Researcher’s also shown that substances such as vitamins C, fiber and bile in excessive amounts can decrease the efficiency of copper absorption. High intake of manganese also can interfere with copper absorption. Protein and fresh vegetable foods have been shown to improve copper absorption.
Copper levels are reduced if large amounts of zinc or vitamin C are consumed.
Supplementing diet with zinc can help rebalance the situation, but care must be taken to avoid taking too much zinc, which will cause a copper deficiency.
There was a hypothesis that an excess of zinc relative to copper may increase the risk factors for cardiovascular disease including elevated serum cholesterol and hypertension.
The consumption of high amount of fructose (fruit sugar) can make a copper deficiency significantly worse.
Copper relationship with other nutrients