Ecofol is a brand of Calcium folinate pentahydrate. Calcium folinate pentahydrate is the salt of folinic acid, an adjuvant used in chemotherapy involving methotrexate. Folinic acid is a 5-formyl derivative of tetrahydrofolic acid. It is readily converted to other reduced folic acid derivatives and thus has vitamin activity equivalent to folic acid. Folinic acid, therefore, allows for some purine/pyrimidine synthesis to occur in the presence of dihydrofolate reductase inhibition, so that some normal DNA replication and RNA transcription processes can proceed. Folinic acid is used in combination with other chemotherapy drugs to either enhance effectiveness or as a chemoprotectant. Ecofol is also useful in megaloblastic anemia.