Extra vitamins are needed to repair tissue damage and compensate for diminished hepatic storage during viral hepatitis. Coenzyme-B12 has recently been synthesized and ought to have a favourable effect on the damaged liver cell as has previously been reported for cyanocobalamin, since it is better absorbed by oral administration and to a greater extent accumulated in the liver. Two groups of patients from the same hepatitis A epidemic were treated with either coenzyme-B12 or cyanocobalamin. A more rapid return of serum aminotransferase (S-ALAT) levels to normal was observed in the group treated with coenzyme-B12.