Pellegra can cause all of the following except
**Core Concept**
Pellagra is a disease caused by a lack of niacin (vitamin B3) or tryptophan, an amino acid that the body uses to make niacin. It is characterized by the three D's: diarrhea, dermatitis, and dementia.
**Why the Correct Answer is Right**
Pellagra is a classic example of a disease caused by a nutritional deficiency. Niacin is crucial for the synthesis of NAD and NADP, which are essential for energy metabolism. The brain is particularly vulnerable to niacin deficiency, leading to the development of dementia. The skin manifestations of pellagra are due to the inability of the body to synthesize NAD, which is necessary for the metabolism of fatty acids and cholesterol. Diarrhea is caused by the impaired absorption of carbohydrates and fats.
**Why Each Wrong Option is Incorrect**
* **Option A:** Pellagra can indeed cause diarrhea, so this option is incorrect.
* **Option B:** Pellagra can cause dermatitis, which is a hallmark of the disease, so this option is incorrect.
* **Option C:** Pellagra can cause dementia, which is a result of the brain's inability to synthesize NAD, so this option is incorrect.
* **Option D:** Pellagra can cause a form of dermatitis known as "sunburn-like" lesions, but it is not typically associated with the development of cancer. This makes option D a plausible answer.
**Clinical Pearl / High-Yield Fact**
Pellagra can be prevented by consuming a diet rich in niacin or tryptophan, or by supplementing with niacin. The disease is often seen in populations that consume a diet high in corn, which is low in tryptophan.
**Correct Answer: D. Pellagra is not typically associated with the development of cancer.**