Fat soluble vitamines

transcript

Fat soluble Vitamins(A, D, E, K)

Vishnu Vardhan Reddy.PTVM/2015-29

What are vitamins

• Vitamins are tasteless organic substances that are

indispensable to the normal metabolic processes of

organisms. They are essential to maintain health and

performance, and have to be supplied with the feed.

• Vitamins do not provide energy themselves, but a

deficiency of any vitamin can cause serious symptoms.

History

• The term vitamin was coined by biochemist

Casimir Funk.

• In 1912 When scientists trying to isolate fat soluble

factor B, they discovered a substance containing

nitrogen which was chemically an amine, and which

was in therefore named vitamin (vita = life).

Classification of vitaminsThere are two main groups of vitamins:

• Fat-soluble vitamins:

Fat-soluble vitamins have specific functions

in the development and maintenance of tissue structures.

• Water-soluble vitamins:

Water-soluble vitamins participate in

catalytic functions or act as control mechanisms in the

metabolism, e.g. as co-enzymes.

Fat soluble vitamins• The vitamins A, D, E, K and ß-carotene (precursor of

vitamin A) belong to the fat-soluble vitamins.

• These are stored in the body for long periods of time

and generally pose a greater risk for toxicity when

consumed in excess.

• The sites of storage are inner organs such as the

kidneys and liver, the muscles, the brain and fat tissue.

• In the small intestine, the fat-soluble vitamins are

transported into the intestinal cells as part of micelles.

• Once inside the intestinal cells, fat-soluble vitamins are

packaged with fat and other lipids into a chylomicron.

• The chylomicrons travel through the lymph system to

the main circulation.

• Excretion normally only occurs after transformation

during metabolism.

Vitamin A

• Vitamin A was discovered in 1909 in fish liver oil

• The term vitamin A refers to a family of fat-soluble

retinoids that include retinol, retinal, and retinoic acid.

• They contain a ring with a polyunsaturated fatty acid

tail. Attached at the end of the fatty acid tail is either an

alcohol group (retinol), an aldehyde group (retinal), or

an acid group (retinoic acid).

Vitamin A terms

• Retinoids The term used to describe the family of preformed

vitamin A compounds.

• Retinol The alcohol form of preformed vitamin A.

• Retinal The aldehyde form of preformed vitamin A.

• Retinoic acid The acid form of preformed vitamin A.

• Retinyl ester The ester form of preformed vitamin A found in

foods and stored in the body.

• Beta-carotene One of the provitamin A carotenoids.

Natural sources and bioavailability

• Vitamin A is found only in feeds of animal origin, e.g.

liver, fish oil and high-fat fishmeal

• Low in milk and eggs.

• Feeds of plant origin (grass, carrots) only contain ß-

carotene, a precursor that can be converted into

vitamin A.

• Conversion ratio of ß –carotene into vitamin A

depending on animal species

Species

Vitamin A per mg beta Carotene

Conversion ratio

Dairy cows 370 IU 8–10 : 1

Fattening cattle 440 IU 7–8 : 1

Horses 420 IU 6–10 : 1

Sheep 480 IU 6–8 : 1

Pigs 510 IU 6–7 : 1

Poultry 1667 IU 2 : 1

Conversion of Vitamin A Compounds

Retinyl ester Retinol (alcohol form) Retinoic acid Retinal (aldehyde form)

Beta-carotene

Metabolic Functions of Vitamin A

• Each form of retinoid plays a specific role in the body.

Retinal (the aldehyde form) participates in vision.

• The hormone like action of retinoic acid (the acid form) is

essential for growth and development of cells, including

bone development.

• Retinol (the alcohol form) supports reproduction and a

healthy immune system. In addition to these critical

roles, vitamin A may help prevent cancer.

Physiological role of vitamin A

• Formation, protection and regeneration of skin and

mucous membranes

• Promotion of fertility

• Control of growth and differentiation processes of the

cellular metabolism

• Increased resistance to infectious diseases

Interaction with other nutrientsVitamins Synergistic to Vitamin A

• Vitamin E & Vitamin C : Due to their antioxidant

activity. And vitamin E aids in stabilization of cell

membranes.

• Vitamin B6 : Because of its synergistic effect upon the

mineral zinc.

• Besides B6, vitamin B1, B2, B3, and B5 have been

specifically described as vitamin A synergists.

Vitamins Antagonistic to Vitamin A

• Fat soluble vitamins compete for absorption and transport

so all other fat soluble vitamins are antagonistic In nature.

• Vitamin E : The antagonistic effects are also indicated by

the opposite effects on prostaglandin E1 and E2 (PGE2

PGE2) synthesis.

• Vitamin C : Due to its copper lowering effect, causes

oxidation of vitamin A by increasing tissue iron

accumulation.

• Vitamin B1, B12, B6.

Minerals Synergistic to Vitamin A

• Zinc : Required for the mobilization of vitamin A from

liver. Zinc is involved in maintaining the plasma retinal

binding protein (RBP), a specific transporter for vitamin A.

• Iron : Vitamin A facilitates the mobilization of stored iron

for incorporation into erythrocytes.

