Vitamin D3 Supplement in dog and cat food

Is it OK for dogs and cats?

Dogs

Yes, at the levels used in complete dog foods. Dogs need vitamin D from their diet, and the risk comes from excess. The EU caps it at 2,000 IU per kg of complete food (at 12% moisture). In 2018 the FDA warned owners about recalled dry dog foods that tested at up to about 70 times the intended amount.

Cats

Yes, at normal levels. Cats also need vitamin D from food, and the same EU cap applies. FEDIAF's nutritional maximum for cats is much higher than for dogs. Excess can still harm cats: a 2021 report described five young cats that became ill after eating a kitten food with extremely high vitamin D3.

How settled this is: Limited by regulators

What vitamin d3 supplement is

Vitamin D3 supplement is cholecalciferol, one of the fat-soluble vitamins (A, D, E and K). In the EU it is authorised as a nutritional feed additive for all animal species under identification number 3a671. The authorised form is made by chemical synthesis and must be at least 80% cholecalciferol plus precholecalciferol. The current EU authorisation runs until 11 September 2027. US feed rules (21 CFR 582.5953) list vitamin D3 as generally recognised as safe when used in line with good manufacturing or feeding practice. Amounts are given in international units (IU): 1 µg of vitamin D3 equals 40 IU.

Why it is in pet food

Vitamin D is an essential nutrient in the diet of both dogs and cats. Unlike humans and many other mammals, dogs and cats have very little 7-dehydrocholesterol, the skin compound that sunlight turns into vitamin D3. So they rely on food for it. Its main job is to help the gut absorb calcium and phosphorus, move them where they are needed and build them into bone. A lack of vitamin D can cause rickets in young animals and weak bones in adults. The Merck Veterinary Manual says classic rickets is rare in puppies and kittens fed complete and balanced commercial foods. It is seen most often with homemade diets that have no supplement. In the EU, vitamin D3 must be added to feed through a premixture, a pre-blended mix of additives.

What it does in the food

Vitamin D3 provides vitamin D activity. Calcitriol (1,25-dihydroxycholecalciferol) is the active form of vitamin D in the body. FEDIAF's September 2025 guidelines give these minimums per 100 g of dry matter. Complete dog food: 50 to 63.9 IU, depending on life stage and energy intake. Complete cat food: 25 to 33.3 IU. FEDIAF notes that measuring vitamin D in foods close to these minimums is difficult and unreliable. It adds that testing is not required when the food is supplemented.

Safety and limits

Too much vitamin D is a known hazard for dogs and cats. The Merck Veterinary Manual says cases have been linked to vitamin D accidentally added in excess to commercial pet foods, and to pets eating rodent baits that contain cholecalciferol. Excess raises blood calcium and phosphorus. It can cause permanent calcium deposits in the kidneys, heart valves and large blood vessels, and can be fatal. In December 2018 the FDA reported recalls of several dry dog foods made by one contract manufacturer. The recalls followed complaints that dogs eating the food had vitamin D toxicity. Lab tests found up to about 70 times the intended amount of vitamin D. The FDA listed the signs of excess as vomiting, loss of appetite, increased thirst and urination, excessive drooling and weight loss. The FDA said only foods made for dogs were affected, and it closed the recall in July 2020. In cats, a 2021 case series described five young cats with high blood calcium of varying severity. They had eaten a fish-based complementary kitten food with extremely high vitamin D3. The cats were treated by stopping the food and with medical care. All recovered except two, which developed chronic kidney disease. Limits: the EU caps vitamin D3 at 2,000 IU per kg of complete food at 12% moisture for species without their own limit, which includes dogs and cats. FEDIAF converts this to 227 IU per 100 g dry matter. FEDIAF's science-based nutritional maximum for dogs is 320 IU per 100 g dry matter, set from studies in growing Great Dane puppies. For cats it is 3,000 IU per 100 g dry matter. The EU authorisation also says breathing in the concentrated additive is very hazardous. It requires feed businesses to protect the people who handle the additive and premixtures.

What depends on the amount and the recipe

What matters is the amount in the finished food, not whether vitamin D3 is on the label. The problem cases cited here involved foods with far more vitamin D than intended or declared. FEDIAF notes that the EU legal maximum applies once vitamin D is added as an additive. It then covers the total in the food, including vitamin D from other ingredients. If vitamin D comes only from ingredients, the legal maximum does not apply, and FEDIAF says its nutritional maximum should be taken into account. In the 2021 cat case series, the food was labelled additive-free, yet its vitamin D3 was 44 times FEDIAF's nutritional maximum for cats. The producer said contamination of raw materials was the most likely cause, and recalled the food. For dogs, size and life stage matter. FEDIAF bases its maximum on growing giant-breed puppies and uses it for all life stages, because there is no information on safe maximums for adult dogs and breeding bitches. FEDIAF's nutritional maximum for cats is far higher than for dogs, but the EU legal limit is the same for both.

