Vitamin B12 Shot Benefits Include Potential Help for Chronic Fatigue

Vitamin B12 shot benefits for individuals suffering from chronic fatigue are significant, say researchers, but most patients need the injections every week, long-term, and also require high doses of folate.

b12 shot may provide benefits

Remember that there are many factors that can play into whether you experience significant B12 shots benefits or not.

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If you’re suffering from chronic fatigue syndrome (CFS) and have ever tried or considered trying vitamin B12 injections, you’re not alone. Many patients who suffer from relentless fatigue and the many other symptoms of CFS, such as pain and disrupted sleep, know about the potential vitamin B12 shot benefits.

While some CFS patients have only a mild response to the injections, in others the response is dramatic and their symptoms are significantly ameliorated, allowing these select patients to get back to a productive life.

Why would vitamin B12 shot benefits be so significant for some people with chronic fatigue, but not for others?

What Makes B12 Shots Effective for CFS?

So what is it that makes Vitamin B12 shots potentially effective for chronic fatigue syndrome? Recently, a group of researchers affiliated with the Institute of Neuroscience and Physiology at Sweden’s Gothenburg University published their results from a study attempting to answer to this question. The researchers drew from their 15 years of experience studying CFS patients and treating them with vitamin B12. During this time, they had already determined that CFS patients respond best to the injective form of B12 therapy.

For this study, they examined clinical data from 38 female patients with CFS who had been on B12 injections at least once a week for six months and up to several years, all of whom expressed favorable response, from mild to dramatic. Here’s what they found:

  • All but one (93 percent) of the good responders were treated with methylcobalamin, the biologically active form of vitamin B12. A significantly high proportion (43 percent) of mild responders were using hydroxocobalamin, a non-biologically active form.
  • The methylcobalamin used by almost all of the good responders was more concentrated (5 mg/mL) than the hydroxocobalamin (1 mg/mL) used by many of the mild responders.
  • Good responders had, on average, been treated with injections more frequently (every 3.8 ± 1.9 days) than mild responders (every 5.8 ± 1.7 days).
  • The good responders also took a higher daily dose of oral folic acid (6.7 ± 6.6 mg per day) compared to the mild responders (1.9 ± 2 .0 mg per day).
  • The good responders were more often taking thyroid hormones.
  • None of the good responders were using prescription opioids or strong analgesics, while a majority of mild responders were using them on a daily basis.

Conclusions About B12 Shot Benefits for CFS

Based on the findings described above, researchers concluded that frequent injections of the high-concentrated, methylcobalamin form of vitamin B12, combined with an individual daily dose of oral folic acid, may provide high enough blood levels of these compounds for safe and effective relief of fatigue and other symptoms in some individuals suffering from CFS.*

The exact optimal dose and frequency of methylcobalamin and folic acid is different for every individual and takes time and experimentation to determine, according to the researchers.

In general, CFS patients’ symptoms worsened if they tried to switch to oral vitamin B12 supplements or when they tried to lengthen the time between injections. Moreover, certain opioid analgesics and other drugs commonly taken by CFS patients with fibromyalgia/muscle pain may interfere with and counteract the effects of the B12/folic acid.*

Furthermore, CFS patients should be tested for co-existing thyroid dysfunction. When needed, thyroid treatment may contribute to the overall treatment effect when used in combination with B12 and folic acid.

What to Do If You Want to Give B12 Shots a Try

Are you suffering from CFS and have tried, or considered trying, vitamin B12 injections? Remember that there are many factors that can play into whether you experience significant B12 shot benefits or not.

  • Try the methylcobalamin form of B12.
  • Work with your physician to experiment to find the optimal dose of both B12 and folate for you as an individual.
  • Try to stop taking analgesics.
  • Talk to your doctor about getting thoroughly tested for a thyroid disorder.

To help you and your physician find the best plan for you, take the full text of the published paper, free here, to your healthcare provider for a discussion. Don’t give up and keep advocating for yourself!

Share Your Experience

If you have tried B12 injections, tell us whether they worked for you, using the Comments section below.

*For readers interested in learning more about how vitamin B12 and folic acid likely work to treat CFS and why analgesics and other certain drugs might interfere with the effectiveness of these B vitamins, the full text of the paper, available for free by clicking here, provides an interesting perspective and discussion.


Source: \PLoS One. 2015; 10(4): e0124648.


Originally published in 2015, this post is regularly updated.


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UHN Staff

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