Zinc
An essential trace mineral involved in immune function, wound healing, DNA synthesis, and over 100 enzymatic processes.
Optimal Range
80-120 μg/dL (optimal)
Risk-Stratified Targets
| Population / Context | Target |
|---|---|
| Optimal | 80–120 μg/dL |
| Adequate | 60–80 μg/dL |
| Low (immune and metabolic consequences) | < 60 μg/dL |
Why It Matters
Zinc deficiency impairs immune function, slows wound healing, and accelerates thymic involution (immune aging). It is commonly depleted by stress, aging, and plant-heavy diets.
Understanding Zinc
Zinc is an essential trace mineral that serves as a cofactor for over 300 enzymes and plays structural roles in thousands of proteins. It is critical for immune cell development and function (particularly T-cell and natural killer cell activity), wound healing, taste and smell perception, DNA synthesis and repair, and testosterone production.
Zinc deficiency is remarkably common, particularly in older adults, vegetarians/vegans (phytates in grains and legumes inhibit zinc absorption), athletes (zinc is lost in sweat), and people under chronic stress. One of the most consequential effects of zinc deficiency is accelerated thymic involution — the age-related shrinking of the thymus gland that produces T-cells. This contributes directly to immunosenescence (immune aging), reducing the body's ability to fight infections and cancer.
Serum zinc testing has limitations — it represents only about 0.1% of total body zinc and can fluctuate with recent meals, time of day, and acute inflammation (zinc drops during the acute-phase response). Despite these limitations, it remains the most widely available and practical test. Supplementation with 15–30 mg of elemental zinc daily (as zinc picolinate, citrate, or glycinate) is generally safe, though long-term supplementation above 40 mg/day can deplete copper and should be accompanied by copper supplementation.