Vitamin A, D & E

Vitamins A, D and E are fat-soluble vitamins. Unlike water-soluble vitamins, which are readily excreted when consumed in excess, fat-soluble vitamins can be stored in the body, particularly in the liver and fatty tissues. This allows animals to draw on stored reserves between meals, but also makes careful formulation important: particularly in the case of vitamins A and D, both deficiency and prolonged excessive intake can have serious consequences.

Vitamin A

Vitamin A is essential for vision, immune function, reproduction, and the normal growth and maintenance of cells and tissues. Cats have a particularly interesting relationship with this vitamin. Unlike humans and many other animals, they cannot efficiently convert beta-carotene from plants into the active vitamin A they require. They have evolved instead to obtain preformed vitamin A, or retinol, directly from animal tissues.

In whole prey, vitamin A is concentrated particularly in the liver. Fresh liver is therefore an important part of the recipe for TCfeline Original. However, the amount of vitamin A supplied by liver is not necessarily consistent, particularly when dried liver products are used in place of fresh liver in the recipe. Many commercial liver powders are defatted, removing some of the fat-soluble vitamins, while vitamin A is also vulnerable to degradation during processing and storage. Analyses conducted by Feline Future found very low levels of naturally occurring vitamins A and D in liver powders we tested. For this reason, dried liver cannot simply be assumed to provide the same vitamin content as the equivalent amount of fresh liver.

TCfeline Original therefore includes a carefully calculated amount of vitamin A palmitate in addition to the vitamin A supplied by fresh liver. This provides a consistent nutritional foundation, whether the recommended fresh liver is used or freeze-dried liver is chosen as a substitute, while keeping total vitamin A within established safe intake levels when fresh liver is included.

TCfeline Special Formula does not require the addition of liver in any form. This simplifies preparation while making the formula particularly suitable for owners and cats that prefer a liver-free recipe. TCfeline Special Formula supplies all required vitamin A through the premix itself in supplemental form.

Vitamin D

Vitamin D plays an important role in regulating calcium and phosphorus metabolism and is therefore essential to normal skeletal development and maintenance, as well as having functions throughout the body.

Cats have very limited ability to synthesise vitamin D in their skin through exposure to sunlight and have evolved to obtain it from their food instead. Liver and other animal tissues contribute vitamin D in a natural prey diet, but, as with vitamin A, the amount supplied by processed liver products cannot be assumed to equal that of fresh liver.

TCfeline Original therefore includes vitamin D3 (cholecalciferol) at a carefully controlled level, supplementing the vitamin D naturally supplied by fresh liver. This ensures adequate and consistent vitamin D intake when either fresh or freeze-dried liver is used, while accounting for the additional vitamin D provided when fresh liver is included and keeping the total within established safe intake levels.

In TCfeline Special Formula, vitamin D3 takes the place of the dietary contribution normally made by liver. No fresh or freeze-dried liver is required, simplifying preparation and providing all required vitamin D directly through the premix.

Vitamin E

Vitamin E is an essential antioxidant. One of its important roles is protecting cell membranes and polyunsaturated fatty acids from oxidative damage. This is particularly relevant to a carnivorous diet containing animal fats and essential fatty acids.

TCfeline uses vitamin E succinate (alpha-tocopherol) rather than relying upon the relatively small and variable quantities naturally present in meat and liver. Vitamin E also helps protect fats in the prepared cat food from oxidation during preparation, freezing, storage and thawing, as well as helping to protect the ingredients in the dry premix itself.

Why the amounts matter

The fact that vitamins are essential does not mean that more is better. Vitamins A and D can accumulate in the body, and excessive supplementation can be harmful. TCfeline therefore provides these vitamins in calculated amounts designed to complement the other ingredients in each formula.
Additional vitamin A, D or E supplements should not be added to food prepared with TCfeline, nor should additional liver be used beyond the amount specified in the official recipe. The objective is not to maximise vitamin intake, but to provide an appropriate and dependable amount.