Severe deficiency of vitamin B6 is rare.
Studies have shown that thiamine is necessary for proper metabolism and function of vitamin B6. Therefore, alcoholics who are also deficient in thiamine due to low dietary intake are at highest risk of also suffering the effects of vitamin B6 deficiency.
Some studies have documented abnormal electroencephalograms (EEGs) in vitamin B6 deficiency. Other neurological symptoms that occur with severe deficiency are irritability, depression, and confusion. Other symptoms include glossitis (inflammation of the tongue), sores or ulcers in the mouth, and rhagades (cracks and ulcers) at the corners of the mouth.