The clinical manifestations of copper deficiency can be similar to deficiency of which micronutrient?

• A. Vitamin B12
• B. Manganese
• C. Vitamin E
• D. Zinc

Answer: (A)

Copper deficiency can affect the nervous system in a way that mirrors what happens with vitamin B12 deficiency, especially causing sensory ataxia, paresthesias, and signs of myelopathy. Copper is needed for enzymes that help maintain myelin and for proper iron metabolism; when copper is lacking, demyelination in the spinal cord and peripheral nerves can produce neurologic symptoms similar to B12 deficiency. Hematologically, copper deficiency can also cause anemia from impaired iron utilization, which can be mistaken for the anemia seen with B12 deficiency.

To differentiate, B12 deficiency typically shows macrocytic anemia with low B12 levels and elevated methylmalonic acid and homocysteine, whereas copper deficiency may present with normocytic/microcytic anemia and responds to copper repletion. Other deficiencies like zinc excess can cause copper deficiency, but zinc deficiency itself does not produce the same neurologic profile as B12 deficiency, and vitamin E deficiency, while it can cause neuropathy, is less associated with the systemic iron-related features seen with copper deficiency.