Vitamin B12 Injections For Chronic Pain

Below is a study poster presented to the Canadian Pain Society showing benefits of frequent B12 Injections. Unfortunately, a study found men with smoking history have a 3 times lung cancer rate so I have now restricted B12 injection use to women.

Some Notes on the Persistence of Subcutaneous B12 Analgesic Effects in Chronic Pain: Case Studies

Canadian Pain Society Poster Presentation Winnipeg, May 2013

Janice J. Montbriand, MSc, University of Northern British Columbia
Dr. M. Montbriand MD, Lakeshore Medical Clinic, Regina, Sk



Vitamin B12 injections have an analgesic effect in subsets of chronic pain. However, research has not investigated their analgesic effects over time, after the initial two week loading period. The goal of this case series is to present a follow-up on the persistence of the analgesic effects of self-administered subcutaneous B12 in a small chronic pain sample, and to include some recommendations for further research. 


Participants had various moderate to severe chronic pain conditions and inadequately controlled pain levels. They were instructed on self-administration of subcutaneous B12 injections (1000 mcg subcutaneously daily for a 2 week period, then as often as needed). Follow-up concerned reduction in pain, persistence of pain relief after the initial loading period, changes in activity levels noted, etc.


Respondents found that their pain relief from the B12 injections generally lasted an average of  3 days before more injections were needed. Certain subgroups seemed to benefit most from the injections.  Specific case studies are discussed.


The use of self-administered B12 injections in chronic pain holds promise as an adjunct treatment. Those unable to tolerate other treatments may particularly benefit; elderly patients would be well represented here. It is suggested that participants be taught to self-administer B12, 1000 mcg subcutaneously for a 2 week daily loading series, and then as needed. It is also suggested that further research may be needed to investigate whether those with comorbid mood disorders and/or pain with a neuropathic component benefit most from this treatment.


Two B12 injection RCTs resulted in improvements in chronic back pain over a two week period but did not offer any continuing data. This study was undertaken as a preliminary study of the persistence of the analgesic effects as well as  subgroup responses. Results are meant to guide further research.


  • Chronic back pain produces suffering, disability, and financial hardship.
  • 10% of Canadians over the age of fifteen experience chronic pain.
  • Much of chronic pain is of undefinable origin.
  • Opioid therapy is useful in only half of all cases and  reduces pain by only 20-50% (Bates, 2005).
  • Vitamin B12 is a low cost treatment that may augment other treatments.
  • B12 is well-tolerated by chronic pain populations, and side effects are rare.


  •   23 participants (11f, 12m) with chronic pain were instructed on self-administration of subcutaneous B12 injections (1000mcg).
  •  Injections were used as oral B12 may not increase blood levels over a short period of time.
  •  Participants were instructed to administer the injection once daily for a two week period, then as needed.
  •  Other pain issues/medications were noted.
  •   Participants were given a follow-up questionnaire concerning reduction in pain, persistence of pain relief, changes in activity levels noted, changes in mood, compliance, etc.

Vitamin B12

  • B12 supplementation may be useful in cases of chronic pain where no B12 deficiency exists.
  • B12’s neuroprotective and regenerative properties have been demonstrated in some studies
    • Neuroprotection – highlighted by improved eye function vs deterioration in long term glaucoma studies 1,2
  • Neuroregenerative – highlighted by improved results after nerve surgery 3,4
  • Two randomized controlled trials have found that frequent B12 injections can reduce chronic back pain scores by 15-25% compared to controls 3,4
  • There is a suggestion that Vitamin B12 may be helpful in cases of neuropathic pain 5,6
  • B12 use in diabetic neuropathy may lower pain levels 6
  • B12 has been shown to augment the effect of anticonvulsants (carbamazepine, gabapentin, lyrica), and anti-arthritic medications 7
  • B12’s beneficial effects on depression and fatigue have been debated 8
  • How long do these effects last, and which groups benefit most has not been delineated


  • Participants had been in pain for an average of 12 years (sd=7.8) and were an average age of 52 years (sd= 10). Pain onset was evenly distributed between traumatic and non-traumatic origins.
  • Participants reported a pretreatment average pain level of 5.8/10 (sd=1.3).
  •  Patients reported a high level of compliance during the initial two weeks.
  •  Participants who reported compliance during the initial two weeks were more likely to respond to treatment (х = 4.5, p = .034).
  •  More than half (56.5%) of our sample showed at least moderate response  (20% or more pain reduction) while 34% showed high response (30% or more reduction in pain).
  •  Both mean and median improvement among all participants was 20% (sd= 17%).
  •   Respondents reported that the pain relief lasted an average of  2-3 days after the loading period before they needed to repeat the injection.
  •  Some participants also noted changes in mood, fatigue, and activity level. (See case studies).
  • The current results are preliminary and meant to guide further research; however, several potential patterns emerged:
  •  Certain subgroups may have benefited more than others from the B12 injections:
  •  Those with neuropathic component to their  pain.
  •  Those with major mood disorders showed an increased response, as well as reporting improvements in mood. 
  •  Participants using neuropathic pain medications such as lyrica and gabapentin
  •  Certain subgroups may have  benefited less from B12 injections:
  •  Participants with severe pain or mild pain did not show a strong response.

