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.
