A 71-year-old woman was treated with radiotherapy for carcinoma of the cervix. Nine year later she was found at laparotomy to have a thickened narrow ileum. At the time she had an iron-deficiency anaemia and when this was treated the blood picture changed to that of a severe megaloblastic anaemia. This was due to cobalamin deficiency resulting from malabsorption of cobalamin by the damaged ileum.

It is well established that accumulation of methylmalonic acid may provide an early clue to the existence of tissue cobalamin (vitamin B12) deficiency. To verify whether methylmalonic acid accumulates in adult heterozygotes for inherited methylmalonic-acidaemia and thereby gives "false" positive test results for cobalamin deficiency, we measured the concentration of methylmalonic acid in serum ...

Because cobalamin deficiency is routinely treated with parenteral cobalamin, we investigated the efficacy of oral therapy. We randomly assigned 38 newly diagnosed cobalamin deficient patients to receive cyanocobalamin as either 1 mg intramuscularly on days 1, 3, 7, 10, 14, 21, 30, 60, and 90 or 2 mg orally on a daily basis for 120 days. Therapeutic effectiveness was evaluated by measuring hemat...

Cobalamin neuropathy was produced in Cape fruit bats (Rousettus aegyptiacus) by a cobalamin-free diet combined with intermittent exposure to nitrous oxide, which inactivates cobalamin. Cobalamin-deficient bats had low hepatic methylmalonyl-CoA mutase holoenzyme activity, with elevated plasma and urinary methylmalonic acid levels. No significant changes could be demonstrated in the concentration...

BACKGROUND Cobalamin deficiency is commonly associated with chronic enteropathies (CE) in dogs and current treatment protocols recommend parenteral supplementation. In humans, several studies have reported equal efficacy of oral and parenteral cobalamin administration of cobalamin. OBJECTIVES To retrospectively evaluate whether oral cobalamin supplementation can restore normocobalaminemia in ...

AIMS To compare the efficacy of sublingual and oral administration of 500 micro g of cobalamin in subjects with cobalamin deficiency. MATERIALS AND RESULTS Thirty subjects with low serum concentrations of cobalamin participated in the study. Subjects were randomly allocated to receive one tablet daily of 500 micro g cobalamin sublingually or orally, or two tablets daily of a vitamin B complex...