Oral vitamin B12 therapy in the primary care setting: a qualitative and quantitative study of patient perspectives

Although oral replacement with high doses of vitamin B12 is both effective and safe for the treatment of B12 deficiency, little is known about patients' views concerning the acceptability and effectiveness of oral B12. We investigated patient perspectives on switching from injection to oral B12 therapy.

This study involved a quantitative arm using questionnaires and a qualitative arm using semi-structured interviews, both to assess patient views on injection and oral therapy. Patients were also offered a six-month trial of oral B12 therapy. One hundred and thirty-three patients who receive regular B12 injections were included from three family practice units (two hospital-based academic clinics and one community health centre clinic) in Toronto.

Seventy-three percent (63/86) of respondents were willing to try oral B12. In a multivariate analysis, patient factors associated with a "willingness to switch" to oral B12 included being able to get to the clinic in less than 30 minutes (OR 9.3, 95% CI 2.2-40.0), and believing that frequent visits to the health care provider (OR 5.4, 95% CI 1.1-26.6) or the increased costs to the health care system (OR 16.7, 95% CI 1.5-184.2) were disadvantages of injection B12. Fifty-five patients attempted oral therapy and 52 patients returned the final questionnaire. Of those who tried oral therapy, 76% (39/51) were satisfied and 71% (39/55) wished to permanently switch. Factors associated with permanently switching to oral therapy included believing that the frequent visits to the health care provider (OR 35.4, 95% CI 2.9-432.7) and travel/parking costs (OR 8.7, 95% CI 1.2-65.3) were disadvantages of injection B12. Interview participants consistently cited convenience as an advantage of oral therapy.

Switching patients from injection to oral B12 is both feasible and acceptable to patients. Oral B12 supplementation is well received largely due to increased convenience. Clinicians should offer oral B12 therapy to their patients who are currently receiving injections, and newly diagnosed B12-deficient patients who can tolerate and are compliant with oral medications should be offered oral supplementation.