Zinc
A trace element involved in over 300 enzymes, essential for immunity, wound healing, protein synthesis, fertility and taste.
Zinc is a “jack of all trades” mineral: immunity, wound healing, DNA and protein synthesis, cell division, fertility (sperm production), the sense of taste and smell, and skin health.
The original angle (immunity and taste): zinc is crucial for the immune system, and a deficiency weakens the body’s defences. This is why zinc lozenges, taken at the first symptoms, may slightly shorten a cold (a modest but documented effect).
A little-known sign of deficiency: a loss of taste and smell, or white spots on the nails. Zinc is essential for fast-renewing cells (taste buds, skin).
The plant bioavailability trap: zinc from plants (cereals, pulses) is poorly absorbed because of phytic acid, which binds it. Vegetarians and vegans therefore have higher needs (~50% more) and benefit from soaking, sprouting and fermenting, which release the zinc.
The zinc/copper balance: prolonged high-dose zinc supplementation can cause a copper deficiency (the two compete for absorption). Hence the importance of not over-supplementing with isolated zinc over the long term.
Sources: oysters (the absolute champions), red meat, pumpkin seeds, cashews, pulses (with proper preparation), cheese.
Zinc and stress: stress and intense exercise increase zinc losses. Athletes and stressed people may have higher needs.