Apart from proteins, fats and carbohydrates, cats need other nutrients such as vitamins. These are vital, as they also control metabolism processes and cannot be synthesized within the cat's body. The vitamins important for cats can be divided into fat-soluble and water-soluble vitamins.
- Vitamin A keeps skin and mucous membranes healthy, protects the body from infections and is important for growth, fertility and visual function. In contrast to humans, cats aren't able to synthesize vitamin A from vegetable carotene. They are completely dependent on a sufficient supply of vitamin A. This vitamin only occurs in animal food.
- Vitamin D is indispensable for ossification and keeping the skeleton healthy. If it lacks in the diet of an adolescent cat, this can lead to bone deformation, or to weakness of the bones in adult cats.
- Vitamin E fulfils many protecting functions in the body, and is responsible for fertility and a normal pregnancy.
- Vitamin K is essential for normal blood coagulation in the event of injuries, and is synthesized by microorganisms in the cat's intestines in a sufficient amount.
- The B vitamins are indispensable for the whole metabolism. This comprises the nervous system, the muscle function, skin and coat, blood formation and growth. A lack of B vitamins can lead to failures in liver function, and eczemas. A vitamin B deficiency occurs in cats that mainly live from a diet of uncooked freshwater fish or herrings. These fish contain a substance that destroys the vitamin B1 (thiamin) if they are eaten raw. Riboflavin (B2) controls the dissimilating metabolism and is responsible for normal growth. Niacin also has diverse tasks in metabolism. Pyridoxine (B6) contributes to protein metabolism and blood formation.
- Biotin, too, has its important role to play in metabolism. A lack of biotin leads to skin mutations or loss of hair, which are symptoms of disease in a cat. A healthy cat synthesizes biotin as well as ascorbic acid (vitamin C) in sufficient quantities. Biotin can become ineffective if fed with raw egg white, as egg white contains a substance that binds biotin and thus prevents it from being absorbed.
Vitamins and home-cooked cat food: Some of the fat-soluble vitamins such as vitamins A and E, as well as some of the water-soluble vitamins such as B1 and biotin, are partly destroyed upon cooking or have not been there in sufficient quantities in the first place. Because the exact amount of vitamins in the ingredients is not known, it is nearly impossible for the cat owner to prepare cat food that meets the vitamin requirements of the cat. To supplement homemade cat food with preparations containing vitamins is rather questionable because of the risk of under or over-dosage. If you choose to home cook your cat's meals, it's still a good idea to continue regular feedings of a commercially prepared cat food that's 100% nutritionally balanced and complete.