Chelated Minerals (Amino Acid Chelates and Proteinates) in dog and cat food
Chelated minerals are trace minerals, such as zinc, iron, copper and manganese, bound to amino acids (amino acid chelates) or to hydrolysed protein (proteinates). Pet food makers add them to supply trace minerals that dogs and cats need, sometimes in place of inorganic salts such as sulfates. Some dog studies found them better absorbed, but results are mixed. EU rules cap the total amount of these minerals in pet food when they are added.
Is it OK for dogs and cats?
- Dogs
- Yes, they are a normal way to supply essential trace minerals in a complete food. When these minerals are added, EU rules cap the total zinc, copper, iron and manganese in dog food. The total matters because better-absorbed forms deliver more. A 2019 veterinary expert panel believes a shift to more absorbable copper in dog-food premixes is linked with copper build-up in dogs' livers. The forms it named were copper salts, not amino acid chelates.
- Cats
- Yes, they are a normal way to supply trace minerals that cats need. The same EU caps apply to cat food. For zinc the limit is 200 mg/kg of complete food at 12% moisture, the same as for dogs. Cat research is limited. One 90-day study, funded by a mineral maker, tested a related form (amino-acid-complexed minerals). Cats had less dander and a trend to less shedding at day 45, and no differences at day 90.
How settled this is: Limited by regulators
What chelated minerals (amino acid chelates and proteinates) is
A chelated mineral is a trace mineral held by an organic molecule rather than paired with an inorganic partner such as sulfate or oxide. In EU feed-additive law, 'zinc chelate of amino acids hydrate' is a complex in which zinc and amino acids from soya protein are chelated through coordinate covalent bonds. It is sold as a powder with at least 10% zinc. A related EU form, 'zinc chelate of protein hydrolysates', must have at least 85% of its zinc chelated. Proteinates bind the mineral to hydrolysed protein. A 2025 paper notes that AAFCO groups organic trace minerals into four classes: metal amino acid complexes, amino acid chelates, metal proteinates and polysaccharide metal complexes.
Why it is in pet food
Dogs and cats need zinc, copper, iron and manganese, and FEDIAF sets minimum recommended levels for each in complete foods. Under EU rules, trace minerals added to pet food are nutritional additives. AAFCO's consumer guide says chelated and complexed mineral forms are thought to work more effectively than inorganic mineral compounds. One proposed reason is that a mineral bound to an organic molecule is less likely to form insoluble complexes with phytate from plant ingredients before it is absorbed.
What it does in the food
These ingredients supply essential trace elements: zinc, copper, iron or manganese. How well the mineral is absorbed can differ by form. In dogs, one study ranked zinc amino acid chelate above zinc sulfate, and zinc sulfate above zinc oxide. Another found that most zinc markers did not change between zinc proteinate and zinc sulfate. A 2021 review called the results controversial and said the effect of source is clearest after a period of low zinc intake. FEDIAF notes that absorption of trace elements is reduced by high calcium, by other trace elements (high zinc lowers copper absorption) and by phytate. It also says copper oxide is poorly available.
Safety and limits
EU: a 2016 regulation re-authorised zinc sources for all animal species, including zinc chelate of amino acids hydrate. It notes EFSA's conclusion that these sources have no adverse effect on animal or human health under the proposed conditions of use. It set a maximum of 200 mg/kg total zinc in complete feed (12% moisture) for dogs and cats. That is down from 250 mg/kg, mainly to limit zinc release into the environment. FEDIAF's 2025 guidelines list EU legal limits for copper, iron, manganese and zinc. A legal limit applies when the element is added as an additive. It covers the total in the food, from the additive plus the other ingredients. Dogs: a 2019 ACVIM consensus panel said it believes two things are linked with more copper build-up in dogs' livers. One is dietary guidelines; at the time, AAFCO set a copper minimum but no maximum. The other is a change in dog-food premixes from copper oxide (about 5% bioavailable) to more available forms (about 60-100%). The panel called these forms chelates, but the examples it gave were copper acetate, sulfate and carbonate. Cats: the EU zinc cap is the same as for dogs. The sources cited here include little research on chelated forms in cats.
What depends on the amount and the recipe
Which mineral it is, how much ends up in the finished food, and its form all matter. Absorption depends on the type of chelate and how stable it is in the gut. It also depends on calcium, other trace minerals and phytate in the recipe. A better-absorbed form delivers more of the mineral at the same amount on paper. The 2019 ACVIM panel made this point about copper in dog foods.
