Objective The aim of this study was to estimate the cost-savings attainable if all patients aged ≥65 years in Alberta, Canada, currently on intramuscular therapy were switched to oral therapy, from the perspective of a provincial ministry of health.

Setting Primary care setting in Alberta, Canada.

Participants Seniors of age 65 years and older currently receiving intramuscular vitamin B₁₂ therapy.

Intervention Oral vitamin B₁₂ therapy at 1000 μg/day versus intramuscular therapy at 1000 μg/month.

Primary and secondary outcome measures Cost saving from oral therapy over intramuscular therapy, from the perspective of the Alberta Ministry of Health, including drug costs, dispensing fees, injection administration fees, additional laboratory monitoring and physician visit fees.

Results Over 5 years, if all Albertans aged 65 years and older who currently receive intramuscular B₁₂ are switched to oral therapy, our model found that $C13 975 883 can be saved. Even if no additional physician visits are billed for among patients receiving intramuscular therapy, $C8 444 346 could be saved from reduced administration costs alone.

Conclusions Oral B₁₂ therapy has been shown to be an effective therapeutic option for patients with vitamin B₁₂ deficiency, yet only three provinces and the Non-Insured Health Benefits program include oral tablets on their formulary rather than the parenteral preparation. To ensure judicious use of limited health resources, clinicians and formulary committees are encouraged to adopt oral B₁₂ therapy as a clinically and cost-effective first-line therapy for vitamin B₁₂ deficiency.