What is the effect of hemodialysis on copper balance?

• A. Copper losses are increased during hemodialysis
• B. Copper absorption increases during dialysis
• C. Copper levels rise due to plasma-to-dietary copper shift
• D. Copper status is unchanged by dialysis

Answer: (A)

Hemodialysis can remove certain trace elements from the blood into the dialysate, so copper balance can be negative after a session. Most copper in blood is bound to large proteins like ceruloplasmin, which are not filtered by the dialyzer, but a small pool of copper that is free or loosely bound can diffuse across the dialysis membrane into the dialysate. Because dialysate typically has little to no copper, this diffusion creates a net copper loss during each treatment. Over time, repeated sessions can lead to copper depletion unless dietary intake or supplementation compensates. The other ideas don’t fit this mechanism: absorption isn’t driven by dialysis, a plasma-to-dietary copper shift isn’t how dialysis impacts copper, and dialysis does change copper status rather than leaving it unchanged.