Nutrition and Vitamin Deficiencies · USMLE Step 1

Deficiency of which vitamin can impair immune function and integrity of epithelial barriers, increasing susceptibility to infections?

  1. Vitamin A
  2. Vitamin B1
  3. Vitamin C
  4. Vitamin B3
Show answer and explanation

Correct answer: Vitamin A

Vitamin A is essential for maintenance of epithelial tissues and mucous membranes; deficiency compromises barrier integrity and impairs immune defenses, increasing infection risk.

Difficulty: Medium Question 17 of 21

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