Note: Unfortunately, not all feline nutritional
deficiencies have been documented so some symptoms listed here refer to
human deficiency. The ones referring to humans have an asterisk beside
the name.
Amino Acid Deficiencies: since cats are carnivores and meats contain all the essential amino acids, amino acid deficiencies are very unusual. The only reported deficiency is taurine since commercial foods did not contain taurine in sufficient levels until it was shown to be essential to cats. People and dogs can make their own taurine.
Taurine: blindness, possibly dilated cardiomyopathy, still births. Cats at greatest risk for taurine deficiency are those fed commercial foods for dogs or unbalanced home-made diets. Cats fed home-made diets should supplement on taurine.
Other essential amino acids:
Since meats contain all essential amino acids, a deficiency of any of the
essential amino acids would only occur in cats fed a vegetarian diet or
cats who are fed too much vegetables and too little meat.
Vitamins
Vitamin A: conjunctivitis, slow pupilary response to light, blindness, skin disorders, reproductive disorders, deafness; An excess or overdose of vitamin A causes serious bone lesions. Unlike many other animals, cats are incapable of using beta carotene as a source for vitamin A since they lack the enzyme carotenase. Therefore carrots and other vegetable sources for beta carotene are totally useless. Cats must acquire vitamin A from animal sources such as liver or fish oils. Vitamin A should never be supplemented without a prescription.
Vitamin B1: lack of appetite, coat problems, crooked position, convulsions and eventually death. Freshwater fish has considerable amounts of an enzyme called thiaminase that destroys vitamin B1. Therefore, cats who are fed raw or undercooked freshwater fish may be at risk for vitamin B1 deficiency. Since this vitamin is water-soluble, all excess is excreted by the kidneys.
Vitamin B2*: mouth lesions, skin lesions, lesions of the genital organs. This vitamin is water-soluble, all excess being excreted by the kidneys.
Vitamin B6*: anemia, seborrheic dermatitis, inflammation of the tongue. Megadoses of this vitamin should be avoided by cats who have a history of struvite crystals since this vitamin raises urinary pH. This vitamin is water-soluble, all excess being excreted by the kidneys.
Vitamin B12*: pernicious anemia, brain lesion. In humans, the absorption of this vitamin depends on an intrinsic factor, to make it simple, a hook on the intestines that attach to the vitamin and throw it into the blood. A deficiency may be caused by dietary lack of this vitamin or by lack of the intrinsic factor in the individual. I did not find in veterinary literature if the same holds true for cats. This vitamin is water-soluble, all excess being excreted by the kidneys.
Vitamin C: cats make their own vitamin C therefore it does not have to be present in their diet. Vitamin C may be used as a urinary acidifier (to lower urinary pH) but if used, should be diluted in water since the acid may hurt the cat's esophagus. This vitamin is water-soluble, all excess being excreted by the kidneys.
Vitamin D: cats who are allowed to sunbathe (not through glass) can make their own vitamin D but since many cats today are kept indoors only, supplementation is necessary. A deficiency of vitamin D results in rickets in young animals and abnormal softening of bones in adult animals. An overdose of vitamin D causes irreversible damage to certain body tissues such as heart valves and kidney tubules therefore this vitamin should never be supplemented without prescription.
Vitamin E: vitamin E is in fact a mixture of tocopherols. Deficiency of vitamin E causes a disease called steatites. The most obvious symptom of this disease is lethargy. In an early stage, the cat will refuse to move around but will otherwise seem absolutely normal. Cats at risk for steatites are those fed a home-made diet rich in meats but poor in fats. Although this vitamin is not water-soluble, it has no side effects if overdosed. Vitamin E helps protect the body tissues from oxidation (as do vitamins A and C) and eventually retard aging. Vitamin E protects from heart disease by inhibiting cholesterol oxidation and adhesion to blood vessel walls.
Vitamin K*: vitamin K is involved with coagulation of blood but needs not be supplemented since it is produced by the intestinal flora. A deficiency of vitamin K causes the inability of the blood to coagulate, colitis, internal and external bleedings. It is possible that cats who are given antibiotics for extended periods of time develop a deficiency of this vitamin. Vitamin K should never be supplemented without prescription.
Vitamin F (Linoleic Acid, Linolenic Acid, Arachidonic Acid)*: Deficiency of these oils cause eczema, acne and other disorders since they are used by the body for the production of many hormones and prostaglandins. Prostaglandins play an important role both in avoiding cancer as in fighting it off. Feline acne can certainly be caused by a deficiency of these oils. These oils may be supplemented - there are no overdose dangers. Animal fat contains 20 to 40% of linoleic acid providing the animal's dietary source is abundant.
Vitamin B3 (Niacin)*: reddening of the skin, digestive, nervous and mental disorders. This vitamin is water-soluble, all excess being excreted by the kidneys.
Vitamin B5 (Panthothenic Acid)*: hypoglycemia, duodenal ulcers, blood disorders, skin disorders. This vitamin is water-soluble, all excess being excreted by the kidneys.
Vitamin Bc (Folic Acid)*: nutritional macrocytic anemia, abortions, birth defects. Folic acid in diet must undergo changes once absorbed in order to become biologically active. Some people's livers are incapable of activating folic acid, therefore they need a supplementation of the active form. This may be true for cats. If your queen experiences idiopathic malformation of fetuses or idiopathic abortions, discuss folic acid supplementation with your vet. This vitamin is water-soluble, all excess being excreted by the kidneys.
Vitamin H (Biotin)*: face and body eczema, exhaustion, disorders in fat metabolism. Egg white contains a protein which inhibits the absorption of biotin therefore, if you do give raw egg whites to your cat, do so only sporadically. This vitamin is water-soluble, all excess being excreted by the kidneys.
Cholin*: possible deficiency symptoms are incoordination, kidney damage, hardening of arteries and veins, liver cirrhosis and adipose degeneration of the liver. Although this vitamin is not water-soluble, there are no reported overdose hazards.
Minerals
Calcium: muscle cramps, rickets, osteomalacia, osteoporosis; Cats fed home-made diets (usually rich in meats) should receive calcium supplementation. Do not attempt to supplement any mineral to your cat without a prescription though. Overdose of minerals can be quite toxic and may result in serious irreversible health problems or quick death.
Phosphorus: rickets, purulent inflammation of the teeth sockets. Phosphorus deficiency in felines is very unlikely since all meats have considerable amounts of phosphorus.
Iron: anemia. Excess iron results in soft stools of a very dark, sometimes greenish-black color. Cats fed too much liver may develop an iron overdose.
Other minerals: The other minerals, many of them not even listed in the AAFCO chart, are either needed in such minute amounts or they are so easily found in a variety of food sources that a deficiency would be unlikely.
Please, do not ever attempt to turn your cat into a vegetarian. Vegetables lack a great number of nutrients that are absolutely essential to cats. Animals fed balanced commercial diets should not supplement on vitamins A, D, K, C (to acidify urinary pH) and/or minerals unless prescribed by a veterinarian.
Note: Some foods contain excessive amounts of anions such as nitrates, nitrites and sulfates. These anions may contribute to deplete the body reserves of linoleic, linolenic and/or arachidonic acids. The most common symptom of this is feline acne. Please check the section on feline acne for more details.
Supplementation of the B vitamins is necessary for cats with CRF.