Background

• Vitamin B6 (pyridoxine) is required for the synthesis of the neurotransmitters serotonin and norepinephrine and for myelin formation. Pyridoxine deficiency in adults principally affects the peripheral nerves, skin, mucous membranes, and the circulatory (blood cell) system. In children, the central nervous system (CNS) is also affected. Deficiency can occur in people with uremia, alcoholism, cirrhosis, hyperthyroidism, malabsorption syndromes, and congestive heart failure (CHF), and in those taking certain medications. Mild deficiency of vitamin B6 is common.
• Major sources of vitamin B6 include cereal grains, legumes, vegetables (carrots, spinach, peas, and potatoes), milk, cheese, eggs, fish, liver, meat, and flour. Pyridoxine is frequently used in combination with other B vitamins in vitamin B complex formulations.
• High homocysteine levels in the blood (hyperhomocysteinemia) have been suggested as being a risk factor for cardiovascular disease. Taking pyridoxine supplements in combination with other B vitamins (folic acid and vitamin B12) has been shown to be effective for lowering homocysteine levels. It is not clear if lowering homocysteine levels results in reduced cardiovascular morbidity and mortality.
• Vitamin B6 is also used to treat hereditary sideroblastic anemia, vitamin B6 deficiency, and vitamin B6-dependent seizures in newborns, and to prevent adverse effects in people taking the medication cycloserine. Evidence in support of other uses is inconclusive.

References

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