Evidence of dietary copper and zinc deficiencies.

The mean daily amounts of copper and zinc found in hospital diets by atomic absorption spectrometry were 0.76 and 9.4 mg, respectively. Comparison of these diets with published data showed median daily amounts of copper and zinc to be 0.78 and 12.0 mg, respectively, for 20 diets made from conventional foods. These amounts of copper and zinc are less than the 2 mg of copper and 13 mg of zinc thought to be required daily by adults. Hospital diets and perhaps diets in general seem to be low in copper and zinc; the amounts of copper are lower than those of zinc in comparison with respective requirements. Common dietary amounts of these elements may cause health problems.