ROSH Gastrointestinal Practice Exam

Which vitamin deficiency leads to a triad of dermatitis, diarrhea, and dementia?

1. Ascorbic acid

2. Niacin

3. Pyridoxine

4. Thiamine

The correct answer is: Niacin

The triad of dermatitis, diarrhea, and dementia is characteristic of niacin deficiency, also known as pellagra. Niacin plays a crucial role in energy metabolism and the synthesis of certain hormones. Its deficiency can arise from insufficient dietary intake or from conditions that affect nutrient absorption, such as chronic alcoholism or malabsorption syndromes. Dermatitis associated with niacin deficiency typically presents as a photosensitive rash, often affecting areas of the skin that are exposed to sunlight. The diarrhea can be frequent and watery, leading to further complications related to dehydration and nutrient loss. The dementia or cognitive decline can manifest as confusion, disorientation, or other neurological symptoms, reflecting the vital role niacin plays in brain health and function. These three symptoms together form a distinctive clinical picture that helps healthcare professionals recognize niacin deficiency early and address it appropriately, often through dietary adjustments or supplementation.