Humans obtain folate from dietary sources, including fruits, green and leafy vegetables, yeast, and organ meats. Folate is absorbed from the small intestine and stored in the liver. Low folate intake, malabsorption, pregnancy, and drugs such as phenytoin are causes of folate deficiency. Folate deficiency is also associated with chronic alcoholism. Both folate and vitamin B12 deficiency cause macrocytic anemia.
Appropriate treatment depends on the differential diagnosis of the deficiency.
Serum folate measurement provides an index of folate status. However, because folate is much more concentrated in RBCs than in serum, RBC folate measurement more closely reflects tissue stores and is considered the most reliable indicator of folate status. Biochemical aspects of hematology. In Tietz textbook of clinical chemistry , 2nd ed. CA Burtis and ER Ashwood, eds.