Oral or intramuscular vitamin B12?

Vitamin B(12) deficiency is common, becoming more so with age, and estimates of its population prevalence have ranged from 1.5% to 15%. If untreated, it can lead to megaloblastic anaemia and irreversible neurological complications. In the UK, the usual treatment is regular intramuscular injections of hydroxocobalamin. High-dose oral vitamin B(12) replacement is standard practice in some other countries and less costly. Here we review issues around adopting an oral vitamin B(12) replacement regimen more widely in the UK.