Case 1

old disabled farmer with chronic disc disease in neck and back and SLAP lesion to right shoulder, with neck radiculitis features (interscapular and shoulder) and diffuse foot pain. He was compliant with the first two weeks and with subsequent usage. Participant found lyrica helpful. His average pain was 6/10; he found a 35% improvement with neck, back, and referred neck pains, and noted improvement in foot pain and with cramps and numbness in fingers.  His activity level on the farm was somewhat improved. He had had  depressive issues in past and a family history of bipolar disorder. He reported that  the treatment improved his mood moderately. After the initial loading period he found the B12 injections lasted about two days.

Case 2

A 57 year old disabled university-educated professional with MVA whiplash 10 years prior, intermittent left ulnar neuropathic pains, sciatica, musculoskeletal injuries and restless legs.  Participant was on gabapentin 1200 mg/day (up to 3600 mg at one point), diclofenac 150 mg/day and morphine. He reported his pain level as 5/10. He was compliant with initial 14 days of injections and had been “off and on” compliant with injections over the subsequent three months. He noticed a 50% improvement associated with the B12 injections when also taking gabapentin and a 30% improvement otherwise. Ulnar neuropathy improved 80% and neck pain 20%. He found the injections helped to moderately improve his activity level including increased yardwork. He had no mood disorder and reported no effect on mood.


  • Research has shown B12 can lower self-reported back pain, may be useful in some cases of neuropathy, and may augment some pain medications.
  •  This research investigated the effect of self-administered daily B12 (1000mcg) injections in a general back pain population.
  •  B12 injections (1000mcg) appeared to reduce pain and were well-tolerated
  • Reduction in pain level was comparable to some pain medications.
  • Those with neuropathic pain, on certain neuropathic pain medications, with major mood disorders, or with moderate pain seem to show the greatest response.
  • After the loading period, the effects lasted on average 2-3 days before patients would self-administer another dose.
  • Some patients reported improvements in mood, activity levels, and reduced fatigue.


1 Yamazaki Y et al . Effects of long-term methylcobalamin treatment on the progression of visual field defects in normal-tension glaucoma (2000). Current Therapeutic Research, 61 (7), 443–451.

2 Guo, W. et al. (2000). Mecobalamin in treating glaucoma visual field damage. Chinese Journal of New Drug and Clinical Remedies, 19 (4), 279-280.

3 Mauro G.L., Martorana U., Cataldo P., Brancato G. & Letizia G.Vitamin (2000). B12 in low back pain: a randomized, double-blind, placebo-controlled study. Eur Rev Med Pharmacol Sci, 4(3):53-8.

4 Chiu C.K., Low T.H., Tey Y.S., Singh V.A. & Shong H.K. (2011) The efficacy and safety of intramuscular injections of methylcobalamin in patients with chronic nonspecific low back pain: a randomized controlled trial. Singapore Med J, 52 (12), 868-73.

5 Solomon L.R. (2005). Cobalamin-responsive disorders in the ambulatory-care setting: Unreliability of cobalamin, methylmalonic acid and homocysteine testing, Blood 105, 978–985.

6  Graber J.J.  et al. (2010) Vitamin B12-responsive severe leukoencephalopathy and autonomic dysfunction in a patient with “normal” serum B12 levels. J Neurol Neurosurg Psychiatry , 81, 1369–1371.

7 Talaei A., Siavash M., Majidi H. & Chehre A. (2009) Vitamin B12 may be more effective than nortriptyline in improving painful diabetic neuropathy. International Journal of Food Sciences and Nutrition, 60(S5), 71-76.

8 Mauro G.L., Martorana U., Cataldo P., Brancato G. & Letizia G. (2000). Vitamin B12 in low back pain: a randomized, double-blind, placebo-controlled study. Eur Rev Med Pharmacol Sci. 4(3), 53-58.

9a Yong, Y. A. N., & Yan, L. I. (2009). The therapeutic effects of Carbamazapine combined Mecobalamine on central post-stroke pain. China Medical Herald, 10, 2004-2005.

9b Medina-Santillán, R., Reyes-García, G., Rocha-González, H.I., Granados-Soto, V. (2004) B vitamins increase the analgesic effect of ketorolac in the formalin test in the rat. Proc West Pharmacol Soc., 47, 95-99.

10 Amol P.M.,  Aashish S.M. &  Subhash L.B. (2008). Neuroprotective Effect of Ultra-High Dose of Methylcobalamin in Models of Mononeuropathy in Rats. Pharmacology online, 2, 282-295.

11 Yamazaki, K., Oda, K., Endo, C., Kikuchi, T & Wakabayshi, T.  (1994).  Methylcobalamin (methyl-B12) promotes regeneration of motor nerve terminals degenerating in anterior gracile muscle of gracile axonal dystrophy (GAD) mutant mouse. Neuroscience Letters, 170 (1), 195–197.

12 Bottiglieri, T. (2013). Folate, vitamin B12, and S-adenoosylmethionine. Psychiatric Clinics of North America, 36, 1-13.

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One Response to Vitamin B12 Injections For Chronic Pain

  1. Blurge says:

    Clearly, many thanks for the help in this question.

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