- Methylmalonic acide (MMA) serum concentration < 200 nmol/L and homocysteine (Hcy) concentration < 10 μmol/L at screening, or receipt of 1 mg daily oral folic acid for at least 10 days prior to the planned start of pralatrexate and 1 mg intramuscular vitamin B12 within 10 weeks of the planned start of pralatrexate.