Vitamins

• chemically not related organic compounds which cant be synthesized by humans in appropriate amount

  
  

• essential compounds -> must be taken by food

• partly formed by bacterial flora of GIT (not appropriate amount)

• water soluble (C + B-complex)

• fat soluble (A, D, E, K)

1) Enerergy Metabolism: B1, B2, B3, B5, B7

2) Hematopoiesis: B9, B12

2) Other (Amino Acid Metabolism: B6, Pyridoxal, Pyridoxamine

1) Reduced Intake

2) Increased Requirement + Utilization

• pregnancy, lactation, growth

• infectious disease

• alcoholism

3) Defects of Absorption

• disease of intestinal mucosa + decreased bile secretion

4) Effects of Drugs

• antivitamins + supression of intestinal bacterial flora

5) Liver Disease

• decreased capacity of storage + decreased activation

substances that decrease or interrupt the effect of vitamins

• enzymes which decompose the vitamins —> thiaminase, ascorbase

• substances forming complexes with the vitamins —> avidine

• substances structurally similar to vitamins —> sulfonamides

• retinol (retinyl ester) —> animals

• b-carotene —> plants

Cholecalciferol

Phylloquinones (K1) —> plant origin

Menaquinone (K2) —> product of intestinal bacteria

Tocopherols

• retinol

• retinal

• retinoic acid

• vision

• reproduction

• growth

• maintenance in epithelial tissue

• Treatment of severe Acne

• treatment of psoriasis

• treatment of promyelocyitc leukemia

• maintenance of reproduction

• maintenance of vision

• promotion of growth

• differentiation + maintenqance of epithelial tissue

• gene expression

• night blindness

• anaemia

• increased keratinization

• defects in regeneration of skin + mucosae

• infections

• Skin —> dry due to decrease in keratin synthesis

• Liver —> becomes enlarged and maby cirrhotic

• NS —> a rise in intracranial pressure (may mimic symptoms of brain tumor)

• congenital malformations —-> in the developing fetus

a-tocopherol

• antioxidant —> protection of membrane phospholipids against free radicals

• activates delta-ALA-synthase

• activates cyclooxygenase

• fragility of Erythrocytes

• neurological symptoms

• anaemia in newborns

• damage of muscles

1,25-dihydroxycholecalciferol (1,25-diOH-D3)

maintenance of physiological concentration of Calcium in plasma

• increases uptake of calcium + phosphate by the intestine

• stimulates resorption of bone when necessary

• minimizes loss of calcium by the kidney

• Rachitis —> in children

• Demineralization of bones —> in adults

Calcification of tissues (pancreas, myocard,..)

K1 —> phylloquinone (plant origin)

K2 —> menaquinone (product of intestinal bacteria)

regulation of blood coagulation

• in liver increases formation + secretion of prothrombin

• participates in activation of prothrombin to thrombin

  
  

rare —> with respect to content in food + synthesis by mucosal flora

• bleeding to skin, mucosa, muscles, organs

  
  

• intestine of newborns is “sterile” —> no bacterial flora that produces Vit. K

• newborns are treated with intramuscular dose of vitamine K as a prevention of bleeding

Ascorbic Acid

ascorbic acid

reducing agent as coenzyme (especially in hydroxylation reactions):

• dopamine-b-hydroxylase (monooxygenase) - noradrenalin formation

• posttrandlation modification of proline (hydroxylation of proline at collagen sythesis)

• hydroxylation of corticoids at cholesterol degradation

• maintenance of Fe2+ - hemoglobine, absorption of Fe

• Scurvy

• defects in connective tissue (symptoms explained by deficiency of hydroxylation of collagen)

Thiamine

Riboflavin

Niacin

Pantothenic acid

Pyridoxin

Biotin

Folic acid

Cobalamin

thiamine pyrophosphate

• thiamine diphosphate (TDP)

• thiamine triphosphate (TTP)

coenzyme

• pyruvate dehydrogenase

• 2-oxoglutarate dehydrogenase

• transketolase

activates CL- channels —> transfer of nerve excitation

• pentose phosphate pathway

• PDH complex

• Krebs cycle

Beri-Beri:

