Zinc

Enzymes, DNA/protein, growth, immunity, wound healing, smell and taste.

Swiss reference value

Switzerland: depends on phytate intake; women about 7.5–12.7 mg/day, men 9.4–16.3 mg/day.

Good food sources

Oysters, meat, cheese, pumpkin/hemp seeds, legumes and whole grains; soaking/fermenting improves plant availability.

When intake or status is low

Poor appetite, infection susceptibility, delayed wound healing, loss of smell/taste and, when severe, impaired growth.

Long-term health connections

True deficiency can affect skin and hair; nonspecific hair loss alone does not prove it.

Skin, hair and nails

Hair loss, dermatitis and poor wound healing are possible but diagnostically nonspecific.

Who is more at risk

Malabsorption, chronic diarrhoea, alcohol dependence, bariatric surgery and poorly planned high-phytate diets.

How to assess it

Diet, risk factors and symptoms; serum zinc fluctuates and requires cautious interpretation.

Supplements: when to consider

Use in a targeted, time-limited way; consider copper with longer-term use.

Too much and safety

Excess zinc causes nausea and can lead to copper deficiency, anaemia and neurological problems.

International reference systems