Zinc
Picolinate, gluconate, bisglycinate, ZMA: the forms of zinc, how much supplements contain, the upper limit and how to choose.
- Zinc contributes to normal DNA synthesis.
- Zinc contributes to normal acid-base metabolism.
- Zinc contributes to normal carbohydrate metabolism.
- Zinc contributes to normal cognitive function.
- Zinc contributes to normal fertility and reproduction.
- Zinc contributes to normal macronutrient metabolism.
- Zinc contributes to normal metabolism of fatty acids.
- Zinc contributes to normal metabolism of vitamin A.
- Zinc contributes to normal protein synthesis.
- Zinc contributes to the maintenance of normal bones.
- Zinc contributes to the maintenance of normal hair.
- Zinc contributes to the maintenance of normal nails.
- Zinc contributes to the maintenance of normal skin.
- Zinc contributes to the maintenance of normal testosterone levels in the blood.
- Zinc contributes to the maintenance of normal vision.
- Zinc contributes to the normal function of the immune system.
- Zinc contributes to the protection of cells from oxidative stress.
- Zinc has a role in the process of cell division.
The claims apply to a product whose daily dose provides at least 15 % of the reference intake (10 mg).
A varied and balanced diet and a healthy lifestyle are important.
What it is
Zinc is a trace mineral the body needs in small amounts but regularly: it hardly stores any. Meat, seafood (oysters above all), cheese, pulses, nuts and seeds are the richest sources. The EU labelling reference intake is 10 mg a day.
Zinc has one of the longest lists of authorised claims in the European Union — they are listed above. They apply to products whose daily dose provides at least 1.5 mg of zinc (15 % of the reference intake).
Forms of zinc
Like magnesium, zinc in supplements is bound to something else, and the pack states the amount of zinc itself. Gluconate and citrate are common, inexpensive forms. Picolinate and bisglycinate cost more; they are often chosen when zinc is taken on an empty stomach. Zinc oxide carries a lot of zinc per gram and turns up in multivitamins.
ZMA is a combination of zinc, magnesium and vitamin B6, usually as evening capsules.
How it is taken
A usual supplement dose is 10–25 mg of zinc a day. Zinc is better taken after a meal: on an empty stomach it makes some people nauseous. EFSA's tolerable upper level for adults is 25 mg a day from all sources, multivitamins included.
Large doses of zinc over a long time reduce the absorption of copper, which is why some products pair zinc with a little copper.
How to choose
Count the zinc you already get from a multivitamin and pick a dose that keeps the total under 25 mg. For daily use an inexpensive citrate or gluconate is enough; with a sensitive stomach, bisglycinate. If you also want magnesium, look at ZMA or complexes.
Frequently asked questions
How much zinc a day is safe?
The upper level for adults is 25 mg a day from all sources. The labelling reference intake is 10 mg.
Why does zinc make me feel sick?
It happens when it is taken on an empty stomach. Take zinc after a meal or choose the bisglycinate form.
What is ZMA?
A combination of zinc, magnesium and vitamin B6 in one capsule. It is usually taken in the evening, at the dose on the pack.
Can zinc be taken with magnesium?
Yes, ZMA and many complexes are made that way; follow each one's dose.
Zinc in the morning or evening?
There is no fixed time; what matters is taking it after a meal.
Why does zinc taste metallic?
Some forms do, especially lozenges. Capsules do not.
Zinc & ZMA in the shop