• nerve: inflammation, changed-reflexes, degenerative changes of central + peripheral nerves, paralysis, muscle pain

• cardiovasculat system disorder

• fatigue, anorexia

Wernicke-Korsakoff Syndrome (WKS):

• is usually secondary to alcohol abuse deficiency of thiamin —> characterized by apathy, loss of memory, atacia or nystagmus

• flavin mononucleotide (FMN)

• flavin adenine dinucleotide (FAD)

• coenzyme of oxidation -reduction reactions —> part of dehydrogenases, oxidases

• in the process of terminal oxidation, synthesis and degradation of fatty acids

• skin disorder

• inflammation of corners of mouth

• corneal injury

• thrombodis

• artheroslerotic changes

• as isolated deficiency its rare

• associated with deficiency of other B vitamins

• nicotinamide adenine dinucleotide (NAD+)

• nicotinamide adenine dinucleotide phosphate (NADP+)

coenzyme of redox reactions —> part of dehydrogenases

• as isolated deficiency its rare

• associated with other deficiency of other B vitamins

Pellagra

• damaged function of skin, mucosa + CNS

• inflammation of GIT

• blood diarrhea

• CNS disorders

• visual disturbance

• loss of memory

The 3 Ds

• dermatitis

• diarrhea

• dementia

part of coenzyme A

• as a part of CoA it has a central function in metabolism

• activation of molecules before their entrance into metabolic pathways (acetylCoA, acylCoA)

• is rare

may include:

• fatigue

• depression

• irritability

• vomiting

• stomach pains

• upper respiratory infections

• burning feet

Pyridpoxal phosphate (PLP)

is coenzyme of enzymes

• transaminase, decarbocxylase, aldolase

• enzymes of AA synthesis

• release + fixation of ammonia

• cystationine synthase

• inflammation of skin + mucosa

• hyperpigmentation

• CNS disorders —> depression + excitability and inflammation of nerves

connected with increased excretion of some AA metabolites by urine

is activated after it is bound to an enzyme

coenzyme of carboxylations

• rare

• depression

• inappetence

• muscle pain

• skin inflammation

Tetrahydrofolate (THF)

transport + utilization of one-carbon residues (from Serine, Glycine, His, Trp) —> which then will be used in the processes of:

• de novo synthesis of purines (2nd+ 8th carbon atom)

• synthesis of pyrimidine (methylation of dUMP to dTMP)

• conversion of Homocysteine to Methionine

• tRNA methylation

Megaloblastic anemia

• due to reduced synthesis of purines + dTMP —> results in inabiloty of cells (including RBC precursors) to synthesize DNA —> the cells can not divide

• + disorder of bone growth and a decrease in number of leukocytes and platelets

• fatigue

• shortness of breath

• diarrhea

• headaches

  
  

• methyl cobalamine

• deoxyadenosyl cobalamine

• intake of Vit. B12 by food

• Vit. B12 binds to intrinsic factor in intestine

• cobalamine-intrinsic factor compley travels through gut —> binds to specific receptors on surface of mucosal cells in ileum

• bound cobalamin is transported into the mucosal cell —> gets into blood circulation

caused by a lack of intrinsic factor —> Vit B12 can not be absorbed

coenzyme of enzymes

• methionine synthase

• methylmalonyl-CoA mutase

• methyl folate trap

• methylmalonyl-CoA cant change into succinyl-CoA (KC) due to lack of B12 (methylmalonyl-CoA mutase)

• decreased synthesis of new purines due to defficiency of Vit. B12 + Vit. 9

• decreased methylation of dUMP to dTMP

• increased homocystein + decreased methionine

• cardiovascular system -> elevated homocytein levels lead to depositing in the walls of blood vessels —> atherosclerosis (especially if cholesterol is also elevated)

• Megaloblastic anemia

CNS disorders

• a lot of methylmalonyl-CoA leads to a competition with malonyl-CoA in the synthesis of branched fatty acids —> damage of myelin structure

• elevated homocystein (serum, urine)

• elevated mathylmalonate (urine)

• decreased number of Leukocytes + Thrombocytes

• inflammation, ulceration (reduction of cell division)

• reduced methionine -> reduced choline -> reduced production of acetylcholine