Vitamins Organic compounds necessary for normal physiologic function. Most cannot be synthesized in the body and must be present in the diet.

There are two categories of Vitamins 1.Fat soluble (A, D, E, and K) 2.Water soluble (B complex vitamins and vitamin C)

1. Fat Soluble Vitamins (A, D, E, & K) Require bile salts and fat clusters for absorption through the wall of the duodenum and ileum. Are stored in lipid deposits in all tissues and are therefore required in smaller daily doses. Over supplementation may lead to toxic syndromes. More is not better and will not improve performance.

Vitamin A, D, E & K Sources A: Cod liver oil, milk, liver, egg yolk D: Liver, some fish, egg yolk, sunlight E: Wheat germ, corn and soybean oils K: Green leafy plants, liver, some fish meals This information is not in your book.

Vitamin A Plant sources have carotenoids (provitamin A) Dogs can convert this to the active form needed. Cats do not have the enzymes necessary to convert this to the active form. (another reason cats should not be fed vegetarian diets)

Vitamin D Dogs and cats cannot use sunlight to convert provitamin D to the active form. The active form of vitamin D is a hormone that works with calcitonin (parathyroid hormone), calcium, and phosphorus.

Vitamin E Main function is an antioxidant. This makes it useful as a preservative in pet food. Pansteatitis

Antioxidants Antioxidants function by stabilizing free radical molecules, which otherwise would have destructive interactions with surrounding tissues. They help to restore damaged tissues.

Vitamins C and E are Antioxidants These vitamins help free the body of the damaging effects of free radicals. Supplementation of these vitamins above the normal daily requirements can therefore be beneficial to the animal. In this case more means better. But don’t go vitamin crazy.

Vitamin K Can be absorbed from dietary sources or synthesized by microbes in the large intestines of dogs and cats

Vitamin K Deficiency Vitamin K plays a critical role in blood clotting formation! This means that deficiencies = hemorrhage (bleeding to death) Warfarin is a rodent poison that when ingested by cats from eating a rat or mouse, causes fatal hemorrhage if emergency supplementation of vitamin K is not administered.

2. Water Soluble Vitamins (B complex vitamins and vitamin C) Are poorly stored in the body Excesses are lost via the urinary tract Frequent intake is critical Depleted faster, so that toxic effects are less likely to occur than deficiencies

Vitamin C Ascorbic Acid An important water soluble vitamin, but is not necessary in the diet of dogs and cats as metabolism of glucose produces adequate amounts Serves as an antioxidant