Zinc

FoundationalImmuneHormonesSkin

Critical for immune function, testosterone, wound healing, taste, smell, and skin. One of the most consistently under-consumed minerals, especially in plant-heavy diets.

EvidenceStrong

Strong for immune function (cold duration reduction, T-cell support), wound healing, acne, taste recovery in deficient people, and male fertility. Modest testosterone elevation in deficient men (not in already-replete men). Effects on immunity: days. Acne, skin: 4–8 weeks. Testosterone: 6–12 weeks.

Zinc is a cofactor for over 300 enzymes and structurally embedded in over a thousand proteins (zinc fingers in DNA-binding transcription factors). It runs immune cell production and function, T-cell maturation, wound healing, sperm production, taste/smell perception, and is required for testosterone synthesis. Plant foods contain zinc but it's largely bound up by phytates — vegetarians and vegans typically absorb 30–50% less than omnivores. Deficiency symptoms (poor immunity, slow healing, loss of taste, hair loss, acne, low testosterone) are common and easily reversed.

Form
Zinc picolinate or bisglycinate — well-absorbed, well-tolerated. Citrate is fine too. Zinc carnosine (Pepzin GI) is specifically for gut healing. Lozenges (acetate or gluconate) for acute viral illness — works at the throat tissue, must dissolve slowly. Avoid oxide and sulfate (poorly absorbed, GI upset).
Dose
15–30 mg/day for general maintenance. 30–50 mg/day for immune support or wound healing. Don't exceed 40 mg/day chronically without monitoring — high zinc displaces copper.
Timing
With food (empty-stomach zinc often causes nausea). PM is common — zinc supports the GH and testosterone pulses that happen overnight.
Schedule
Daily. If running high doses (>40 mg) for more than a few weeks, supplement 1–2 mg copper to avoid imbalance, or cycle.
Side effects
Nausea on empty stomach. Metallic taste. Copper deficiency at high chronic doses (anemia, neuropathy). Lozenges can numb the throat or cause oral irritation.
Interactions
Reduces absorption of: tetracyclines, fluoroquinolones, bisphosphonates, penicillamine, copper, iron — separate by 2 hours. Thiazide diuretics increase zinc loss.
Contraindications
None at sensible doses. Long-term very high doses (>100 mg/day) are immunosuppressive and depletive of copper — avoid.
Lab markers
Serum zinc (limited utility — homeostatically regulated). Plasma zinc with food-restriction protocol. Copper-to-zinc ratio (more useful than either alone). Alkaline phosphatase (zinc-dependent enzyme) low when zinc low.
Food sources
Oysters (extraordinary — single oyster can deliver a full RDA), red meat (beef especially), lamb, pumpkin seeds, hemp seeds, cashews, chickpeas, lentils, oats. Animal-source zinc absorbs significantly better than plant-source.

Pairs with

Vitamin A (zinc is required to mobilise A from liver). Vitamin C and elderberry (immune stack). Copper (balance — 10–15:1 zinc:copper ratio). Magnesium and vitamin B6 (the ZMA stack for sleep and recovery).