Niacin deficiency alone does not always cause pellagra

• Because Pellagra is a multi factorial disease.

1. Pellagra is primarily associated with a lack of niacin (vitamin B3) but can also arise due to inadequate intake of tryptophan, an amino acid the body converts into niacin.
2. Additionally, conditions that impair absorption, such as chronic alcoholism, gastrointestinal diseases, or certain medications, can contribute to pellagra.
3. Diets low in both niacin and tryptophan, such as those heavily reliant on corn without proper preparation, increase the risk.

• Thus, while niacin deficiency is a key factor, other nutritional and metabolic issues also play a role.

• Niacin deficiency alone cannot cause pellagra because the body can also synthesize niacin from the amino acid tryptophan.
• even if dietary niacin is low, adequate tryptophan intake can prevent pellagra.
• therefore, a deficiency in both niacin and tryptophan is necessary for the development of the disease.
• Eg, Diets high in corn, which is low in both niacin and readily available tryptophan, are often associated with pellagra because the body cannot efficiently convert the bound niacin in corn.