146
18703011811795””
“”17701728~1779“”

Christian Eijkman (Ducth) found Vit.B1 ( Nobel Prize for Medicine and Physiology ,1929)
Albert Szent-Gyorgyi (Hungarian) found Vit.C ( Nobel Prize for Medicine and Physiology ,1937)
Dam (Dane) found Vit.K ( Nobel Prize for Medicine and Physiology ,1943)

Concept
vitamins are chemically unrelated organic compounds that cannot be synthesized in adequate quantities by humans and, therefore, must be supplied by the diet.
Vitamin

Characteristics
1. neither the component of the organization nor the energy material
2. the requirement is limited.
3. It can not be synthesized by humans (or a little), and must be supplied by diet

Water-soluble Vitamin
B-Complex vitamin, Vitamin C
B-Complex vitaminBl, B2, PP, B6, pantothenic acid , biotin, Folic acid, B12 , etc.
Classification:

1Lipid soluble
2They are released, absorbed and transported with the fat of diet
3They are transported with lipoproteins or some special binding proteins in blood
4They are stored in the liver and adipose tissue.
Types Vit A, Vit D, Vit E, Vit K

(1) Natural forms
(2) Active forms
Retinol, retinal, retinoic acid
A1——Retinolmainly exists in livers of mammals and seawater fish;
A2——3-dehydrogenation retinolmainly exists in livers of freshwater fish.

C
H
2
O
H
15
15
2. Function and deficiency diseases
(1) It is a component of the visual pigments of rod and cone cells
Rod cells Rhodopsin opsin 11-cis retinal
Deficiency diseases:
Night blindness
Deficiency diseases:
Darier disease
Xerosis cutis
(2) It is essential for normal differentiation of epithelial tissues and mucus secretion.
Xerophthalmia


VitD3 in animal tissue
. Vitamin D
Vit D3

(1) Maintain adequate plasma levels of calcium
2. Function and deficiency diseases

D D
VD“”“”xi “”“”“”“”“”“O”“X”“” VDVD20-301VDVDVDVD7-VD10VDVD600-80060015VD400-800VD3---5VDVDVAVD

High doses can cause loss of appetite nausea , hypercalcemia , etc.
(4) Toxicity of vitamin D

and

(1) Antioxidation
(2) Prevent and cure the threatened abortion and habitual abortion
deficiency diseases: sterility

It is required in the synthesis of prothrombin and blood clotting factors.
(3) Sources

Water-soluble and readily excreted in the urine.
They must be absorbed from the food frequently and can not be stored.
They are precursors of coenzymes for the enzymes.
TypesB-Complex vitamin, Vitamin C
Common characteristics
( TPP)
TPP
(thiamine)

deficiency diseases: beriberi

(2) TPP is the coenzyme for transketolase in pentose phosphate pathway.
deficiency diseases: indigestion


meat, etc
(3) Sources:
2. Function and deficiency diseases
FMN and FAD are the prosthetic group for oxidation-reduction enzyme, which can reversibly accept two hydrogen atoms.

nicotinamide

2. Function and deficiency diseases

acyl carrier protein


4-

CoA
AMP

They are the coenzymes for acyltransferase.

(1) Types
Biotin deficiency does not occur naturally because it is widely distributed in food. It also can supplied by intestinal bacteria in humans.
(2) Sources

(2) It takes part in signal transduction and gene expression
2. Function and deficiency diseases

(1) Types
(1) Pyridoxal phosphate is the coenzyme for aminopherase and decarboxylase.
(2) Pyridoxal phosphate is the coenzyme for ALA synthase.

(3) Pyridoxal phosphate is the coenzyme for enzyme of hyperhomocysteinemia catabolism.
deficiency diseases:
Dihydrofolate reductase
(2) Sources
In liver
2. Function and deficiency diseases
FH4 plays a key role in one-carbon metabolism, is essential for the biosynthesis of nucleic acid.
deficiency diseases: megaloblastic anemia
1. The chemical natures and properties
(2) Active forms:
It plays key roles in methyl transfer and one-carbon metabolism.
deficiency diseases:
megaloblastic anemia
1. The chemical natures and properties
(3) Sources

(2) Participate in the transformation of cholesterol;
(3) Protect sulphur enzyme can not be oxidated;
(4) Combined with the heavy metal ions and ruled out of the body.
2. Function and deficiency diseases
Scurvey