• Selenium : Involved in antioxidant activity.

• Magnesium, Manganese, Potassium, and Phosphorus.

Minerals Antagonistic to Vitamin A

• Iron : Excessive tissue causes destruction by

peroxidation.

• Selenium : Though selenium is an antioxidant, in large

amounts it acts as a pro-oxidant.

• Iodine : In the form of T4, although synergistic to

vitamin A, is antagonistic as well.

• The minerals copper, calcium, and sodium can have an

indirect antagonistic effect upon vitamin A due to their

interrelationship with the thyroid gland

Requirements• For dogs and cats (RE Per Kg of feed 1 RE=40,000 IU)

• For Sheep and Goat (IU Per Kg of feed)

Species Weaning(RE) Adult(RE) Peak lactation(RE)

Dog 1515 1515 1515Cat 1000 1000 2000

Species Growing lambs/Kids

Growing ewes

Lactating ewes

Sheep 1567 3305 2667Goat 1530 1530 1532

• For Cattle (IU Per Kg feed)

• For Chicken (IU Per Kg feed) 1500 (for all types)

Type Feedlot Cattle Pregnant heifer & cow Lactating cow

Beef 2200 2800 3900

Type Lactating cows Fresh cows Dry pregnant

cowsGrowing pregnant

heifers

Dairy 2123-3685 3490-5540 5576-8244 6486-7075

Deficiency symptoms

• Cornification of skin and mucous membranes.

• Retarded maturation of the ova and embryo mortality.

• Increased risk of infections.

• Nervous lesions.

• Night blindness.

• Xeropthalmia.

• In commercial supplement of vitamin A The active

substance of these products is vitamin A acetate.

The standard vitamin A content is normally 500 000 IU/g.

Excretion:

Most in urine as Oxo retinoic acid, small amounts in

expired air, some in feces.

Toxicity:

Birth defects, Central nervous disorders, Liver

abnormalities, Loss of bone density.

Vitamin D

• Vitamin D3 was discovered in 1918 in fish liver oil

• Vitamin D (calciferol) is called the “sunshine vitamin”

because it is derived from the reaction between

ultraviolet (UV) rays and a form of cholesterol found in

the skin.

• Vitamin D is found in two forms.

• Cholecalciferol or vitamin D3 is the form produced in

the skin and found in animal foods.

• Ergocalciferol or vitamin D2 is found in plants and

dietary supplements.

• Ergocalciferol and Cholecalciferol differ chemically in

the structure of their side chains.

• Vitamin D is found in very few products, e.g. as vitamin

D3 (Cholecalciferol) in whole milk and liver oils, and as

vitamin D2 (Ergocalciferol) in sun-dried green forage.

• Vitamin D2 is formed under the influence of UV

radiation from ergosterol in plants when they are

dried. Vitamin D3 is formed in the epidermis from 7-

dehydrocholesterol by UV radiation (exceptions: dogs,

cats).

Metabolism of Vitamin D

7-dehydrocholesterol Previtamin D3

Calcidiol Cholecalciferol

Calcitriol

Physiological role of vitamin D• Vitamin D3 has no direct metabolic activity 1,25-

dihydroxyvitamin D3 is the form with the largest

biological effect.

• It regulates calcium and phosphate absorption and

metabolism and controls blood pressure.

• It promotes germ cell production

• It increases the performance of the immune system,

and inhibits auto-immunisation.

Interaction with other nutrients

• Magnesium : It activate vitamin D into a biologically

active form, and required to maintain calcium in the

body and is essential for bone health.

• Vitamin K : It helps in calcium absorption from foods.

And also helps in strengthening of bones.

• Zinc : Hepls in absorption of vitamin D into the cells.

• Boron : Hepls in absorption of Ca by bones.

• Vitamin A : Vitamin A and vitamin D work together for

animal health.

• Calcium : Low levels of vitamin D causes decreased

calcium absorption.

• Phosphorus : Ca and P ratio is important for vitamin D.

• Vitamin E : May cause vitamin -D dependent bone

mineralization problems.

Requirements

• For dogs and cats (RE Per Kg of feed 1 RE=40,000 IU)

Species Weaning(RE) Adult(RE) Peak lactation(RE)

Dog 13.8 13.8 13.8Cat 5-6 7 7

Growing ewes

Lactating ewes

Sheep 84 98 67Goat 136 136 136

• For Chicken (IU Per Kg feed) 200 (for all types)

Beef 275 275 275

heifers

Dairy 600-685 951-1511 1520-2249 804-858

Deficiency symptoms

• Disorders of calcium and phosphate metabolism.

• Rickets in young animals & Osteomalacia in adults.

• Extraction of mineral substances from the bones.

• Deformed bones and joints (softening of the bones).

• Growth disorders.

• Spontaneous bone fractures.

• Poor eggshell stability.

• Commercial supplement of vitamin D formulations

normally have a vitamin D3 content of 500 000 IU/g.Toxicitykidney damage, Nausea, Weakness, Disorientation.

Excretion

• Bile > feces > urine

Vitamin E

• Vitamin E was discovered 1922 in wheat germ oil.

