What amino acid is conditionally essential during wound healing?

• A. Arginine
• B. Leucine
• C. Lysine
• D. Methionine

Answer: (A)

During wound healing, the body’s demand for substrates that drive tissue repair, immune defense, and blood flow increases. Arginine stands out because it is a key precursor for nitric oxide, which improves blood flow to the wound and supports immune cell function. It is also converted to ornithine and then to polyamines, which help cell proliferation and collagen synthesis—both essential for repairing tissue. When repair needs surge, the body may not meet them with synthesis alone, so dietary arginine becomes necessary. The other amino acids listed are essential in general, but they don’t become conditionally essential specifically due to wound healing in the same way arginine does.