66 - VITAMINS Vitamin Classification Fat soluble vitamins...

Info iconThis preview shows pages 1–16. Sign up to view the full content.

View Full Document Right Arrow Icon
VITAMINS VITAMINS
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Vitamin Classification Vitamin Classification Fat soluble vitamins A, D, E, K Water soluble vitamins Vitamin C B-complex vitamins Thiamine (B1), Riboflavin (B2), Niacin, B6, B12, Folic Acid, Choline, Pantothenic Acid, Biotin
Background image of page 2
This diagram shows the metabolic cycles, showing where vitamins are involved.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Vitamin A Vitamin A 3 forms Retinol Retinal Retinoic acid Precursor: Carotene Functions: Protects epithelial tissues + ++
Background image of page 4
Vitamin A Structure Vitamin A Structure
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Vitamin A Vitamin A A.Introduction 1.Chemically known as retinol 2.It is an unsaturated monohydric alcohol with the shown structural formula:
Background image of page 6
3. It is a pale yellow crystalline solid, insoluble in water, but soluble in fats and various fat solvents. 4. It is readily destroyed by oxidation on exposure to air and light. 5. Vitamin A does not occur in plants but rather as its precursor, carotene , or carotenoid pigments.
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Sources of Vitamin A Sources of Vitamin A 1. Liver is a rich source of vitamin A. 2. Egg yolk and milk fat are generally rich sources. 3. Green forages, well-made hays and legume-grass silages are good sources. 4. Grains, except corn, are low or devoid of vitamin A activity. 5. Animal products are poor sources.
Background image of page 8
1. Provitamins a. Includes α -, β - and γ - carotene and cryptoxanthin b. Most important is β -carotene a. red in color b. green feeds are excellent sources c. Conversion to vitamin A a. Occurs in intestinal wall and liver and possibly in the kidney and lung b. In theory one molecule of carotene should yield two molecules of A c. Efficiency is below the expected.
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Vitamin A value is defined as One I.U. of vitamin A = vitamin A activity of 0.300 ug of crystalline vitamin A alcohol
Background image of page 10
Efficiency of conversion Efficiency of conversion Species β - carotene Vit A, I.U. Rat 1000 1667 Poultry 1000 1667 Beef cattle 1000 400 Sheep 1000 480 Swine 1000 533 Dairy cattle 1000 400 Horses 1000 555 to 333 Dogs 1000 833
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Metabolism Metabolism Vitamin A and vision Rhodopson (visual purple), the pigment of the rod cells of the retina of the eye, is made of the vitamin plus a protein moiety. When exposed to light, the pigment breaks down into its constituents and these chemical changes are accompanied by stimulation of the optic nerves. Rhodopsin is regenerated in the dark.
Background image of page 12
Ability to see in dim light depends on the rate of resynthesis of rhodopsin. Rhodopsin formation is impaired where vitamin A is deficient
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Other tissues Other tissues Maintains mucous membranes of the respiratory tract, intestinal tract, urethra, kidney and eyes in a healthy condition In absence of vitamin A, they become keratinized and susceptible to infection Role in bone formation
Background image of page 14
Vitamin A Deficiencies Vitamin A Deficiencies Night Blindness Xeropthalmia Infertility, abortion, fetal abnormalities Metaplasia (change of cell type) Infections Dozens of other symptoms, as Vit A is involved all over the body
Background image of page 15

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 16
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/09/2010 for the course ANSC 221 taught by Professor Staff during the Spring '08 term at Purdue University-West Lafayette.

Page1 / 96

66 - VITAMINS Vitamin Classification Fat soluble vitamins...

This preview shows document pages 1 - 16. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online