Sensitivity to vitamin B12 concentrate.

Abstract

It has been suggested that vitamin B 12 is satisfactory therapy for patients who are sensitive to liver. 1 This report concerns a patient extremely sensitive to liver extract who also reacted to vitamin B 12 concentrate but showed no evidence of sensitivity to crystalline vitamin B 12 . REPORT OF CASE The patient was known to have had pernicious anemia for five years and was first treated with injections of purified liver extract. He improved and voluntarily discontinued therapy after one year's treatment. One and one-half years later treatment was resumed with purified beef liver extract. The patient improved but later experienced reactions to injectable liver extract and was started on oral therapy with liver-stomach concentrate and iron. Therapy was adequate for some time, but in August 1949 the man had neurologic and hematologic relapse. It was learned that he had been taking folic acid 7.5 mg. daily in addition