Which substances will prevent absorption of zinc and copper in the diet?

• A. Sulfate, Iron, Nitrates
• B. Vitamin C, Calcium
• C. Chloride, Fluoride
• D. Zinc, Magnesium

Answer: (A)

The thing being tested is how dietary components can block mineral uptake by the gut. Zinc and copper share similar absorption pathways, so substances that compete for those pathways or form less soluble compounds in the intestine can reduce how much of these minerals are absorbed.

Iron is a well-known competitor for intestinal uptake. When iron is present in higher amounts, it competes with zinc and copper for the same transport systems and can indirectly promote mechanisms that limit zinc and copper absorption. Sulfate in the diet can contribute to forming less soluble mineral salts in the gut, making zinc and copper less available for absorption. Nitrates can alter the gut environment or form complexes with minerals that are less readily absorbed. Taken together, these dietary components can reduce absorption of both zinc and copper.

The other options contain substances that don’t consistently block both minerals together in typical diets—for example, vitamin C tends to enhance iron absorption, and calcium can interfere with zinc absorption but doesn’t reliably suppress copper, so they don’t fit as a combined inhibitor for zinc and copper.