Do Vitamin B12 Injections Lead to Improvement When Treating Voice-Related Symptoms in Professional Singers?

What is the effect of empirical vitamin B12 injections administered for improvement of mild singing-related symptoms? 

BOTTOM LINE 

After empirical B12 injection, self-reported voice measures in singers show no meaningful difference compared with placebo. 

BACKGROUND: Vitamin B12 is a required nutrient for performing essential functions, and it has been suggested that B12 deficiency is associated with chronic cough and laryngeal hyper-responsiveness. Many singers/vocal professionals believe that empirical B12 injections may improve mild singing-related symptoms, but no objective evidence exists to support or refute these claims. 

COMMENT: In a bit of high quality myth-busting, the USC team looked prospectively at the use of B12 shots in professional singers with voice concerns. Twenty subjects were enrolled in a placebo-controlled cross-over trial that was double-blinded—as good as we can do in a study—and found that despite generations of enthusiasm and belief in this practice in the performing arts community, there was no real advantage or impact of B12 shots over placebo on vocal performance. —Albert L. Merati, MD

STUDY DESIGN: Randomized trial. 

SETTING: Department of Otolaryngology–Head and Neck Surgery, Rabin Medical Center, Petach Tikva, Israel. 

SYNOPSIS: Via targeted advertisement, researchers recruited 20 active vocational singers with mild voice-related symptoms such as reduced stamina, vocal fatigue, or increased singing effort. Exclusion criteria included known vitamin B12 deficiency, active/recent vitamin B12 treatment, bleeding disorders, history of laryngeal pathology, and current dysphonia. Participants were randomized to receive an intramuscular injection of either vitamin B12 or placebo. After at least four weeks, the groups were crossed over to receive the opposite injection. Pre-injection, participants completed several questionnaires to gauge vocal state at baseline, then again post-injection at several time intervals. Change in Singing Voice Handicap Index-10 questionnaire score pre-injection and 72 hours post-injection were the primary outcome measure. Although vitamin B12 scores demonstrated improvements over pre-injection scores, they were not different from those observed post-placebo injection. Both sets of improvements failed to reach the estimated minimal clinically important difference. Authors conclude that, given the importance of avoiding use of ineffective treatment due to possible adverse effects, the unnecessary use of vitamin B12 should be avoided. Study limitations included lack of results correlation with objective voice measures. 

CITATION: Shoffel-Havakuk H, Lava CX, Reuven Y, et al. Effect of vitamin B12 injection on the vocal performance of professional singers: a randomized, double-blind, placebo-controlled, crossover trial. JAMA Otolaryngol Head Neck Surg. 2021;147:9-15.