Vitamin B6 deficiency (pyridoxine) is a condition of the lack of pyridoxine in the body.
Pyridoxine, also known as vitamin B6, is a vitamin found in food and used as a dietary supplement. Pyridoxine is one of 8 vitamins of the group B.
This vitamin is an essential cofactor in various transamination, decarboxylation, glycogen hydrolysis, and synthesis pathways involving carbohydrate, sphingolipid, amino acid, heme, and neurotransmitter metabolism (dopamine, serotonin, epinephrine, norepinephrine, glycine, glutamate, and GABA) . Therefore the deficiency of this vitamin causes impairment of the nervous and circulatory systems, and causes skin changes.
Vitamin B6 is found in:
whole grains and cereals;
nuts and seeds;
legumes and beans (chickpeas);
The recommended daily allowance depends on the age and gender:
Newborn–6 months: 0.3 milligrams;
Children 1–8 years: 0.5- 0.6 milligrams;
Children 4–16 years: 0.6- 1.0 milligrams;
Boys 14–18 years: 1.2- 1.3 milligrams;
Men and women 19–50 years: 1.3 milligrams;
Men 51 years and older: 1.7 milligrams;
Women 51 years and older: 1.5 milligrams;
Pregnant women: 1.9 milligrams;
Breastfeeding women: 2.0 milligrams;
Causes and risk factors
The elderly are at risk of developing pyridoxine deficiency.
Some medical conditions which may increase the risk of pyridoxine deficiency, including: severe malnutrition, sickle cell disease, inflammatory conditions, rheumatoid arthritis, celiac disease, kidney and liver diseases, catabolic state etc.
Some medical procedures may also contribute to the development of pyridoxine deficiency: hemodialysis and peritoneal dialysis, phototherapy for hyperbilirubinemia.
Intake of cycloserine, hydralazine, isoniazid, D-penicillamine and pyrazinamide interferes with pyridoxine and causes pyridoxine deficiency.
Excessive alcohol ingestion (except for pyridoxine-supplemented beer), tobacco smoking and severe malnutrition as well as the poor diet of the pregnant women lead to the deficiency of vitamin B6.
Pyridoxine-dependent neonatal seizures is an inherited condition as autosomal-recessive pattern.
See also: Vitamin F deficiency
The symptoms of pyridoxine deficiency include:
Weakness and fatigue;
Glossitis and cheilosis;
Early myocardial infarction and stroke;
Bilateral limb numbness and burning sensation;
Impaired vibration perception;
Confusion and irritability;
Levels of pyridoxine hydrochloride supplementation vary in different medical conditions from 2,5 mg/day (peritoneal dialysis) up to 600 mg/day (in case of sideroblastic anemia).
To prevent the deficiency of pyridoxine the vitamin should be administered, if the person is using isoniazid (30-450 mg/d) and penicillamine (100 mg/d).