Fat-Soluble and Water-Soluble Vitamins for Cats and Dogs

Vitamins are essential for life and growth processes by acting as catalysts in many metabolic reactions and aiding in the metabolism of the energy nutrients.  If a vitamin needed to produce a specific enzyme is not present, the chemical reactions controlled by that enzyme cannot take place.  Likewise, the absence of vitamins in the diet results in specific deficiency diseases as well as impaired growth and development.  Vitamins work with minerals and enzymes to support an animal's digestion, reproduction, muscle and bone growth, and healthy skin and haircoat.

Vitamins are divided into two groups: water-soluble (B-complex and C) and fat-soluble (A, D, E and K). Unlike water-soluble vitamins that need regular replacement in the body, fat-soluble vitamins are stored in the liver and fatty tissues, and are eliminated much more slowly than water-soluble vitamins. Some health problems may decrease the absorption of fat, and in turn, decrease the absorption of vitamins A, D, E and K.

Fat-soluble Vitamins

Vitamin A plays an important role in bone growth, tooth development, reproduction, cell division and gene expression. Also, the skin, eyes and mucous membranes of the mouth, nose, throat and lungs depend on vitamin A to remain moist.
Sign of deficiency: Conjunctivitis; cataracts, retinal degeneration, and other eye problems; weight loss; muscle weakness; reproductive and developmental disorders
Signs of excess: Skeletal lesions in kittens, particularly outgrowths of the cervical vertebrae, osteoporosis
Vitamin D plays a critical role in the body’s use of calcium and phosphorous. It increases the amount of calcium absorbed from the small intestine and helps form and maintain bones. Puppies and kittens especially need adequate amounts of vitamin D to develop strong bones and healthy teeth.
Signs of deficiency: Rickets; abnormalities in skeletal development; progressive paralysis; reduction in body weight and food intake
Sign of excess: Poor appetite; vomiting; lethargy; calcification of soft tissues.
Vitamin E acts as an antioxidant, protecting vitamins A and C, red blood cells and essential fatty acids from destruction.  Research has shown that vitamin E may help prevent heart disease and cancer.
Signs of deficiency: Poor appetite; depression; pain sensitivity in abdomen; fat tissue pathology
Vitamin K plays an essential role in normal blood clotting and helps promote bone health.
Signs of deficiency: Excess bleeding; prolonged blood clotting time.

Water-soluble vitamins

B-complex vitamins and vitamin C are water-soluble vitamins that are not stored in the body, are eliminated in urine, and must be replaced each day. All cats and dogs need a continuous supply of them in their diets.

Vitamin C helps hold body cells together, aids in wound healing, assists in bone and tooth formation, strengthens the blood vessel walls, is vital for the fuunction of the immune system, and improves absorption and utilization of iron. It also helps prevent nutritional ailments such as scurvy. Vitamin C serves as an antioxidant, and works with vitamin E as a free-radical scavenger. Studies suggest that vitamin C may reduce the risk of certain cancers, heart disease and cataracts.

Eight of the water-soluble vitamins are known as the B-complex group: thiamin (vitamin B1), riboflavin (vitamin B2), niacin, vitamin B6, folate, vitamin B12, biotin and pantothenic acid. These vitamins are widely distributed in foods. They function as coenzymes that help the body obtain energy from food. They also are important for normal appetite, good vision, healthy skin, a healthy nervous system and red blood cell formation.

Vitamin B1 (thiamin) Signs of deficiency: Neurological impairments including altered reflexes and convulsive seizures; heart-rate disorders; pathological changes in the central nervous system

Vitamin B2 (riboflavin)
Signs of deficiency: Cataracts; fatty livers; testicular atrophy

Vitamin B3 (niacin)
Signs of deficiency: Poor appetite; weight loss; fiery red tongue, with ulceration and congestion

Vitamin B5 (pantothenic acid)
Signs of deficiency: Stunted growth; fatty changes in liver; small bowel lesions

Vitamin B6 (pyridoxine)
Signs of deficiency: Stunted growth; convulsive seizures; kidney lesions

Vitamin B12 (cyanocobalamin) and Folic Acid
Signs of deficiency: Weight loss; vomiting; diarrhea; intestinal disorders

Biotin is a co-enzyme necessary for many reactions in the body. It assists in the making of fatty acids, and in the burning up of fatty acids and carbohydrates for body heat and energy. It also aids in the utilization of amino acids, folic acid, pantothenic acid, and vitamin B12.
Signs of deficiency: dermatitis and muscle pains

Folic acid (folate)
Signs of deficiency: Decreased growth rate; increased iron levels in blood.


Minerals are found in the bones, teeth, soft tissue, muscle, blood, and nerve cells.  They act as catalysts for many biological reactions within the body, including digestion and metabolism of food, transmission of messages throughout the nervous system, and muscle response.  They are also important in the production of hormones.  There is a synergism that occurs between minerals and other nutrients in the body, and the actions of specific minerals are dependent on the presence and proper amounts of other nutrients. 

Calcium is essential to the formation of bones and teeth; blood coagulation; nerve impulse transmission; muscle contraction; cell signaling.
Signs of deficiency: Nutritional secondary hyperparathyroidism; loss of bone mineral content, which can lead to collapse and curvature of lumbar vertebrae and pelvic bones; bone pain, which can progress to fractures.

Chromium is a trace mineral that is essential for the transfer of sugar from the bloodstream to muscle cells, thereby giving them the fuel they need to work.  Chromium is involved in maintaining cholesterol and triglyceride levels, and is necessary for muscle function.

Iodine is important for thyroid hormone synthesis; cell differentiation; growth and development of puppies; regulation of metabolic rate.
Signs of deficiency: Enlargement of thyroid glands
Signs of excess: Excessive tearing, salivation and nasal discharge; dandruff

Iron is essential to hemoglobin and myoglobin synthesis; energy metabolism.
Signs of deficiency: Poor growth; pale mucous membranes; lethargy; weakness; diarrhea
Signs of Excess: Vomiting and diarrhea

Magnesium is needed for enzyme functions; muscle and nerve cell membrane stability; hormone secretion and function; mineral structure of bones and teeth.
Signs of deficiency: Poor growth; overextension of the carpal joints; muscle twitching; convulsions
Signs of excess: Urinary tract stone formation in the presence of high pH

Phosphorus is needed for skeletal structure; DNA and RNA structure; energy metabolism; locomotion; acid-base balance
Sign of deficiency: Hemolytic anemia; locomotor disturbances; metabolic acidosis

Potassium is needed for acid-base balance; nerve-impulse transmission; enzymatic reactions; transport functions
Signs of deficiency: Poor appetite; retarded growth; neurological disorders, including severe muscle weakness

Selenium is important for defense against oxidative damage; immune response

Zinc is needed for enzyme reactions; cell replication; protein and carbohydrate metabolism; skin function; wound healing
Skin lesions; growth retardation; testicular damage.

Amino acids

There are 22 different amino acids that mammals need for various metabolic and energy activities.  Dogs and cats are able to manufacture 12 of these, but need to get the rest in their diets.   Because they are only obtained through food, they are called essential amino acids. 

Additionally, cats require taurine in order to live. Without it, our feline friends develop dramatic health problems, including reproductive failure, growth retardation, retinal degeneration and heart failure.