Back to Basics: The Impact of B-Vitamins on Low Back Pain

The Consequences of Low Back Pain

As the second most frequent symptom-related reason for outpatient visits after the common cold, low back pain represents one of the most common ailments encountered in clinical practice, with a lifetime prevalence of up to 84%.¹ Low back pain is also associated with absenteeism/presenteeism in the workplace, altered functional status, and lower health-related quality-of-life.  Collectively, these symptoms profoundly impact mobility and the ability to perform activities of daily living (ADL), ultimately resulting in considerable economic and societal consequences.^2,3,4

B-Vitamins as an Adjunct to Current Standards of Care

Currently established global clinical practice guidelines consistently recommend the use of acetaminophen as first-line and NSAIDs (e.g. ibuprofen, diclofenac and naproxen) as second-line treatments for low back pain.⁵ While both acetaminophen and NSAIDs have well-established efficacy and safety profiles, there exists a significant unmet need for patients who remain uncontrolled despite maximal therapy.  Recent research has highlighted the potential role of vitamin B complex – defined in the literature as 1 mg of vitamin B12, 50-100 mg of vitamin B1 and 50-100 mg of vitamin B6 – as an adjunct to NSAID therapy in patients otherwise uncontrolled on their current therapeutic regimens and who may require intensification.[Ibid]

The DOLOR study, a randomized, double-blind study, assessed the efficacy and safety of twice-daily oral administration of either vitamin B complex combination therapy (group DB; 50 mg diclofenac + 50 mg vitamin B1, 50 mg vitamin B6 and 1 mg vitamin B12) or diclofenac monotherapy, (group D; 50mg diclofenac).  After 3 days of treatment, a statistically significantly higher proportion of subjects in group DB (n = 87; 46.5%) than in group D (n = 55; 29%) terminated the study due to treatment success (χ2: 12.06; p = 0.0005). According to the study authors, combination therapy yielded superior results in pain reduction, improvement of mobility and functionality as assessed by the Visual Analog Pain Scale (VAS).⁶

A number of study post-hoc analyses further reinforce the utility of this adjunctive approach. For example, Geller et al. recently demonstrated a statistically significant correlation between VAS scores and FFD (finger-to-floor distance) scores in DOLOR, demonstrating the beneficial effect of adjunctive vitamin B complex on both mobility and pain intensity among patients presenting with low back pain.  Geller et al. similarly demonstrated, using the Patient Functionality Questionnaire (PFQ), that patients receiving adjunctive vitamin B complex showed greater improvement than NSAIDs alone in areas related to sleep quality, mobility, ability to wash and dry, ability to walk distances, and posture comfort.⁷ A recent systematic meta-analysis by Marquez et al. largely confirms the aforementioned findings.⁵

Proposed Mechanisms

While the exact mechanisms for vitamin B complex efficacy in the treatment of low back pain are still largely unknown, the prevailing hypothesis involves increasing afferent inhibitory control of nociceptive neurons at the spinal cord, improving sensory nerve conduction velocity and reducing neuronal hyperexcitability by altering sodium currents in injured dorsal root ganglia.^8,9,10 In combination with NSAID therapy, this has the potential to produce profound synergistic effects.⁵

Future Outlook

Recent research looks promising; yet, there is much to discover in the application of vitamin B complex for lower back pain management.  Primarily, the subjective nature of pain, as well as the vast disparity in treatment responses to NSAIDs across various patient subgroups necessitate an individualized approach to both future research programs as well as clinical guidelines attempting to address this widespread clinical concern.