Vitamin B6 (pyridoxine) deficiency

Vitamin B6 (pyridoxine) deficiency

Definition

Deficiency of pyridoxine is rarely a primary disorder, but it does occur as a secondary disorder.

Aetiology

Important sources of Vitamin B6 are similar to those of the other B vitamins: liver, meat, whole grain cereals, vegetables and nuts. Deficiency may occur with malabsorption such as coeliac disease, dietary lack in alcoholism and drug toxicity especially isoniazid.

Pathophysiology

Pyridoxine is important in the metabolism of amino acids, especially tryptophan to nicotinic acid. In some rare metabolic disorders, pyridoxine deficiency is associated with infantile convulsions and sideroblastic anaemia.

Clinical features

Marginal deficiency may cause stomatitis, glossitis, dry lips, irritability and confusion. Deficiency causes mental confusion, glossitis, dry skin lesions and peripheral neuropathy.

Management

Oral replacement; however, high doses may cause neurotoxicity.