Abstract
Background
Vitamin B is frequently used for treating peripheral neuropathy but its efficacy is not clear.
Objectives
The objective of this review was to assess the effects of vitamin B for treating generalised peripheral neuropathy.
Search methods
We searched the Cochrane Neuromuscular Disease Group Trials Register (searched August 2005), MEDLINE (January 1966 to September 2005), EMBASE (January 1980 to September 2005), Philippine databases (searched September 2005) and reference lists of articles. We also contacted manufacturers and researchers in the field.
Selection criteria
Randomised and quasi-randomised trials where vitamin B was compared with placebo or another treatment in generalised peripheral neuropathy.
Data collection and analysis
Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information.
Main results
Thirteen studies involving 741 participants with alcoholic or diabetic neuropathy were included. In the comparison of vitamin B with placebo, two small trials showed no significant short-term benefit in pain intensity while one of the trials showed a small significant benefit in vibration detection from oral benfotiamine, a derivative of thiamine. In the larger of two trials comparing different doses of vitamin B complex, there was some evidence that higher doses resulted in a significant short-term reduction in pain and improvement in paraesthesiae, in a composite outcome combining pain, temperature and vibration, and in a composite outcome combining pain, numbness and paraesthesiae. There was some evidence that vitamin B is less efficacious than alpha-lipoic acid, cilostazol or cytidine triphosphate in the short-term improvement of clinical and nerve conduction study outcomes but the trials were small. There were few minor adverse effects reported.
Authors’ conclusions
There are only limited data in randomised trials testing the efficacy of vitamin B for treating peripheral neuropathy and the evidence is insufficient to determine whether vitamin B is beneficial or harmful. One small trial in alcoholic peripheral neuropathy reported slightly greater improvement in vibration perception threshold with oral benfotiamine for eight weeks than placebo. In another small study, a higher dose of oral vitamin B complex for four weeks was more efficacious than a lower dose in reducing symptoms and signs. Vitamin B administered by various routes for two to eight weeks was less efficacious than alpha-lipoic acid, cilostazol or cytidine triphosphate in short-term improvement of clinical and nerve conduction study outcomes. Vitamin B is generally well-tolerated.
Plain language summary
Vitamin B for treating disorders of the peripheral nerves
Peripheral neuropathy is a disorder of the peripheral nerves resulting from different causes, such as diabetes mellitus and alcoholism, leading to pain, numbness or weakness of the limbs and other problems. Vitamin B is commonly used to treat peripheral neuropathy but it is not clear if it helps. This review of 13 trials on diabetic and alcoholic peripheral neuropathy with a total of 741 participants showed only one study that suggested possible short-term benefit from eight-week treatment with benfotiamine (a derivative of vitamin B1) with slightly greater improvement in vibration perception threshold compared to placebo. Vitamin B complex when given in a higher dose administered for four weeks was more efficacious than a lower dose in reducing pain and other clinical problems based on another study. Two to eight weeks of treatment with vitamin B was less efficacious than alpha-lipoic acid, cilostazol or cytidine triphosphate in short-term improvement of clinical and nerve test findings. All these findings require confirmation in larger studies before they can be accepted as definite. Vitamin B is generally well-tolerated with only a few reports of mild side effects.