Not the same as
- Metal amino acid complexes (e.g. zinc amino acid complex) — AAFCO lists amino acid complexes as a separate class from amino acid chelates, though both are organic mineral sources. Labels can blur the two: the EU definition of zinc chelate of amino acids hydrate itself calls it a zinc amino acid complex.
- Polysaccharide metal complexes — Another separate AAFCO class of organic mineral ingredient, in which the mineral is complexed with a polysaccharide.
- Inorganic mineral salts (zinc sulfate, zinc oxide, copper sulfate, iron sulfate) — They supply the same minerals bound to an inorganic partner. Absorption can differ by form; FEDIAF advises that copper oxide is poorly available.
- Sodium selenite — An inorganic selenium source with its own page; it is not a chelate.
Also printed as
zinc amino acid chelate · iron amino acid chelate · copper amino acid chelate · manganese amino acid chelate · zinc proteinate · copper proteinate · manganese proteinate · iron proteinate · chelated minerals · zinc chelate of amino acids hydrate · copper chelate of amino acids hydrate · copper(ii) chelate of amino acids hydrate · iron(ii) chelate of amino acids hydrate · manganese chelate of amino acids hydrate · zinc chelate of protein hydrolysates · zinc chelate of glycine hydrate
Related
Sources
- What's in the Ingredients List — AAFCO. Metal amino acid complexes, metal amino acid chelates and polysaccharide complexes are classes of mineral ingredients thought to work more effectively than inorganic mineral compounds; selenite is an inorganic mineral compound.
- Commission Implementing Regulation (EU) 2016/1095 on zinc compounds as feed additives — Official Journal of the European Union, 2016. Zinc compounds are nutritional additives (compounds of trace elements); definitions of zinc chelate of amino acids hydrate (soya amino acids chelated via coordinate covalent bonds, at least 10% zinc) and zinc chelate of protein hydrolysates (at least 85% chelated); EFSA conclusion of no adverse effect on animal and human health; maximum total zinc of 200 mg/kg complete feed (12% moisture) for dogs and cats, based mainly on environmental impact.
- FEDIAF Nutritional Guidelines for Complete and Complementary Pet Food for Cats and Dogs (2025) — FEDIAF (European Pet Food Industry Federation), 2025. Minimum recommended levels and EU legal limits for copper, iron, manganese and zinc in dog and cat food; legal limits apply when the element is added as an additive and relate to the total amount; calcium, other trace elements (high zinc lowers copper absorption) and phytate reduce trace-element availability; copper oxide should not be counted as a copper source.
- Pereira AM et al. Zinc in Dog Nutrition, Health and Disease: A Review. Animals 11:978 — Animals (MDPI), via PubMed Central, 2021. Organic zinc sources considered more bioavailable despite controversial results, with the effect clearest after zinc restriction; Lowe studies ranking amino acid chelate > sulfate > oxide; zinc proteinate vs sulfate study with most markers unchanged; chelate stability varies; EU zinc cap lowered from 250 to 200 mg/kg because of environmental release; a zinc chelate is in theory less prone to form insoluble complexes with phytate.
- Webster CRL et al. ACVIM consensus statement on the diagnosis and treatment of chronic hepatitis in dogs. J Vet Intern Med 33:1173 — Journal of Veterinary Internal Medicine, via PubMed Central, 2019. Panel believes NRC and AAFCO guidelines (AAFCO: copper minimum, no maximum) and a change to more bioavailable copper premixes are linked with increased hepatic copper accumulation in dogs; copper oxide about 5% vs about 60-100% for the forms the panel calls chelates (acetate, sulfate, carbonate).
- Amundson LA et al. Effect of Supplemental Trace Mineral Source on Haircoat and Hair Loss in Adult Cats. Animals 15:2662 — Animals (MDPI), via PubMed Central, 2025. Cat study funded by Zinpro comparing sulfate and lysine/glutamic-acid-complexed zinc, manganese, copper and iron: better dander scores and a trend to less shedding at day 45, no differences at day 90; little is known about trace minerals in cats; lists AAFCO classes of organic trace minerals, including proteinates (hydrolysed proteins).
Checked against these sources on . Definitions are in our own words. This is a reading aid, not veterinary advice: a vet who knows your animal comes first.