Isolated Malabsorption of Vitamin B₁₂ Causing Megaloblastic Anemia and Hyperpigmentation in a Nigerian : Report of Case

A Nigerian patient is described with megaloblastic anemia due to vitamin B₁₂ deficiency. The deficiency resulted from malabsorption of the vitamin, but no other abnormal functioning of the gastrointestinal tract could be demonstrated. The patient did not have addisonian pernicious anemia. He had remarkable hyperpigmentation of the skin, especially of the palms of the hands. What is known of possible connections between megaloblastic anemias and melanin metabolism cannot explain this hyperpigmentation.