Vitamin B
6 deficiency is one of the most common nutritional deficiencies. Much of this is due to the fact that a lot of vitamin B
6 is lost during cooking and food processing. A U.S. Department of Agriculture study reported that 80 percent of Americans consume less than the recommended dietary allowance (RDA) for pyridoxine.(
2)
Adequate pyridoxine is important because it is involved in the production of hemoglobin in red blood cells and neurotransmitters like serotonin, which plays a part in regulating our moods and preventing depression.(3),(4) It is also involved in energy production in the body, as well as the metabolism of homocysteine, the amino acid that is a risk factor for atherosclerosis.(5),(6) When used with vitamin B12 and folic acid, studies have shown that it can decrease homocysteine levels.(7) Decreased vitamin B6 levels seemed to indicate a greater risk for coronary artery disease.(8) Dietary supplementation with the B-vitamins prevented hyperhomocysteinemia but did not prevent the development of vascular dysfunction or atherosclerotic lesions.(9)
Other studies involving hundreds of patients who had undergone successful coronary angioplasty have evaluated these individuals following six months of therapy on vitamin B6, vitamin B12 and folic acid, comparing the results to patients on placebo. After one year, the patients on the vitamin therapy had lower rates of related cardiovascular events including heart attacks and repeated angioplasty.(10),(11)
There is a wide range of clinical applications for pyridoxine. Patients with rheumatoid arthritis have also been found to be deficient in vitamin B6 and supplementation may be beneficial.(12) Asthmatics may experience fewer and less severe attacks when taking pyridoxine.(13) Studies have shown cognitive skills such as knowing, thinking, learning and judging can be impaired in older adults with low levels of certain B vitamins. Supplementation with folate, vitamin B12 and vitamin B6 has been effective in enhancing cognitive performance in older adults.(14) In fact, one study in older adults noted that subjects with low levels of vitamin B12 or folate had twice the risk of developing Alzheimer's disease.(15)
Pyridoxine is also an important treatment for pyridoxine-dependent epilepsy.(16),(17) It may even treat some symptoms of autism.(18) It may ease some of the nerve-related problems (neuropathies) that frequently develop in diabetic patients.(19) Vitamin B6, B12 and folic acid were effective in reducing migraine disability, severity and frequency.(20)
Pyridoxine has been used to support female health as well. Studies suggest that it can reduce the severity and frequency of vomiting episodes during pregnancy.(21) It may also ease PMS symptoms.
Pyridoxine is required for the metabolism of monosodium glutamate (MSG). People who are sensitive to this common food additive are said to suffer from "Chinese restaurant syndrome." In these individuals, supplementation with vitamin B6 often prevents or substantially reduces the severity of symptoms when they ingest MSG.(22),(23)