Zinc

Zinc is one of the most versatile minerals in the body: it takes part in the activity of more than 300 enzymes and in processes as different as immunity, skin and fertility.

What is zinc?

It is a trace element: we need it in small amounts, but constantly, because the body does not keep a reserve it can use when intake falls short. That is why daily intake matters.

What does zinc do?

According to the health claims authorised in the European Union, zinc contributes to:

• the normal function of the immune system
• the maintenance of normal skin, hair and nails
• normal fertility and reproduction
• the maintenance of normal testosterone levels in the blood
• normal cognitive function
• the maintenance of normal bones and vision
• normal carbohydrate, fatty acid and macronutrient metabolism
• the protection of cells from oxidative stress

Which foods contain zinc?

• Shellfish: oysters are the most concentrated source.
• Meat, both red meat and poultry.
• Seeds, nuts, legumes and whole grains: they provide zinc, but their phytates reduce its absorption.
• Dairy and eggs, in smaller amounts.

Because of this lower absorption, vegetarians and vegans may need up to 50% more zinc than people who eat meat and fish.

How much zinc do you need per day?

EFSA sets requirements according to the phytate content of the diet: between 7.5 and 12.7 mg per day for women and between 9.4 and 16.3 mg per day for men. The nutrient reference value (NRV) shown on labels is 10 mg.

At IVB, Zinc Plus provides 25 mg of zinc in two forms (OptiZinc® and picolinate) together with 1 mg of copper. You will also find zinc in Myo-Inositol Plus, FertiUp and the VitalNatal range.

When can intake fall short?

• Vegetarian or vegan diets.
• Pregnancy and breastfeeding, when requirements increase.
• Older adults with a low intake.
• Digestive conditions that reduce absorption, or high alcohol intake.

The signs of insufficient intake are non-specific: more frequent infections, slow wound healing, hair loss or changes in taste. If you suspect a deficiency, talk to your healthcare professional.

Types of zinc

• Picolinate and bisglycinate: zinc bound to organic molecules, well absorbed.
• Zinc methionine (OptiZinc®): zinc bound to the amino acid methionine.
• Gluconate and citrate: common, well-tolerated forms.
• Oxide: provides a lot of zinc per gram, but is less well absorbed.

Safety and precautions

• Do not exceed the recommended daily dose. Taking high amounts of zinc for long periods can reduce copper absorption, which is why some formulas, such as Zinc Plus, include copper.
• If it upsets your stomach on an empty stomach, take it with food: nausea is the most common side effect.
• Take it apart from calcium or iron supplements and from some antibiotics (quinolones and tetracyclines). If in doubt, ask your pharmacist.

Frequently asked questions

What does zinc do for women?

Zinc contributes to the maintenance of normal skin, hair and nails, to normal fertility and reproduction and to the normal function of the immune system. Requirements are higher during pregnancy and breastfeeding.

What does zinc do for men?

Besides its roles in immunity, skin and hair, zinc contributes to the maintenance of normal testosterone levels in the blood and to normal fertility and reproduction.

Which foods are highest in zinc?

Oysters and other shellfish, red meat, pumpkin seeds, nuts, legumes and whole grains. Zinc from plant foods is less well absorbed.

When is the best time to take zinc?

With a main meal, to improve digestive tolerance, and apart from calcium or iron supplements.

References

1. EFSA NDA Panel. Scientific Opinion on Dietary Reference Values for zinc. EFSA Journal. 2014;12(10):3844.
2. National Institutes of Health, Office of Dietary Supplements. Zinc: Fact Sheet for Health Professionals.
3. Commission Regulation (EU) No 432/2012 establishing a list of permitted health claims made on foods, as amended.