Pellagra is a deficiency of?

Appeared in: DSSSB -28 August 2019 (Shift-2)

Explanation

Pellagra is a systemic disease resulting from a severe deficiency of niacin (Vitamin B₃).
Nicotinic acid is a form of niacin, making it the correct answer.
The classic signs of pellagra are often remembered by the mnemonic 'the 3 Ds': Dermatitis (a photosensitive rash), Diarrhea, and Dementia.
Niacin is essential for forming the coenzymes NAD and NADP, which are critical for energy metabolism in all cells, especially in high-energy tissues like the skin, gut, and brain.

Option B: Deficiency of pantothenic acid (Vitamin B₅) is not associated with pellagra. It is very rare in humans.
Option C: Biotin (Vitamin B₇) deficiency does not cause pellagra. Its deficiency is also rare.
Option D: Pyridoxine (Vitamin B₆) deficiency is not the cause of pellagra.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Vitamin B3 (Niacin) Deficiency as background academic context rather than a clinical decision trigger.
Nurses should assess patients for risk factors of pellagra, including poor diet (especially corn-based), chronic alcoholism, and malabsorption disorders.
Assessment should include a thorough skin examination for photosensitive dermatitis, monitoring for gastrointestinal issues like diarrhea, and evaluating mental status for signs of confusion or depression.
Patient education is key, focusing on the importance of a balanced diet rich in niacin (found in meat, fish, legumes, and enriched grains) and tryptophan (an amino acid that can be converted to niacin).

How to Approach the Question

First, identify the keyword in the question stem, which is 'Pellagra'.
This is a factual recall question that tests your knowledge of vitamin deficiency diseases.
Recall the specific vitamin associated with pellagra.
Systematically evaluate the options. 'Nicotinic acid' is another name for niacin (Vitamin B₃).
Eliminate the other options by recalling the diseases associated with their deficiencies (e.g., B₆ with neuropathy, B₇ with dermatitis/alopecia from raw eggs).

Concept Tested & Keywords

QPdf6c1OAK39yGG4Vz3nv3

E6 Parks TextBook of Preventive & Social Medicine part 2 — Subpart A (pp 1-232 of 464) p. 154-156

E6 Medicine Davidson Principles Practice 24e p. 734-736

E6 Medicine Harrison 22e Part 2 p. 512-514

Practise the full DSSSB -28 August 2019 (Shift-2)

Attempt every question from this paper in a timed mock, then review the full solution for each one.