The folic acid utilization capacity test checks the body’s ability to metabolize folic acid, as genetic testing has revealed two genes that are closely related to folic acid utilization capacity. Each person’s ability to metabolize folic acid is different, and if only the recommended amount of folic acid is taken, some people will have just enough, while others may have less or more. Folic acid has a stimulating effect on the development of the baby’s nerve cells as well as brain cells. Deficiency of folic acid in pregnant women is a major cause of fetal neural tube abnormalities, but over-supplementation of folic acid is also prone to adverse outcomes such as increased risk of breast cancer, reduced sperm motility in men and slow fetal growth. The folic acid utilization capacity test allows us to understand the individual folic acid metabolism capacity and then choose an individualized folic acid supplementation program according to the situation to avoid under- or over-supplementation of folic acid by the organism.