Vitamin K is essential for the synthesis of blood clotting factors and also plays a role in bone metabolism. Cats obtain vitamin K from dietary sources (particularly liver and green vegetables) and from synthesis by beneficial bacteria in the gut. Under normal circumstances, healthy cats on balanced diets do not develop vitamin K deficiency. The most common clinical scenario involving vitamin K in cats is poisoning from anticoagulant rodenticides, which block vitamin K recycling and cause uncontrolled bleeding.
A small piece of cooked chicken or a leaf of spinach provides more than enough vitamin K for your cat's daily needs. Your adult cat needs roughly 0.05–0.2mg per day, which is comfortably supplied by any complete commercial diet. Supplementation is only necessary under veterinary direction, typically as an antidote to rodenticide poisoning.
0.0% of daily nutrient intake
Vitamin K makes up 0.0% of your cat's total daily nutritional requirements by weight. That's a tiny amount — but it matters.
Excessive or prolonged bleeding from minor wounds, bruising, blood in urine or stool, and internal hemorrhage. Dietary deficiency is extremely rare; clinical vitamin K deficiency in cats is almost always caused by rodenticide ingestion or severe liver disease.
Vitamin K from dietary sources (phylloquinone/K1) has a wide safety margin. The synthetic form menadione (K3), which was used in some older pet food formulations, can cause toxicity at high doses, but K1 and K2 from food are safe.
| Life Stage | Size | Min | Max | Unit | Notes |
|---|---|---|---|---|---|
| Adult | — | 0.05 | 0.2 | mg | Healthy cats with normal gut bacteria and balanced diets rarely need vitamin K supplementation. Clinical deficiency is almost always from rodenticide poisoning. |
Source: NRC 2006, general veterinary consensus
