Folate is also known as vitamin B9; folic acid is the synthetic or supplement form that must be converted to folate. Sources of folate are leafy green vegetables, broccoli, legumes, and liver. Unlike B12, folate is not stored for a long period.
Folate is absorbed in the duodenum and jejunum in an acid environment and transported via proteins known as proton-coupled folate transporter (PCFT) and reduced folate carrier (RFC). Unlike IF and B12, however, these proteins are not clinically significant.
Causes of folate deficiencies include lack of vegetables and fruit in the diet, gastrointestinal diseases such as Crohn's and celiac disease, certain drugs such as methotrexate, and alcohol misuse.
