Chromium.

Copper, a trace element that is essential for the human body. Copper is needed to absorb and utilize iron in the body. Copper is a part of enzymes, essentially proteins that assist biochemical reactions in cells.

Zinc is a metallic chemical element and an essential trace element, whereby only two to four grams of Zinc are found in the human body. There are several biological roles that Zinc plays in humans, including the metabolism of RNA and DNA, gene expression and the regulation of apoptosis. It is deemed vital for proper brain activity and essential in the learning process. It is also critical for the central nervous system, but is also found in muscle, bones, liver, kidneys, eyes and most prominently in the prostate. It is supplied to the body by the ingestion of red meats, particularly beef and lamb, but can also be found in seeds, including sesame and mustard, wheat, beans, whole grains, sunflower seeds and nuts, including almonds.