Increase in the prevalence of the MTHFR 677 TT polymorphism in women born since 1959: potential implications for folate requirements

Abstract

Background/Objectives: Folate has been recognized to ensure reproductive health and there is a growing body of epidemiological evidence suggesting that the methylenetetrahydrofolate reductase (MTHFR) 677T allele and reduced dietary folate may increase the risk of cervical cancer. The main focus of our survey was to investigate the distribution of the MTHFR C677T polymorphism in relation to women's year of birth and to assess their folate intake and folic acid supplementation. Subjects/Methods: During a 6-months period, 307 healthy women of childbearing age in Catania, Italy, were enrolled in the cross-sectional study. Folate intake was estimated by a semiquantitative food frequency questionnaire and DNA extracted from blood samples for MTHFR C677T genotyping. Results: A TT genotype frequency of 20.5% with an increase in the prevalence of the TT genotype in the cohort of women born since 1959 was shown. The prevalence of inadequate folate intake was 51.5%, significantly higher in non-pregnant women (83.4%) than in pregnant ones (12.3%) with a decrease during the three trimesters of pregnancy (from 25.7 to 5.0%; P ¼ 0.013). The use of folic acid supplements improved during the three trimester of pregnancy (from 71.4 to 95.0%; P ¼ 0.001).Conclusions: Healthy young women may have higher folate needs due to increasing prevalence of the T allele and reduced folate intake compared with older groups. However, clinicians should be cautious when recommending supplements to women in late pregnancy due to the possible implications in the pregnancy outcome.

Tumor Necrosis Factor-Alpha −308 G>A Polymorphism, Adherence to Mediterranean Diet, and Risk of Overweight/Obesity in Young Women

“…Adherence to MD and FAs intakes, during the past month, was estimated by a semiquantitative 153-item Food Frequencies Questionnaire (FFQ), previously validated [24–26]. For each of the food items, women were asked to report their frequency of consumption and portion size.…”

Dietary Folate Intake and Blood Biomarkers Reveal High-Risk Groups in a Mediterranean Population of Healthy Women of Childbearing Potential

“…The FFQ used in our study was previously validated against a 4-day weighted dietary record [18] and includes alcoholic beverages that are likely to affect folate levels. However, women reported a very low current alcohol intake that contributes minimally to the total folate intake (data not shown).…”

“…Folate intake during the past month was estimated by a validated semiquantitative 46-item food frequency questionnaire (FFQ) using the previous month as a reference period [18]. Previously, the validity of folate intake estimates from the FFQ was assessed in a random subsample of 30 women that completed both the FFQ and, afterwards, a 4-day weighted dietary record, obtaining a Spearman's correlation coefficient of 0.59 [18].…”

“…Previously, the validity of folate intake estimates from the FFQ was assessed in a random subsample of 30 women that completed both the FFQ and, afterwards, a 4-day weighted dietary record, obtaining a Spearman's correlation coefficient of 0.59 [18]. FFQ was administered by trained interviewers.…”

Gene-Environment Interactions and Epigenetic Pathways in Autism: The Importance of One-Carbon Metabolism

“…Certainly, excess folic acid is not always detrimental and may protect embryos with polymorphisms in C 1 -associated genes from spontaneous abortion (Govindaiah et al 2009) and thus alter allelic frequencies in the population. Indeed, an increase in the frequency of the MTHFR 677T allele over a period of 20 years has been suggested (Agodi et al 2011;Munoz-Moran et al 1998). Additionally, early indications suggest that fortifi cation may have shifted the MTHFR 677T allele from a susceptibility to a protective factor for ASDs (Schmidt et al 2011).…”