What is it?
An trace mineral essential for immune function; healthy skin, eyes and nails; mental alertness; production of stress hormones, insulin and sex hormones.
What does it do?
Fights infection and heals wounds: A review of 18 studies, involving almost 1,800 participants, found zinc reduced the duration of the common cold when taken within 24 hours of symptom onset.
Improves skin, hair and nails: It may also help improve adult acne, according to a Swedish study.
Boosts libido: It can also improve sexual performance according to a study in the Journal of Human Reproductive Sciences.
Helps prevent type 2 diabetes: According to many studies, adequate intake can prevent insulin resistance, a form of pre-diabetes.
Controls stress hormones: In one study, just 25-50mg of zinc prompted a marked fall in cortisol in healthy volunteers who had undergone an extreme exercise stress test.
Improves fertility: Adequate levels help regulate ovulation and maturation of eggs.
When do I need it?
Throughout life. As zinc affects taste and smell, check your levels by putting 1-2 teaspoons of zinc sulfate in a glass and sip it. If it tastes like water, you are moderately deficient in zinc; if it tastes disgusting with a metallic taste, your levels are adequate.
How do I get it?
Eat: Good sources of zinc include lean red meat, liver, shellfish (especially oysters), egg yolks, dairy products, wholegrain cereals and pulses.
Take: a supplement of no more than 25mg a day. Combine with vitamin C for greater protection against colds.
Be careful if…
Avoid if you have liver damage or an intestinal disorder. High doses upset absorption of some minerals and vitamins.