There is lots of speculation about a connection between folic acid, the MTHFR gene mutation and the increase in infant tongue-tie incidence. This topic comes up frequently in online parenting groups and sometimes in the wider media. The MTHFR gene provides instructions for making an enzyme called methylenetetrahydrofolate reductase. This enzyme is involved in a chemical reaction involving folate. The theory is that a mutation in this gene leads to folate deficiency and people with this mutation cannot process the folic acid recommended preconception and during pregnancy. Folic acid supplementation is recommended to prevent neural tube defects, such as spina bifida. To date there are no published research papers demonstrating a link between folic acid supplementation and tongue-tie. In fact a study by Perez-Aguire et al (2018) which looked at folic acid consumption and a number of oral findings in new-borns found no link with tongue-tie.
The evidence suggests that tongue-tie is genetic in origin as it seems to run in families and there may be environmental triggers, as yet unknown. It is imperative that the Department of Health guidelines on folic acid supplementation pre conception and in pregnancy are followed by parents and reinforced by healthcare professionals as this has been shown to be very effective in reducing cases of neural tube defects.