The B group of vitamins play an important role in energy production in human metabolism (ever seen the claims on a cereal box?). That is because the B vitamins act as cofactors to enzymes that regulate the metabolic pathways glycolysis and the citric acid cycle. These pathways are the primary energy producing pathways in the body. However, a number of the B vitamins have other roles in the body. One such role is that of vitamin B6 in the relief of pain.
Vitamin B6 is also called pyridoxine. Following digestion it is absorbed and converted to its active metabolite, pyridoxal phosphate. Pyridoxal phosphate is able to interact with a number of enzymes because it is required as a cofactor. Some of these enzymes are thought to be involved in pathways that inhibit and reduce pain. Therefore higher intakes of vitamin B6 may facilitate these pathways and increase the release of pain relieving chemicals.
Gamma aminobutyric acid (GABA) is an amino acid neurotransmitter. It is used as a signal in the brain to inhibit the transmission of information. When pain signals are sent within the brain, GABA in able to quieten the signals by inhibiting the transfer of the stimulatory neurotransmitters. In this way, GABA can modulate pain and reduce its perception in the brain. Vitamin B6 is required in the synthesis of GABA and high intakes may thus having a pain relieving effect.
Like GABA, serotonin is an inhibitory neurotransmitter. This means that it can also inhibit the transfer of pain signals in the brain and favourably modulate the perception of pain. However, chronic pain can deplete the brain of serotonin through this process. Because serotonin is needed to maintain mood, chronic pain can cause depression. Taking vitamin B6 may boost serotonin production, and thus inhibit pain and prevent its associated depression.
Supplements or food?
The recommended amount of vitamin B6 for pain relief is between 50 to 150 mg per day. A number of foods such as whole grains, liver, red meat, eggs and legumes are good sources of vitamin B6. However, it is unlikely that even 50 mg of vitamin B6 could be consumed in a healthy balanced diet. Supplements are therefore recommended. Supplements also hold the advantage that a consistent intake can be taken, something that is not possible to judge from foods.