Crude or Refined Intrinsic Factor in Preparations for the Oral Treatment of Pernicious Anaemia

A report is given of a comparative study of the absorption of vitamin B12 with the aid of crude or purified intrinsic factor preparations. A crude hog's pylorus material, contained in Hepaforte®, was shown to have an intrinsic factor activity, in relation to its 12 binding capacity, about 40 per cent of that in a purified material used in Bendogen®. No qualitative difference in intrinsic factor activity could be traced for the two materials studied. In pernicious anaemia patients, refractory to standard treatment with vitamin B12 + intrinsic factor, the B12 absorption is generally in the normal range, when the amount of intrinsic factor material given is sufficiently high. Long term clinical trials show, however, that some refractory patients show subnormal serum B12 values even after intrinsic factor doses much higher than those generally recommended. Also in these studies no fundamental difference was found between crude and purified intrinsic factor materials. Oral treatment of pernicious anaemia with vitamin B12 plus intrinsic factor has no place in modern therapy, especially in view of our present knowledge that a daily oral dose of 1 mg vitamin B12 without intrinsic factor gives full protection in all cases of B12 deficiency.