The effect of folate deficiency and different doses of folic acid supplementation on liver diseases.

The liver has multiple functions such as detoxification, metabolism, synthesis and storage. Folate is a water-soluble vitamin B₉, which participates in one-carbon transfer reactions, maintains methylation capacity and improves oxidative stress. Folic acid is a synthetic form commonly used as a dietary supplement. The liver is the main organ for storing and metabolising folate/folic acid, and the role of folate/folic acid in liver diseases has been widely studied. Deficiency of folate results in methylation capacity dysfunction and can induce liver disorders. However, adverse effects of excessive use of folic acid on the liver have also been reported. This review aims to explore the mechanism of folate/folic acid in different liver diseases, promote further research on folate/folic acid and contribute to its rational clinical application.