A recent clinical trial published in the journal Pain Physician found that treating low vitamin D levels improved pain intensity and mobility among patients with chronic low back pain (CLBP).
Low back pain is the leading cause of disability worldwide. In fact, one-half of all working Americans report back pain symptoms each year. Medical professionals often advise patients who suffer chronic back pain to use the most conservative treatment first to avoid potential side effects. Since vitamin D is affordable and very rarely accompanied by unwanted side effects, researchers have gained an interest in the potential treatment of CLBP with vitamin D.
Studies have shown a link between low vitamin D levels and chronic musculoskeletal pain, including low back pain. Up to 83% of patients with CLBP are vitamin D deficient. The mechanisms responsible for this relationship remain unclear. Theoretically, two possible explanations have been proposed.
Firstly, vitamin D supplementation has been found to improve bone density and muscle mass, which may result in a reduction of pain. Secondly, low vitamin D status has been linked to heightened central sensitivity, a condition of the nervous system associated with the development and severity of chronic pain.
Heightened central sensitivity causes a patient to become more sensitive to pain, or in other words, the patient feels more pain with less provocation. Studies have found that vitamin D can modulate this response by reducing the excitability of nerve cells (neurons). Furthermore, inflammation also plays a role in the development of heightened central sensitivity, and vitamin D elicits anti-inflammatory effects.
On a side note, migraine and fibromyalgia are often characterized by a central hypersensitivity. Therefore, vitamin D’s ability to modulate central hypersensitivity may also explain the mechanism underlying the success of vitamin D supplementation for the treatment of fibromyalgia and migraines.
Researchers recently conducted a clinical trial to investigate the efficacy of vitamin D supplementation for the treatment of CLBP. The study included 68 CLBP patients with vitamin D deficiency as defined by levels less than 30 ng/ml. All patients supplemented with 60,000 IU of oral vitamin D3 every week for 8 weeks.
The researchers assessed the efficacy of vitamin D by using the Visual Analog Scale (VAS) and modified Oswestry disability questionnaire (MODQ), which measured pain intensity and functional disability, respectively. These measurements were taken at baseline, 2, 3 and 6 months post-supplementation. Lastly, the researchers quantified the proportion of patients who achieved effective pain relief, defined as > 50% reduction in pain score after three months post-supplementation.
Here is what the researchers found:
- Average vitamin D levels increased from 12.8 ng/ml at baseline to 36.07 ng/ml after 8 weeks of supplementation (p < 0.01).
- Pain scores significantly and progressively reduced at 2, 3 and 6 months (p < 0.001).
- Functional ability significantly improved at 2, 3 and 6 months compared to baseline (p <001).
- Effective pain relieve was achieved in 53% and 63.2% of the patients at 3 and 6 months, respectively.
The researchers concluded,
“The present study shows that vitamin-D supplementation can improve the pain and disability in patients with CLBP.”
They also warn readers that these results should be interpreted carefully due to the study’s limitations, which include its lack of control group, a relatively small sample size and a short duration. Therefore, randomized controlled trials using comparative doses are needed.
Tovey, A. & Cannell, JJ. Recent clinical trial discovers vitamin D supplementation reduces chronic low back pain. The Vitamin D Council Blog & Newsletter, 2017.