Hypervitaminosis

The result of toxic levels of vitamins on the system

Vitamin A

Beta-carotene & retinol Beta-carotene sources: carrots, dandelion greens,

broccoli, kale spinach, turnips, apricots, melon, sweet potato

Retinol sources: fish liver oils, diary, egg yolks, liver Function:

– Maintains healthy coat & skin– Promotes bone growth– Protects against infection– Aids in treatment of eye disorders

Hypervitaminosis A

Highest occurence in cats fed mostly on liver Produces bone hypertrophy (bone growths)

and ankylosing spondylosis (bone fusion) of cervical vertebrae

Also effects foetal brain and eye development

Symptoms in cats

Kangaroo sitting Inability to move head or neck Pain Forelimb lameness

Diagnosis and Treatment

Diagnosis by radiography

Prognosis guarded to poor

Cessation of vitamin intake may halt progression, but will not reduce spondylosis

Signs in other animals

ChicksLoss of appetitePoor growthDiarrhoeaEncrustation around mouthReddening of eyelids

PigsRough coatScaly skinHyper-irritabilityHaemorrhages over limbs and abdomenPeriodic tremorsDeath

B Vitamins

B-1 – Thiamine Source: beef liver, kidneys, whole grains, bran

oatmeal, salmon, wheat germ, peanuts & kidney beans

Function – Formation of cocarboxylase enzyme involved in

decarboxylation (citric acid cycle)– Maintains normal function of nervous system– Improves brain power

Hypervitaminosis B-1

B-1 symptom – curare like i.e. paralysis– Blocks nerve transmission– Restlessness, convulsions and labored

respiration– Death results from respiratory paralysis and

cardiac failure

B Vitamins

B-2 – Riboflavin Source: cottage cheese, cheese, wheat germ,

kidney, fish & chicken Function

– Flavoproteins in oxidative phosphorylation– Maintains healthy mucous membranes– Promotes growth– Contributes to vision

Hypervitaminosis B-2

B-2 symptom - Bright yellow urine– Itching– Numbness– Burning or prickling sensations– Sensitivity to light

B Vitamins

B-3 – Niacin Source: beef liver, white chicken meat, peanuts,

salmon, tuna, turkey, whole grains & milk Function

– Coenzyme in hydrogen transport– Maintains muscle tone, healthy skin & coat– Converts food to energy– Prevents seizures (in some cases)

Hypervitaminosis B-3

B-3 symptom – low blood pressure and lightheadedness– Liver damage– Peptic ulcers– Skin rashes

B Vitamins

B-5 – Pantothenic Acid Source: eggs, wheat germ, lentils, liver,

brewers yeast, peas & whole grains Function

– Constituent of coenzyme A (CoA)– Improves longevity– Aids in wound healing– Protects against stress & infection

Hypervitaminosis B-5

B-5 – symptom

– diarrhea

B Vitamins

B-6 – Pyridoxine Source: bananas, bran, brewers yeast, carrots,

salmon, tuna, wheat germ, lentils, whole grain cereals

Function– Coenzyme for amino & fatty acid metabolism– Promotes red-blood cell formation– Maintains strong immune system– Contributes to healthy nervous system

Hypervitaminosis B-6

B-6 – symptom – neurological disorders– Nerve damage in limbs– Effects balance & co-ordination– Decrease sensation to touch and temperature

B Vitamins

B-12 – Cyanocobalamin - produced by intestinal bacteria

Source: sardines, herring, milk products, eggs, organ meats (liver, kidney, brain) & beef

Function– Nucleoprotein synthesis– Formation of erythrocytes (red blood cells)– Used to treat anaemia– Promotes normal growth– Stimulates weight gain in puppies

Hypervitaminosis B-12

B-12 – reduction in size of vascular controlled reflexes

B Vitamins

Biotin – A B vitamin also known as Vitamin H Source: brown rice, diary products, egg yolk,

chicken, liver, tomatoes, lentils & oats Function

– Protein & Fatty acid synthesis– Prevents skin problems– Facilitates metabolism of amino acids & carbohydrates– Promotes health of nerve cells

Hypervitaminosis Biotin

Biotin – Scurfy skin, due to hyperkeratosis of the

superficial follicular epithelia

Vitamin C

Ascorbic Acid Source: oranges, peppers, tomatoes, broccoli, kiwi,

rose hips, strawberries (most fruit & veg) Function

– Essential for formation of collagen– Promotes tissue & wound healing– Can detoxify blood– Can reduce pain of arthritis

Hypervitaminosis C

may acidify the urine, cause nausea and diarrhoea, interferes with the healthy antioxidant-

prooxidant balance in the body in patients with thalassemia or

haemochromatosis, promote iron overload

Vitamin D

Cholecalciferol Sources: sun exposure, salmon, sardines,

cod-liver oil, herring & mackerel Function:

– Used by Osteoclasts in bone for demineralization

Hypervitaminosis D

Causes high levels of calcium and phosphorus in blood, arteries and organs

Via re-absorption of bone and deposits of calcium in soft tissue

– i.e. calcification in ox heart dissected in class

Bone

We constantly renew bone Calcium and phosphate in blood plasma help

to make bone Vitamins A & D also aid parathyroid hormone

in bone demineralization High levels of Vitamin D may produce bone

re-absorption without parathyroid hormone

Vitamin E

Alpha-tocopherol (antioxidant) Source: wheat germ, whole wheat floor, margarine,

corn oil, peanut oil & eggs Function

– Anti-blood clotting agent– Promotes muscle growth & repair– Improves immune system– Promotes healing of skin problems– Improves heart & circulatory system

Hypervitaminosis E

Vitamin E inhibits vitamin K and therefore reduces platelet production

Increased bleeding Impaired immune system – causing necrotizing

enterocolitis Diarrhoea and intestinal cramps include fatigue, muscle weakness, delayed

wound healing, and headaches

Vitamin K

Phytonadione - produced by intestinal bacteria

Source: alfalfa, cheddar cheese, oats, spinach & brussel sprouts

Function– Prevents abnormal bleeding– Used by the liver to make blood platelets

Used to treat dogs poisoned by warfarin

Hypervitaminosis K

Causes excess clotting of the blood

– leading to thrombosis and potential sudden death should clots form in brain or heart

Folic Acid

Folacin, pteroylglutamic acid Sources: Meats Function

– Nucleoprotein synthesis– Formation of erythrocytes (red blood cells)

Hypervitaminosis Folic Acid

– Inhibition of hepatic alcohol dehydrogenase– Stomach problems– Sleep problems– Skin reactions

Storage

Vitamins C, B & A (beta-carotene) are water soluble and quickly eliminated from the body

Vitamins A (retinol), D & E are fat soluble and become concentrated in the liver

Vitamin K is also fat soluble

N.B. up to 20 times the RDA of vitamins & minerals have been found in commercial pet food