Question:easy
A patient on a maize diet presented with diarrhea, dementia and dysentry. Which vitamin deficiency is responsible for the features?
A patient on a maize diet presented with diarrhea, dementia and dysentry. Which vitamin deficiency is responsible for the features?
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Remember the classic 4 Ds of the deficiency disease associated with a maize-heavy diet and think which B vitamin is derived from tryptophan.
Updated On: Jun 23, 2026
- Niacin
- Thiamine
- Riboflavin
- Pyridoxine
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The Correct Option is A
Solution and Explanation
Pellagra -- Niacin (Vitamin B3) Deficiency:
Why maize causes it:
Maize is low in tryptophan, the essential amino acid used to synthesize niacin endogenously ($60\,mg$ tryptophan $= 1\,mg$ niacin). Additionally, niacin in maize exists as niacytin, a bound form that is not bioavailable. Populations dependent on maize develop niacin deficiency.
Classic presentation -- the 4 Ds:
1. Dermatitis: Photosensitive skin rash (Casal's necklace around neck)
2. Diarrhea: GI mucosal involvement
3. Dementia: Neuropsychiatric changes, confusion
4. Death: If untreated
Dysentery (bloody diarrhea) reflects severe GI mucosal damage in advanced pellagra.
Differential:
- Thiamine (B1): Beriberi, Wernicke-Korsakoff
- Riboflavin (B2): Cheilosis, angular stomatitis
- Pyridoxine (B6): Neuropathy, sideroblastic anemia
Answer: \[\boxed{\text{Niacin (Vitamin B3)}}\]
Why maize causes it:
Maize is low in tryptophan, the essential amino acid used to synthesize niacin endogenously ($60\,mg$ tryptophan $= 1\,mg$ niacin). Additionally, niacin in maize exists as niacytin, a bound form that is not bioavailable. Populations dependent on maize develop niacin deficiency.
Classic presentation -- the 4 Ds:
1. Dermatitis: Photosensitive skin rash (Casal's necklace around neck)
2. Diarrhea: GI mucosal involvement
3. Dementia: Neuropsychiatric changes, confusion
4. Death: If untreated
Dysentery (bloody diarrhea) reflects severe GI mucosal damage in advanced pellagra.
Differential:
- Thiamine (B1): Beriberi, Wernicke-Korsakoff
- Riboflavin (B2): Cheilosis, angular stomatitis
- Pyridoxine (B6): Neuropathy, sideroblastic anemia
Answer: \[\boxed{\text{Niacin (Vitamin B3)}}\]
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