Vitamin B9 (Folate)

Vitamin B9 refers to folate, a class of pteridine derivatives such as folic acid. Folates are generally processed by the body into the active compound THF, which serves as a cofactor in numerous enzymatic reactions, generally involving the transfer of a methyl group (one carbon with attached hydrogens). 

Folate deficiency can cause birth defects such as spina bifida and other neural tube defects. It can also cause megaloblastic macrocytic anemia, where red blood cells fail to fully mature. Whole grains and legumes are excellent sources of vitamin B9.