If tryptophan metabolism is impaired within intestinal cells, which consequence affecting nicotinamide production is most likely?

💡 Explanation

Intestinal cells convert tryptophan into nicotinamide (a precursor to NAD+/NADP+). Impaired tryptophan metabolism reduces the substrate available for nicotinamide synthesis, thereby lowering NAD+/NADP+ production because nicotinamide biosynthesis is limited by substrate availability; therefore, reduced NAD+/NADP+ biosynthesis occurs rather than other unrelated metabolic changes.

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