Pet Care - Frequently Asked Questions - Why does Burns Real Food contain synthetic but not natural vitamins?

Why does Burns Real Food contain synthetic but not natural vitamins?

Natural forms of vitamins and minerals are very unstable and consistency can never be guaranteed, this can cause large variations in nutritional levels. These large fluctuations can be detrimental to the quality of the food. The natural forms also have an unknown bio-availability and therefore specific levels cannot be guaranteed; they are also associated with undesirable substances for example heavy metals, which would be detrimental to the pet. The variability is too inconsistent for us to confidently use natural forms of vitamins and minerals.

The NRC (National Research Council) and AAFCO (Association of American Feed Control Officials) publish recommendations for the minimum levels of 17 vitamins and trace minerals that should be present in nutritionally complete pet foods. These figures are based upon deficiency and toxicity cases presented to vets, and some feeding trials. Natural ingredients, by definition, are very unlikely to contain consistent quantities of these nutrients (e.g. due to seasons, weather, soil type, etc) therefore, supplementation with exact quantities is necessary in order to prevent chronic deficiencies or toxicities.

Whilst it could be possible to reach the minimum levels necessary (using natural vitamins), the balance between nutrients is very important. For example, seaweed can contain high levels of magnesium which interferes with the uptake of zinc and copper from the diet. Also, in order to meet the minimum levels of less prevalent nutrients such selenium; you would need to add high quantities of seaweed, which could in turn lead to toxic levels of other nutrients, such as iodine. Many vitamins found in nature do not survive the cooking process. For example, the natural form of vitamin E is delta-tocopherol but this is virtually destroyed with mild processing temperatures. We add alpha-tocopherol, which survives very well and is absorbed efficiently from the gut.