It helps prevent neural tube defects in the developing fetus. It is essential for the development of the baby's brain and nervous system. It is a key component of thyroid hormones, and a deficiency can lead to thyroid disorders like hypothyroidism. Some medications combine folic acid and iodine to support overall thyroid health.  In cases of dietary deficiencies or for individuals with limited access to iodine-rich foods, a combination of folic acid and iodine may be used as a dietary supplement to ensure they receive adequate levels of these important nutrients.