Pellagra is caused by deficiency of which vitamin?

Pellagra is caused by deficiency of which vitamin?

• A. Vitamin B3
• B. Vitamin B6
• C. Vitamin B2
• D. Vitamin B12

Answer: (A)

Pellagra arises from a deficiency of niacin, which is vitamin B3. Niacin is needed to form the coenzymes NAD and NADP, essential for numerous oxidation-reduction reactions in energy metabolism. When niacin is low, or when tryptophan (a niacin precursor) isn’t adequately available or converted, tissues can't perform these reactions effectively. This leads to the classic symptoms: a dermatitis that worsens in sun-exposed areas, persistent diarrhea, and cognitive or neurological changes that can progress to dementia. If not corrected, it can be fatal. Other B vitamins have different roles: for example, B6 supports amino acid metabolism and neurotransmitter synthesis, B2 (riboflavin) is part of FAD and FMN for redox reactions, and B12 is crucial for DNA synthesis and nerve health. Their deficiencies produce different clinical pictures rather than pellagra.

Pellagra arises from a deficiency of niacin, which is vitamin B3. Niacin is needed to form the coenzymes NAD and NADP, essential for numerous oxidation-reduction reactions in energy metabolism. When niacin is low, or when tryptophan (a niacin precursor) isn’t adequately available or converted, tissues can't perform these reactions effectively. This leads to the classic symptoms: a dermatitis that worsens in sun-exposed areas, persistent diarrhea, and cognitive or neurological changes that can progress to dementia. If not corrected, it can be fatal.

Other B vitamins have different roles: for example, B6 supports amino acid metabolism and neurotransmitter synthesis, B2 (riboflavin) is part of FAD and FMN for redox reactions, and B12 is crucial for DNA synthesis and nerve health. Their deficiencies produce different clinical pictures rather than pellagra.