1. Any of several naturally occurring water-soluble compounds of the vitamin B complex that function in the metabolism of nucleic acids and amino acids and are found in leafy greens, fresh fruits, legumes, liver, and eggs, or are produced in the body by metabolism of folic acid. Folate deficiency during pregnancy can lead to neural tube defects in newborns.

2. Folic acid or any of various derivatives and reduced forms of folic acid.