Which statement about zinc and copper interaction in enteral nutrition is true?

Which statement about zinc and copper interaction in enteral nutrition is true?

• A. Zinc can compete with copper for absorption
• B. Copper can compete with zinc for absorption
• C. They do not interact
• D. Zinc and copper absorption are both enhanced by vitamin C

Answer: (A)

Zinc and copper compete for absorption in the small intestine. When zinc intake is high, enterocytes produce more metallothionein, a protein that binds metals and traps them in the mucosa. Metallothionein has a relatively strong affinity for copper, so copper absorption is hindered while zinc is absorbed, leading to reduced copper availability systemically. This interaction is especially important in enteral nutrition, where high zinc doses can contribute to copper deficiency if copper isn’t adequately provided. That’s why the statement that zinc can compete with copper for absorption is true. Note: copper and zinc don’t have a separate, independent enhancement from vitamin C; vitamin C mainly affects iron absorption and doesn’t meaningfully boost zinc and copper absorption.

Zinc and copper compete for absorption in the small intestine. When zinc intake is high, enterocytes produce more metallothionein, a protein that binds metals and traps them in the mucosa. Metallothionein has a relatively strong affinity for copper, so copper absorption is hindered while zinc is absorbed, leading to reduced copper availability systemically. This interaction is especially important in enteral nutrition, where high zinc doses can contribute to copper deficiency if copper isn’t adequately provided. That’s why the statement that zinc can compete with copper for absorption is true.

Note: copper and zinc don’t have a separate, independent enhancement from vitamin C; vitamin C mainly affects iron absorption and doesn’t meaningfully boost zinc and copper absorption.