Folic acid, vitamin B12 and vitamin B12 binding proteins in patients with neuroblastoma.

Serum vitamin B12, serum and red cell folate and serum vitamin B12 binding proteins were determined in 18 patients with neuroblastoma, with ages ranging from 8 months to 14 years. A mean value of serum vitamin B12 level was slightly but not significantly lower than that of the normal subjects but all of them had serum vitamin B12 levels over 150 pg/ml. There was no relationship between serum vitamin B12 levels and hemoglobin, hematocrit or white cells. Transcobalamin I (TCI) was significantly increased resulting in slightly elevated UBBC and normal TBBC levels in these patients. This could be a compensatory mechanism for the low serum vitamin B12 by increasing the unsaturated vitamin B12 binding capacity of TCI. All these findings indicated that the status of vitamin B12 in patients with neuroblastoma was within the normal limits. Treatment of neuroblastoma by giving a high dose of vitamin B12 would therefore not give any direct therapeutic effect. Both serum and red cell folate concentrations were significantly lower in the group of patients. As only 2 out of 18 patients had low serum folate and none of them had red cell folate lower than the lower limit of normal subjects; therefore these patients were only in the state of negative folate balance.