adults

Zinc and copper: why one of them goes missing

Zinc and copper compete for the same route into the body. What that means over months, why the ratio everyone quotes has no official source, and what to check.

By Kiril Zlatkov · Aug 6, 2026 · 5 min read

10 to 1, which is what the EU reference values already are before anyone picks a ratio

You bought the zinc for a reason. It was on a shelf on its own, and nothing on the box mentioned anything else.

One of us took zinc that way for a long time, with no copper anywhere near it. She only worked out that it wasn't the right choice while researching what to put in our own formula, which is a slightly embarrassing way to find out and the reason this page exists.

The short answer

Zinc and copper use the same route into the body, and zinc is better at getting through it.
That matters over months, not days. A single high dose does nothing here.
The zinc-to-copper ratio you'll see quoted online has no regulator behind it. We looked.
Both are on our label at the same percentage of their reference value. That's the whole design decision.

They compete, and zinc usually wins

Zinc and copper are absorbed across the wall of the small intestine, and they use overlapping machinery to get there.

When zinc intake goes up, the cells lining the gut make more of a protein called metallothionein. Metallothionein binds both metals, but it holds copper more tightly. Copper that gets bound stays in the cell, the cell is shed and replaced in a few days, and the copper leaves with it.

So the effect isn't that zinc destroys copper. It's that zinc quietly makes copper harder to keep.

This is slow. It's a monthly and yearly effect, not something that happens to you on a Tuesday. Which is exactly why it's easy to miss: nobody feels a supplement doing this, and nobody is looking.

The ratio everyone quotes, and where it comes from

Search for this and you'll find a zinc-to-copper ratio of ten to one, stated confidently, usually without a source.

We went looking for the source. There isn't an official one. EFSA publishes dietary reference values for zinc and for copper as separate documents, each with its own reasoning. Neither sets a ratio between them. No EU authority does.

That doesn't mean the number is wrong. It means it's a rule of thumb that has been repeated until it sounds like a regulation, and you should know which of those you're reading.

Here's the part that is official, and it's more useful. The EU nutrient reference values, the figures used on every label in the bloc, are 10 mg for zinc and 1 mg for copper.

So if a product carries both at the same percentage of their reference values, the ratio comes out at ten to one on its own. Not because anyone chose ten to one. Because that's what the reference values already are.

What we did, and the part that isn't flattering

Both minerals are in all three of our formulas, at the same percentage of the reference value: 50% each in Kids, 100% each in Teens and Adults.

That's it. That's the entire decision. We didn't derive a ratio, we matched two numbers that already existed and let the ratio fall out.

The unflattering part: this is not clever, and we'd rather you knew that than thought it was. Any brand that includes copper at all arrives at roughly the same place. The interesting question isn't how we got to ten to one. It's why so many zinc products contain no copper whatsoever, and the answer is usually that a single-mineral product is simpler to make, simpler to market, and cheaper.

The other unflattering part: if you're taking a separate high-dose zinc supplement on top of anything, ours included, the sums stop being ours to do. Add them up.

What to check tonight

You can do this with whatever is in the cupboard.

Find the zinc product and read the panel. Is copper on it at all? On a lot of standalone zinc products it isn't.
If it's there, compare the two %NRV figures. If zinc is at 300% and copper at 40%, you're looking at a product that is going in one direction.
If it isn't there, look at how long you've been taking it. A month is not the question. A year is.
Add up everything. A multivitamin, a separate zinc, and a fortified cereal are three sources, and only you can see all three.
If you've taken high-dose zinc alone for a long stretch, that's a conversation with your GP, not a reason to buy something else. Copper status is measurable and we're not the ones to interpret it.

Where we actually fit

If you want zinc specifically, at a dose aimed at zinc, a standalone product will do that better than we will. Ours is a daily multinutrient, and every amount in it is sized for covering a normal gap rather than for correcting anything.

What we won't do is sell you zinc on its own and say nothing about copper.

Sources

Written by Lina and Stanislava, founders of MyDailyPocket. This is for information, not medical advice. Read the label, and talk to someone qualified if you're worried.