Research in the past has shown various B vitamins to reduce pain. Vitamins B1, B6 and B12 have been shown to reduce pain from nociceptors. Nociceptors are nerves that respond to damage in the body. Things like fractures, bruises, inflammation, burns etc. stimulate nociceptors. One study, presented to the American Physiological Society in April 2003, showed that sensory neurons in the spinal cord stimulated by nociceptors (carriers of noxious stimuli) were suppressed by certain B vitamins.
This recent study shows that the combination of vitamins B1, B6 and B12 can reduce pain that is triggered by an injury that involves actual damage to the nervous system (neuropathic pain). In mice, vitamins B1, B6 and B12 reduced the response to pain. The level of pain was determined by measuring foot withdrawal after heat stimulation to the rear paw. The inhibition of the pain paralleled to the amount of B vitamin given. Other studies have shown that B vitamins can reduce the pain from neuropathy.
It is worth noting here that eating refined sugar and other refined carbohydrates like white bread and noodles deplete B vitamins. Avoiding refined food while in pain may be a good strategy.