P < 0.001]. Irrespective of the genotype, infant formula with 5-MTHF (vs. folic acid) caused a significant increase in RBC folate concentration [1278 (466) vs. 947 (552), P < 0.001]. In breastfed infants, plasma concentrations of 5-MTHF and pABG increased significantly by 7.7 (20.5) and 6.4 (10.5), respectively, from baseline to 16 wk. Infant formula that complies with the present EU legislation for folate intake increased RBC folate and plasma pABG concentrations at 16 wk (P < 0.001) than formula-fed infants. At 16 wk, plasma pABG concentrations remained ∼50% lower in carriers of the TT (vs. the CC) genotype among all feeding groups.

CONCLUSIONS

Folate intake from infant formula according to the present EU legislation increased RBC folate and plasma pABG concentrations in infants to a greater extent than breastfeeding, particularly in carriers of the TT genotype. However, this intake did not completely abolish the between-genotype differences in pABG. Whether these differences have any clinical relevance, however, remains unclear. This trial was registered at clinicaltrials.gov as NCT02437721.

An LC-MS chemical derivatization method for the measurement of five different one-carbon states of cellular tetrahydrofolate

The cofactor tetrahydrofolate (THF) is used to reduce, oxidize, and transfer one-carbon (1C) units required for the synthesis of nucleotides, glycine, and methionine. Measurement of intracellular THF species is complicated by their chemical instability, signal dilution caused by variable polyglutamation, and the potential for interconversion among these species. Here, we describe a method using negative mode liquid chromatography-mass spectrometry (LC-MS) to measure intracellular folate species from mammalian cells. Application of this method with isotope-labeled substrates revealed abiotic interconversion of THF and methylene-THF, which renders their separate quantitation particularly challenging. Chemical reduction of methylene-THF using deuterated sodium cyanoborohydride traps methylene-THF, which is unstable, as deuterated 5-methyl-THF, which is stable. Together with proper sample handling and LC-MS, this enables effective measurements of five active folate pools (THF, 5-methyl-THF, methylene-THF, methenyl-THF/10-formyl-THF, and 5-formyl-THF) representing the biologically important 1C oxidation states of THF in mammalian cells. Graphical abstract Chemical derivatization with deuterated cyanoborohydride traps unstable methylene-THF as isotope-labeled 5-methyl-THF, enabling accurate quantification by LC-MS.

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.

Regulation of early human growth: impact on long-term health

Growth and development are central characteristics of childhood. Deviations from normal growth can indicate serious health challenges. The adverse impact of early growth faltering and malnutrition on later health has long been known. In contrast, the impact of rapid early weight and body fat gain on programming of later disease risk have only recently received increased attention. Numerous observational studies related diet in early childhood and rapid early growth to the risk of later obesity and associated disorders. Causality was confirmed in a large, double-blind randomised trial testing the 'Early Protein Hypothesis'. In this trial we found that attenuation of protein supply in infancy normalized early growth and markedly reduced obesity prevalence in early school age. These results indicate the need to describe and analyse growth patterns and their regulation through diet in more detail and to characterize the underlying metabolic and epigenetic mechanisms, given the potential major relevance for public health and policy. Better understanding of growth patterns and their regulation could have major benefits for the promotion of public health, consumer-orientated nutrition recommendations, and the development of improved food products for specific target populations.

The Power of Programming and the EarlyNutrition project: opportunities for health promotion by nutrition during the first thousand days of life and beyond

At The Power of Programming 2014 Conference, researchers from multiple disciplines presented and discussed the effects of early nutrition and other environmental cues during the first thousand days of life and beyond on the lifelong risk of noncommunicable diseases. This paper aims to summarize the concepts and some of the first achievements of the EarlyNutrition research project that initiated the conference. The EarlyNutrition consortium is a multinational, multidisciplinary research collaboration of researchers from Europe, the USA, and Australia. A focus is placed on exploration of the developmental origins of obesity, adiposity, and related health outcomes. Here we report on the first findings of experimental approaches, cohort studies, randomized clinical trials, and systematic reviews of current information, as well as position papers, which have all been developed with the involvement of project partners. We conclude that the EarlyNutrition project has successfully established itself during the first 2 project years as a very strong platform for collaborative research on early programming effects. The first results, available already at this early stage of the project, point to great opportunities for health prevention strategies via the implementation of dietary and lifestyle modifications, with large effect sizes. Further results are expected which should support improved recommendations and related policies for optimized nutrition and lifestyle choices before and during pregnancy, in infancy, and in early childhood.

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.