Not the same as

• Vitamin D2 (ergocalciferol) — A different form of vitamin D, listed separately in US feed rules (21 CFR 582.5950). The EU does not allow it to be used together with added vitamin D3, and cats use D2 less efficiently than D3.
• Cholecalciferol rodent bait — The same chemical, but in a rat and mouse poison, not a food ingredient. Pets that eat these baits can develop vitamin D poisoning.
• Calcitriol (1,25-dihydroxycholecalciferol) — The active hormone the body makes from vitamin D. It is not the form listed as vitamin D3 supplement.
• 25-hydroxycholecalciferol — A different vitamin D compound. The EU sets a combined cap for it and vitamin D3 in poultry and pig feed.

Sources

1. FEDIAF Nutritional Guidelines for Complete and Complementary Pet Food for Cats and Dogs (September 2025) — FEDIAF – European Pet Food Industry Federation, 2025. Vitamin D minimums for dogs (50–63.9 IU/100 g DM) and cats (25–33.3 IU/100 g DM); EU legal limit of 227 IU/100 g DM; nutritional maximums of 320 IU for dogs (based on Great Dane puppy studies, applied to other life stages for lack of data) and 3,000 IU for cats per 100 g DM; the legal maximum covers the total content once the vitamin is added, and does not apply when vitamin D comes only from feed materials; vitamin D analysis note; 1 µg D3 = 40 IU.
2. Commission Implementing Regulation (EU) 2019/849 amending Implementing Regulation (EU) 2017/1492 – current Annex for cholecalciferol (vitamin D3, 3a671) as a feed additive for all animal species — EUR-Lex (Publications Office of the European Union), 2019. Cholecalciferol is authorised as a nutritional additive for all animal species (3a671); made by chemical synthesis, at least 80% cholecalciferol plus precholecalciferol; maximum 2,000 IU/kg complete feed (12% moisture) for other animal species; must be added via a premixture; not to be used together with vitamin D2; combined cap with 25-hydroxycholecalciferol for poultry and pigs; very hazardous by inhalation, so users need protective measures; authorisation runs to 11 September 2027.
3. 21 CFR 582.5953 Vitamin D3 (and 582.5950 Vitamin D2), Code of Federal Regulations, 2024 edition — U.S. Government Publishing Office (govinfo), 2024. Vitamin D3 (and separately vitamin D2) are generally recognised as safe in animal feed when used under good manufacturing or feeding practice.
4. FDA Alerts Pet Owners about Potentially Toxic Levels of Vitamin D in Several Dry Pet Foods — U.S. Food and Drug Administration, Center for Veterinary Medicine, 2018. Recalls of dry dog foods from a common contract manufacturer after complaints of vitamin D toxicity in dogs; lab results of up to about 70 times the intended vitamin D; signs of excess; FDA said only foods made for dogs were affected; recall terminated 17 July 2020.
5. Nutritional Requirements of Small Animals (Merck Veterinary Manual, full review Nov 2023, updated Sept 2024) — Merck & Co. / Merck Veterinary Manual, 2024. Vitamin D is essential in dog and cat diets; dogs and cats have little 7-dehydrocholesterol in the skin; vitamin D's role in calcium and phosphorus; calcitriol is the active form; rickets is rare on complete commercial diets; excess, linked to accidental over-addition in pet foods or to cholecalciferol rodenticides, causes high blood calcium and phosphorus and soft-tissue calcification; fat-soluble vitamins A, D, E and K.
6. Vecchiato CG et al. Case Report: A Case Series Linked to Vitamin D Excess in Pet Food: Cholecalciferol (Vitamin D3) Toxicity Observed in Five Cats. Frontiers in Veterinary Science 8:707741 — Frontiers in Veterinary Science (peer-reviewed), 2021. Five young cats with high blood calcium of varying severity after eating a fish-based complementary kitten food very high in vitamin D3; treated by withdrawing the food plus medical care; all recovered except two, which developed chronic kidney disease; the food was labelled additive-free and reached 44 times FEDIAF's cat nutritional maximum; the producer's view was that raw-material contamination was the most likely cause, and it recalled the food; cats use D2 less efficiently than D3.

Checked against these sources on 2026-10-15. Definitions are in our own words. This is a reading aid, not veterinary advice: a vet who knows your animal comes first.