What is Zinc?

Zinc is an essential trace mineral that the body cannot store in any large quantity, so a small amount has to come from food every day. It works as a structural or catalytic component in hundreds of enzymes, which is why it appears in discussions of immune function, DNA synthesis, and the condition of skin, hair and nails.

What does zinc do in the body?

Zinc plays several roles in the body:

• Contributes to the normal function of the immune system
• Contributes to normal DNA synthesis
• Contributes to the maintenance of normal skin, hair and nails
• Contributes to normal protein synthesis
• Contributes to the protection of cells from oxidative stress

These are descriptions of normal physiology. Taking in more than the body needs does not add to them.

Why does zinc need to come in every day?

Unlike iron, the body keeps no dedicated zinc store it can draw on when intake drops. Circulating zinc is small relative to what is bound up in muscle and bone, and those pools are not easily released. Intake therefore has to be reasonably steady rather than occasional.

How much zinc do you need?

The Thai Reference Daily Intake (Thai RDI) for zinc, for the general population aged 3 and over, is 11 mg a day. The US tolerable upper intake level for adults, published by the US Office of Dietary Supplements, is 40 mg a day from all sources combined. Higher amounts taken over long periods can interfere with copper absorption, which is why long-term high-dose use is not a self-managed decision.

Where does zinc come from in food?

Oysters are by a wide margin the densest source. Red meat and poultry supply most zinc in a typical mixed diet, with crab, shrimp, beans, chickpeas, nuts, pumpkin seeds, whole grains, dairy and eggs contributing the rest. Zinc from plant sources is absorbed less efficiently because phytate, present in legumes and whole grains, binds it. Soaking, sprouting and fermenting reduce phytate.

Who tends to fall short?

Vegetarian and vegan diets, older adults, and pregnancy and breastfeeding are the situations most often discussed. A qualified healthcare provider can assess an individual's zinc status properly.

What should you keep in mind?

High-dose iron or calcium and some medicines can affect zinc absorption in either direction.

Zinc is a small daily requirement rather than something to load up on. If you are pregnant, breastfeeding, or taking prescription medication, check with a doctor or pharmacist before taking supplements.