Zinc

What it does

Zinc is a component or activator of hundreds of enzymes and is essential for making DNA and proteins, so it is central to growth, repair and the creation of new cells. This is why it matters so much during childhood, adolescence, pregnancy and wound healing — any time the body is building tissue at pace. A shortage slows growth in children and impairs healing at any age.

Zinc is crucial for a healthy immune system. It is needed for the development and normal function of the white blood cells that fight infection, and a deficiency leaves people more prone to illness. It also supports the senses of taste and smell, keeps skin healthy, and is involved in male reproductive health and normal fertility, which is why deficiency can show up as skin problems, hair loss and a reduced sense of taste.

The body has no large store of zinc, so a regular intake is needed. It is found in meat, shellfish (oysters are especially rich), dairy, wholegrains, nuts and pulses. Zinc from animal foods is better absorbed than that from plants, where compounds called phytates can bind it — something worth knowing for people on mainly plant-based diets. Very high supplement doses can interfere with the absorption of copper, so more is not better.