Nearly two-thirds of vitamin B12 injections in older adults may be unnecessary


Publisert 24.07.2019

Approximately 64% of vitamin B12 injections in adults aged 65 and older may be inappropriate, resulting in millions in unnecessary health care costs, according to findings published in JAMA Internal Medicine.

"Randomized clinical trials demonstrate that treating vitamin B12 ... deficiency with oral supplementation substantially increases serum B12 levels compared with intramuscular injections, with no difference in hematologic or neuropsychiatricoutcomes," William K. Silverstein, MD, of the department of medicine at the University of Toronto, and colleagues wrote. "Despite this, some primary care physicians still inappropriately administer B12 injections to elderly patients."

Researchers conducted a population-based retrospective cohort study with information collected from health system administrative databases to determine the prevalence of inappropriate B12 supplementation. Those aged 65 years and older who received at least one intramuscular B12 prescription between Jan. 1, 2011, and Sept. 30, 2015, were included in the study.

B12 supplementation was considered inappropriate for patients with normal serum B12 levels (221 pmol/L) or in those who did not have a documented B12 level in the year leading up to the first B12 intramuscular prescription.

Within the study period, 405,469 intramuscular B12 prescriptions were made to 146,850 people, 63.7% (n = 93,615) of whom did were deemed inappropriate. In the year prior to first B12 injection, 25.5% (n = 37,487) had normal B12 levels and 38.2% (n = 56,128) did not have a documented B12 level.

Among those without a B12 level documented within a year of injection, 43.1% (n = 24,175) had ever had their B12 level measured, which occurred a mean 1,033.5 days prior to first B12 prescription. Researchers found that only 35.3% (n = 8,539) of those who had documented B12 levels and received an injection had marginally deficient levels of B12.

Silverstein and colleagues estimated that inappropriate B12 injection prescribing cost approximately CAD$45 million (approximately US$34.2 million) each year.

"Further studies should examine this issue, to inform quality improvement initiatives aimed at reducing this unnecessary care," Silverstein and colleagues wrote. - by Erin Michael

Disclosures: Silverstein reports no relevant financial disclosures. Please see study for all other authors' relevant financial disclosures.