CLINICAL TRIALS REVIEWING THE ROLE OF VITAMIN B12 IN NEUROPATHY
In this clinical study, taking methylcobalamin for up to 4 months seems to improve pain and autonomic symptoms in patients with diabetic peripheral neuropathy.
Another study of 108 patients taking mecobalamin (Vitamin B12) intramuscularly for 4 weeks then 500 mcg orally three times daily for 8 weeks, shows that pain and numbness of limbs were improved by 73% and 75% in the Vitamin B12 group, which were much higher than those in the controls (36% and 45% respectively).
In a different study, 42 patients who had long-standing diabetes (mean duration of 12 years) with symptoms of neuropathy were divided into two groups of 21 patients. Each group was given either methylcobalamin or placebo. The 21 patients receiving methylcobalamin showed significant improvement in nerve pain and cramps. No adverse effects were observed. The mechanism of action is due partly to improvement in motor and sensory function, possibly by promoting myelin and axonal phospholipid synthesis.