• There are eight different forms of naturally occurring

vitamin E, but one form, alpha-tocopherol (α-

tocopherol), is most active in the body with a side

chain of saturated carbons.

• Grass, clover, alfalfa, green meal and uncrushed

oilseeds are rich in vitamin E.

• Humidity and long storage have an adverse effect on

vitamin E stability and content.

• Cereals and middlings mainly contain Beta, gama and

delta tocopherols (70–90%) with a biological activity

significantly lower than that of alpha tocopherol.

Physiological Role• Reduces the production of lipid peroxyl radicals from

highly unsaturated fatty acids.

• Antitoxic effect in cell metabolism.

• Reduces the incidence of liver necrosis and muscular

degeneration.

• Antioxidant effect and .

• Stabilization of fat (protection against oxidation) in

animal products (meat, milk, eggs).

• Controls metabolism of the hormones via the anterior

lobe of the hypophysis.

• Maintains membrane stability, especially of the cardiac

and skeletal muscles.

• Controls the development and function of the gonads.

• Stimulates antibody production, phagocytosis and the

bactericide effects of phagocytes.

• Protection against abortion.

Nutrients Synergistic to Vitamin E

• Selenium : Function closely linked to vitamin E (needed for GSH peroxidase).

• Vitamin C : Helps in anti oxidant property.

• Sulfur containing amino acids.

Nutrients antagonistic to Vitamin E

• Vitamin A : Vitamin E Inhibits carotene absorption and

conversion to retinol.

• Vitamin K : May impair absorption.

• May cause vitamin -D dependent bone mineralization

problems.

Requirements• For dogs and cats (mg Per Kg of feed)

Species Weaning(mg) Adult(mg) Peak lactation(mg)

Dog 30 30 30Cat 38 38 31

Growing ewes

Lactating ewes

Sheep 15 15 15Goat - - -

• For Chicken (IU Per Kg feed) 10-5 (for all types)

Beef - - -

heifers

Dairy 16-27 39-35 81-120 80-113

Deficiency symptoms• Damage to cardiac and skeletal muscles (dystrophy,

myopathy)

• Sudden death through damage to the heart muscle

(mulberry heart disease)

• Liver lesions and changes in fat deposits (yellow-fat

disease in mink, brown coloration of bacon).

• Locomotory disorders and muscle incurvation (banana

disease) in pigs.

• Stiff lamb disease and White muscle disease due to

dystrophic alteration in calves and lambs.

• Fertility disorders

• Changes in the vascular and nervous system.

• Exudative diathesis.

• Nutritional encephalomalacia.

• Reduced hatchability and exudative diathesis

(increased plasma secretion of the blood) in poultry.

Toxicity

• There isn’t any known risk of consuming too much

vitamin E from natural food sources.

• Because vitamin E can act as an anticoagulant and

interfere with blood clotting, excess amounts in the

body increase the risk of hemorrhage.

Vitamin K

• Vitamin K was discovered in 1929 in alfalfa

• Vitamin K is a generic term for vitamin K1

(phylloquinone), K2 (menaquinone) and K3 (menadione).

• Green plants are rich in vitamin K1, Vitamin K2 is

produced by bacteria in the rumen and in the large

intestine.

• Vitamin K3 (menadione) is an industrial form.

• The fat-soluble forms K1 and K2 can only be absorbed

when pancreas lipase and bile acid are secreted.

• This is not necessary for the water-soluble vitamin K3.

• All three forms serve as a basis for the production of

menaquinone-4, which is highly active in the

metabolism.

Physiological role

• Synthesis of blood coagulation factors II (pre-

thrombin), VII, IX and X.

• Production of the calcium transport protein

osteocalcin for bone mineralization Participation in

carboxylation of other proteins.

• Vitamin A & Vitamin E : May reduce the absorption of

Vitamin K.

• Vitamin E : interfere with blood clotting mechanism of

Vitamin K.

Requirements• For dogs and cats (mg Per Kg of feed)

• For Chicken (IU Per Kg feed) 0.5 (for all types)

Species Weaning(mg) Adult(mg) Peak lactation(mg)

Dog 1.64 1.63 1.60Cat 1 1 1

heifers

Dairy 2200 2200 2200 2200

Deficiency symptoms• Hemorrhages in various tissues and organs.

• Blood coagulation disorders.

• Growth disorders.

Antagonists• Dicoumarol.

• Coumarin derivatives.

• Sulphonamides.

• Mycotoxins.

Commercial supplement of vitamin K

Vitamin K3 is offered in three different product forms:

1. Menadione sodium bisulphite (MSB), with a minimum

content of 50% menadione

2. Menadione pyrimidinol bisulphite (MPB), with a

content of approx. 23% or 43% menadione

3. Menadione nicotinamide bisulphite (MNB), with a

content of 23% or 43% menadione and 16% or 31%

nicotinamide

Toxicity

• Occurs rarely.

• Vitamin K, excessive amounts can cause the

breakdown of red blood cells and liver damage.

THANK YOU

Vishnu Vardhan Reddy.PTVM/2015-029

Fat soluble vitamines

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