Zinc Tablets: Effects, Dosage and Deficiency

What Are Zinc Tablets?

Zinc tablets are oral dietary supplements that deliver the essential trace element zinc in a concentrated form. Zinc is a vital mineral that the body cannot produce on its own and must therefore be obtained regularly through food or supplements. Zinc tablets are used to correct a zinc deficiency or to meet the increased needs of certain population groups.

Biological Functions of Zinc

Zinc is involved in more than 300 enzymatic reactions in the human body. It performs numerous vital functions:

• Immune system: Zinc strengthens the immune defenses and supports the formation and activity of immune cells.
• Wound healing: Zinc promotes cell regeneration and is essential for normal wound healing.
• Protein synthesis and cell division: Zinc is necessary for the growth, development, and repair of body tissues.
• Skin, hair, and nails: Zinc contributes to maintaining normal skin, hair, and nail health.
• Hormonal balance: Zinc plays an important role in the production of testosterone and other hormones.
• Antioxidant protection: Zinc protects cells from oxidative stress.
• Taste and smell: Zinc is required for the normal perception of taste and smell.

Dietary Sources of Zinc

Zinc is found in many foods. Particularly rich sources of zinc include:

• Meat (especially beef and pork)
• Seafood (particularly oysters)
• Legumes (lentils, chickpeas, beans)
• Nuts and seeds (pumpkin seeds, cashews)
• Whole grain products
• Dairy products and eggs

Plant-based zinc sources often contain phytic acid, which can inhibit zinc absorption in the intestine. This is why people following vegetarian or vegan diets face an increased risk of zinc deficiency.

Recommended Daily Intake

The recommended daily zinc intake varies by age, sex, and life stage. According to the World Health Organization (WHO) and the European Food Safety Authority (EFSA), the following reference values apply:

• Adult men: 11–16 mg per day
• Adult women: 7–10 mg per day
• Pregnant women: 7–13 mg per day
• Breastfeeding women: 11–13 mg per day
• Children and adolescents: 3–11 mg per day (depending on age)

Exact recommendations also depend on dietary composition, as plant-based diets reduce the bioavailability of zinc.

Zinc Deficiency: Causes and Symptoms

A zinc deficiency can have various causes, including insufficient intake, increased requirements, or reduced intestinal absorption. Typical symptoms include:

• Weakened immune system and frequent infections
• Delayed wound healing
• Hair loss
• Skin changes (dry, flaky skin, acne)
• Impaired taste and smell
• Growth delays in children
• Fatigue and exhaustion
• Hormonal imbalances

Groups at risk for zinc deficiency include older adults, pregnant and breastfeeding women, vegetarians and vegans, people with chronic inflammatory bowel diseases, and individuals with alcohol dependence.

Usage and Dosage of Zinc Tablets

Zinc tablets are available in various dosages and compound forms, such as zinc gluconate, zinc citrate, zinc sulfate, or zinc bisglycinate. The bioavailability -- the amount of zinc actually absorbed by the body -- differs depending on the compound form.

• For prevention of deficiency, low-dose preparations (5–10 mg zinc daily) are often sufficient.
• For treatment of confirmed deficiency, higher doses (15–25 mg daily) are commonly used, ideally in consultation with a healthcare provider.
• Zinc tablets are ideally taken on an empty stomach or between meals to optimize absorption. If stomach discomfort occurs, they can be taken with food.
• Simultaneous intake with calcium or iron may reduce zinc absorption and should be staggered by at least 2 hours.

Side Effects and Risks

Excessive intake of zinc tablets can cause unwanted effects:

• Nausea, vomiting, and stomach discomfort (especially when taken on an empty stomach)
• Copper deficiency with long-term high zinc intake, as zinc and copper compete for the same transport proteins
• Reduced absorption of other minerals

The European Food Safety Authority (EFSA) recommends a tolerable upper intake level of 25 mg of zinc per day for adults from dietary supplements. Long-term overdosing should be strictly avoided.

Interactions

Zinc tablets can interact with various medications and nutrients:

• Antibiotics (e.g., tetracyclines, fluoroquinolones): Zinc can reduce the absorption of these medications. A time gap of at least 2 hours is recommended.
• Copper: High zinc intake can inhibit copper absorption.
• Iron and calcium: Can reduce zinc absorption when taken simultaneously.

References

1. World Health Organization (WHO): Trace Elements in Human Nutrition and Health. Geneva: WHO Press (1996).
2. European Food Safety Authority (EFSA): Scientific Opinion on Dietary Reference Values for Zinc. EFSA Journal 12(10):3844 (2014).
3. Prasad, A.S.: Zinc in Human Health: Effect of Zinc on Immune Cells. Molecular Medicine, 14(5-6):353-357 (2008).