Niacin deficiency

Niacin deficiency refers to damage to material metabolism in poultry caused by simultaneous deficiency of niacin and tryptophan. This deficiency mainly manifests as pellagra symptoms; niacin is also called the anti-pellagra vitamin. Early manifestations in patients may be inconspicuous, often presenting with nonspecific symptoms such as loss of appetite, fatigue and weakness, weight loss, abdominal discomfort, indigestion, easy excitability, poor concentration, and insomnia. As the disease progresses, more typical symptoms may appear, occurring upon sunlight exposure in summer and autumn, and sometimes induced by radiation or physical skin damage.