PDF] Sublingual vitamin B12 compared to intramuscular injection in patients with type 2 diabetes treated with metformin: a randomised trial. Semantic Scholar Efficacy of different routes of vitamin B12 supplementation for the treatment of patients with vitamin B12 deficiency: A systematic review and network meta analysis Irish Journal of Medical Science (1971 ) Efficacy of different routes of vitamin B12 supplementation for the treatment of patients with vitamin B12 deficiency: A systematic review and network meta analysis Irish Journal of Medical Science (1971 ) B12 Injections vs. Oral Supplements: Which Is Better? B12 Injections vs Oral Supplements: Which are more effective? Volonte