Chapter 20: Nutritional Application of Vitamins to Human and Animal

Health

• Chapter overview:– Chapter 20 presents the impacts of vitamins on

animal health:• identification and sources of the vitamins

• functions of the vitamins

• impacts of vitamin deficiencies

Historical Perspective:

• Funk (1912) - introduced the term vitamine, meaning “vital amine”

• Later the word vitamin was adopted, also referring to the latin term vita for “life”

Vitamin Definition:

• Organic compounds essential for normal growth and maintenance of life– Required only in minute amounts– Do not contribute energy, but some are critical to

metabolism of energy– Some are metabolic, but not dietary, essentials

due to synthesis in the body– Although some are chemically similar to each

other, there is no common chemistry of vitamins

Vitamin Nomenclature:

• Vitamins were originally categorized as:– Fat soluble: extractable with lipid solvents

• vitamins A, D, E, K

– Water soluble: extractable in water solution• vitamin C and the B-complex group

Vitamin A:

• Functions - regeneration of visual purple, essential for normal epithelial tissue

• Deficiency symptoms - night blindness, keratinization of epithelium, xeropthalmia

• Major sources - yellow corn, alfalfa, liver, fish liver oils

• Precursor - carotene

Vitamin D:

• Functions - calcium and phosphorus absorption and metabolism

• Deficiency symptoms - rickets, osteomalacia, decreased egg laying

• Major sources - cured hay, fish liver oils, irradiated yeast, milk fat, egg yolk

Vitamin E:

• Functions - antioxidant, normal reproduction and hatchability

• Deficiency symptoms - infertility in some species, skeletal muscular dystrophy, exudative diathesis, encephalomalacia, liver necrosis

• Major sources - germ of cereal grains, egg yolk, oilseed oil, alfalfa

Vitamin K:

• Functions - prothrombin formation for normal blood clotting

• Deficiency symptoms - hemorrhages in various tissues

• Major sources - green, leafy plants; liver; egg yolk; fish meal

Vitamin C (ascorbic acid):

• Functions - formation and maintenance of intercellular material

• Deficiency symptoms - scurvy, bleeding gums, anemia

• Major sources - citrus fruits; tomatoes; green, leafy vegetables

• Note - generally not a dietary requirement for domestic animals

Thiamine (B1):

• Functions - essential in carbohydrate metabolism and energy transfer

• Deficiency symptoms - lack of appetite, beriberi in humans, polyneuritis in birds, reproductive failure in horses

• Major sources - milk products, brewer’s yeast, cereals and their byproducts, liver

Riboflavin (B2):

• Functions - energy transfer, protein metabolism

• Deficiency symptoms - lesions of skin, eye, and nervous system; depressed appetite; curly toe paralysis in chickens

• Major sources - milk, cheese, liver, kidney, eggs, fish, green forages, oil meals

Pantothenic Acid:

• Functions - metabolic reactions as a component of coenzyme A

• Deficiency symptoms - retarded growth, skin lesions and depigmentation, goose-stepping in pigs

• Major sources - cereal grains and their byproducts, liver, egg yolk, milk, alfalfa

Nicotinic Acid (niacin):

• Functions - energy transfer

• Deficiency symptoms - pellagra (black tongue), dermatitis, diarrhea, dementia, loss of appetite and weight

• Major sources - milk, meat, eggs, green vegetables, peanut butter, animal and fish byproducts

• Note - can be partially spared by tryptophan

Pyridoxine (B6):

• Functions - protein metabolism

• Deficiency symptoms - dermatitis in pigs and poultry, anemia in puppies and pigs

• Major sources - yeast, liver, meat, egg yolk, milk, cereal grains, vegetables

Biotin:

• Functions - fat synthesis, deamination of amino acids

• Deficiency symptoms - dermatitis, loss of hair, nervous system disturbances, perosis in chicks

• Major sources - whole grains, milk, yeast, organ meats

Folic Acid:

• Functions - synthesis of purines and certain methyl groups, erythropoiesis

• Deficiency symptoms - retarded growth, anemia, poor feathering

• Major sources - green, leafy vegetables; organ meats; cereals; soybeans; animal byproducts

Cyanocobalamin (B12):

• Functions - carbohydrate and fat metabolism, nucleic acid synthesis

• Deficiency symptoms - retarded growth, low hatchability of eggs, uncoordinated gait, anemia in humans

• Major sources - milk, meat and animal byproducts, fish meal

Choline:

• Functions - maintenance of cell structure, fat metabolism in liver, transmission of nerve impulses

• Deficiency symptoms - fatty liver, renal tubule degeneration, enlarged spleen, kidney hemorrhage

• Major sources - milk, meat eggs, fish, fats

Related: Inositol

• Functions - lipotropic action in rat diets in which other vitamins are deficient

• Deficiency symptoms - alopecia

• Major sources - phytin in plant products

Related: Para-aminobenzoic Acid

• Functions - growth stimulant in chicks; anti-gray hair factor in rodents

• Deficiency symptoms - graying hair in animals other than humans

• Major sources - a synthetic product

Vitamin Expression:

• Vitamin potency is expressed in two ways:– Activity: International Units (IU) are the units

of expression, defined as the activity created (example: growth) by a particular amount of a vitamin. Example: 0.3 micrograms of crystalline vitamin A alcohol = 1 IU

– Weight: most B-complex vitamins are reported in supplements by weight. Example: niacin reported as 5mg/lb of a feedstuff

Vitamin Assays:

• Biological assay- feeding known amounts of vitamins to vitamin-depleted animals and assessing performance

• Microbiological assay - using microbes as test subjects in a biological assay method

• Chemical assay - determination of concentration based upon analysis for specific chemical characteristics