Which ONE of the following does not impair healing of a wound?

The answer is D. Wounds in areas of poor vascularity (i.e., the skin of the shin) heal very slowly compared with wounds of the face and scalp. Tissue hypoxia following severe injury results in poor healing (E). Galactosamine and vitamin C (A, B) are essential for the repair of ground substances and collagen including type IV (basement membrane) collagen. Excessive glucocorticoids (C) are associated with poor healing, and this may be seen in patients on long-term steroid therapy.