Oral vitamin B12 can change our practice

Abstract

Oral vitamin B12 can provide an effective alternative to intramuscular injections, so giving patients a choice and reducing costs in primary care. This study investigated the effectiveness, safety, and acceptability of oral vitamin B12 as replacement therapy in patients with vitamin B12 deficiency in a city general practice population. Forty patients previously maintained on vitamin B12 injections were given 1000 µg of oral cyanocobalamin daily for up to 18 months. All the patients maintained satisfactory serum B12 levels and showed normal haematology and neurology. Compliance and acceptability was excellent. The time for a change in practice has indeed arrived. V itamin B12 is given intramuscularly in the UK despite the fact that oral vitamin B12 in sufficiently large doses is equally effective. Historically, this passive absorption mechanism provided the first treatment for pernicious anaemia.1 2 In the absence of an intact ileum or intrinsic factor, 1.2% of an oral dose of vitamin B12 will pass across the small bowel.3 4 The dose absorption ratio is remarkably constant in an oral dose range from 1 to 100 000 µg of hydroxocobalamin and adequate levels of serum vitamin B12 have resulted using oral doses above 500 µg daily.5-9 Reflecting this, most vitamin B12 replacement therapy is now given orally in Sweden 10 11 and in the USA it is becoming a more popular mode of treatment. Nursing time spent on intramuscular injections is costly-an assessment of the costs of administering injections of vitamin B12 made in 1997 to the 89 patients in our combined inner city practice of 19 000 suggested that substantial savings could be made with an oral preparation.12 An oral preparation of vitamin B12 (Cytacon 50 µg) is available in the UK but the NHS licence restricts its use to vitamin B12 deficiency of dietary origin and for vegans. PATIENTS AND METHODSThis was a prospective case series of 50 of the 108 eligible patients with vitamin B12 deficiency within the combined practice populations of 19 000 patients. Ten patients had pernicious anaemia as confirmed by a positive Schilling test and/or raised intrinsic factor antibody (as confirmed by the autozyme test for anti-intrinsic factor antibody). Nine of the patients had gastrointestinal surgery related vitamin B12 deficiency and the remainder were intrinsic factor negative. Exclusions were because of refusal, cognitive impairment, or acute illness. Patients were recruited to the study at the rate of two or three per week but the study ended on a specific date such that patients took study medication for variable periods of time. There were 17 males and 33 females with an age range of 31 to 90. Ethical approval was obtained from the East Birmingham Local Research and Ethics Committee. At study entry patients completed a medical history and received a physical examination with emphasis on cognition and the nervous system. Repeat medical histories were taken every six months. Physical examination was repeated in all patients at the end of the study and if the serum vitamin B1...

Chronic Hypergastrinemia: Causes and Consequences

“…Consequently, serum gastrins >1000 pg/mL are not diagnostic of either ZES or PA, and the distinction between the 2 requires clinical correlation. Although no effective therapy for CAG-A exists, the clinical consequences of PA can be avoided or largely reversed by oral or parenteral vitamin B 12 supplementation [32].…”

Pernicious Anaemia

“…[6] Accurate diagnosis is also important because the condition now can be treated by oral vitamin B12 rather than by the vitamin given by intramuscular injection. [7] Experimental mouse models have contributed significantly to our knowledge of the pathogenesis of the gastric lesion of autoimmune gastritis. [8] These mouse models are strikingly similar to their human counterparts in gastric pathology and, like the human disease, are characterized by circulating parietal cell antibodies directed against gastric H/K ATPase, the enzyme responsible for acid secretion in the stomach.…”

Megaloblastic Anemia and Other Causes of Macrocytosis

“…46 In cases of deficiency due to inadequate intake, food-cobalamin malabsorption and pernicious anemia, oral cyanocobalamin administered at 1000-2000 µg/day for 1 month, followed by 125-500 µg/day is recommended and considered a safe and effective method of treatment. 47 Other oral administration regimens have demonstrated efficacy and have proven to be equally as effective as intramuscular administration. 48,49 In some cases, nasal or sublingual cyanocobalamin may also be useful in replenishing vitamin B12 stores.…”