# MTHFR 677C/T gene polymorphism and dietary habits: effects on trace element levels, amino acids, and biochemical parameters

**Authors:** Tatjana Orct, Jelena Kovačić, Ines Peremin, Zorana Kljaković-Gašpić, Daria Pašalić, Ankica Sekovanić, Adrijana Dorotić, Blanka Tariba Lovaković, Andreja Jurič, Alica Pizent, Fran Crnjac, Lora Dukić, Marko Gerić, Ivone Jakaša, Goran Gajski

PMC · DOI: 10.3389/fnut.2025.1710613 · Frontiers in Nutrition · 2026-01-12

## TL;DR

This study explores how the MTHFR 677C/T gene variant and meat consumption affect levels of trace elements, amino acids, and biochemical markers in Croatian individuals.

## Contribution

The study reveals novel associations between the MTHFR 677C/T polymorphism, dietary habits, and specific biochemical and elemental levels.

## Key findings

- The CT + TT genotype was linked to lower folate levels compared to the CC genotype.
- The CT + TT genotype showed higher plasma calcium and lower aluminum levels in vegetarians.
- The CT + TT genotype was associated with elevated levels of certain amino acids like glutamic acid and proline.

## Abstract

Previous research has identified that, in individuals with lower folate and/or vitamin B12 levels, homocysteine is associated with specific elements, while amino acids are associated with folate, thereby influencing folate availability during supplementation. This study investigates the impact of the MTHFR 677C/T polymorphism on levels of these compounds in individuals with differing meat consumption preferences, non-vegetarians and vegetarians.

The study was conducted on 162 Croatian subjects. MTHFR gene polymorphism was determined by PCR-RFLP, elements by ICP-QQQ, amino acids by GC–MS, and biochemical parameters by chemiluminescent immunoassay and enzymatic methods. Differences between the groups were tested by ANOVA, while associations between the parameters were examined by multiple regression analyses.

The CT + TT genotype had lower folate levels in comparison to the CC genotype. The influence of MTHFR 677C/T polymorphism on element levels was limited to Al and Ca: individuals with the CT + TT genotype exhibited higher plasma Ca levels than the wild-type (CC) genotype, while lower plasma Al values were observed only in vegetarians with the CT + TT genotype. The CT + TT genotype was also associated with higher levels of glutamic acid, proline, glycine (only in vegetarians), and aspartic acid.

Although we observed an effect of the MTHFR 677C/T polymorphism on folate, certain elements and amino acid levels, further research is required to validate our findings and establish a more comprehensive understanding of the link between elements, amino acids and the MTHFR gene polymorphism.

## Linked entities

- **Genes:** MTHFR (methylenetetrahydrofolate reductase) [NCBI Gene 4524]

## Full-text entities

- **Genes:** MTHFR (methylenetetrahydrofolate reductase) [NCBI Gene 4524]
- **Chemicals:** glycine (MESH:D005998), amino acids (MESH:D000596), Ca (MESH:D002118), glutamic acid (MESH:D018698), vitamin B12 (MESH:D014805), proline (MESH:D011392), folate (MESH:D005492), Al (MESH:D000535), aspartic acid (MESH:D001224), homocysteine (MESH:D006710)
- **Mutations:** 677C/T

## Full text

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## Figures

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## References

151 references — full list in the complete paper: https://tomesphere.com/paper/PMC12832494/full.md

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Source: https://tomesphere.com/paper/PMC12832494