Serum and urinary folate in liver disease.

During the active phase of viral hepatitis urinary folate loss was found to be 8.0 to 48.3 (mean 31.1) mug./day, compared with a normal urinary folate excretion of 0.1 to 18.0 (mean 9.5) mug./day. In cirrhosis and cardiac failure with congestive hepatomegaly the corresponding values were 25.8 to 55.0 (mean 35.7) mug./day and 2.5 to 61.6 (mean 26.9) mug./day, respectively. Urinary folate loss may be a significant factor in the aetiology of folate deficiency of chronic liver disease, particularly when dietary intake is poor.After prolonged dialysis in Visking casing urinary folate was almost totally dialysable, but an appreciable fraction of serum folate was not, even after 72 hours. The dialysable (free) folate fraction of serum and urine disappeared maximally during the first six hours' dialysis, and was virtually cleared after 24 hours' dialysis; clearance curves in normal individuals and in liver disease were comparable. The non-dialysable serum folate fraction was of similar magnitude in all subjects studied, in spite of marked variation in total folate, and probably represented protein-bound folate.