A patient exhibits chronic fatigue and pale skin after gastric bypass surgery. Which mechanism explains why these symptoms occur despite adequate dietary iron intake and supplemental vitamin B12?

💡 Explanation

Impaired intrinsic factor production causes reduced vitamin B12 absorption, leading to megaloblastic anemia because the gastric bypass altered the site of intrinsic factor secretion. Therefore, fatigue and pale skin result, rather than increased red cell production or enhanced iron absorption.

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