Peripheral neuropathy is associated with lowered plasma vitamin B12 levels

Objectives:
Peripheral neuropathy (PN) is common in patients with diseases that are in turn associated with deficiency of the B-vitamins, and vitamin treatment has shown mixed results. Therefore, this review article has been conducted.

Does a low vitamin B level increase the risk of peripheral neuropathy?

Study design:
This review article included 46 observational studies and 7 interventional studies.

Results and conclusions:
The investigators found the presence of peripheral neuropathy was significantly associated with lowered B12 levels [1.51, 95% CI = 1.23 to 1.84, n = 34, I2 = 43.3%, p = 0.003].

The investigators found the presence of peripheral neuropathy was significantly associated with elevated methylmalonic acid levels [2.53, 95% CI = 1.39 to 4.60, n = 9, I2 = 63.8%, p = 0.005].

The investigators found the presence of peripheral neuropathy was significantly associated with elevated homocysteine levels [3.48, 95% CI = 2.01 to 6.04, n = 15, I2 = 70.6%, p 0.001].

The investigators found treatment with vitamin B1 was associated with a significant improvement in symptoms of peripheral neuropathy [5.34, 95% CI = 1.87 to 15.19, n = 3, I2 = 64.6%, p = 0.059].

The investigators found B12 treatment (vs. the comparators) showed a non-significant association with symptom improvement [1.36, 95% CI = 0.66 to 2.79, n = 4, I2 = 28.9%].

The investigators found analysis of 7 trials combined showed a non-significant higher odds ratio for improvement under treatment with the B-vitamins [2.58, 95% CI = 0.98 to 6.79, I2 = 80.0%, p 0.001].

The investigators concluded peripheral neuropathy is associated with lowered plasma vitamin B12 and elevated methylmalonic acid and homocysteine levels. Well-designed studies, especially in non-diabetes peripheral neuropathy, are needed.

Original title:
Association between neuropathy and B-vitamins: A systematic review and meta-analysis by Stein J, Geisel J and Obeid R.

Link:
https://pubmed.ncbi.nlm.nih.gov/33619867/

Additional information of El Mondo:
Find here more information/studies about review article/significant, vitamin B1 y B12 and chronic diseases.

Peripheral neuropathy refers to the conditions that result when nerves that carry messages to and from the brain and spinal cord from and to the rest of the body are damaged or diseased.

Increased methylmalonic acid levels are a sensitive indicator of mild vitamin B12 deficiency.