Niacin Deficiency

Distinctive dark red rash appears on the hands, feet, calves, neck, and face, and the tongue and mouth turn dark red.

Many people with niacin deficiency also have deficiencies of protein, riboflavin (a B vitamin), and vitamin B6.

Pellagra develops only if diet is deficient in niacin & tryptophan (body can convert tryptophan to niacin).

Affects the skin, digestive tract, & brain.

Also develops in:

Hartnup disease (absorption of tryptophan is impaired), & Carcinoid syndrome (tryptophan is not converted to niacin).

Alcoholism & isoniazid can lead to a deficiency of niacin.

The diagnosis of niacin deficiency is based on the diet history and symptoms. Measuring a by-product of niacin in urine can help establish the diagnosis, but this test is not always available. The diagnosis is confirmed if niacin relieves symptoms.

Treatment: Nicotinamide, unlike nicotinic acid, does not cause flushing, itching, burning, or tingling sensations.