Vitamins Types - Lecture Note

Vitamins are organic compounds chemically un related structures I Fat Soluble vitamins: (A.Κ.Ε.D) Vitamers: Retinol alcohol inter conversien oxidation Reduction seductase + by Retinal NADH or NADPH animal Retinyl Eshr Essential [Not synthesized by Hunan body] Supplied by Diet • Vitamin A: [Retinol or anti Night Blindness] →an containing Brianone Ring all called [Retinoids Active forms required in trace (small) amount. Functions: wald's visual cycle: Rhodopsin sis Retinal • Sources, absorption & transport opsin intestinal lumen Diet s.intesloe cells opsin cis rekinal Plant 8. corotene 8. Cantene Be Wael 2 Retinal ↓ cis inal Rehmal (Samprase Retinal Retinaldehyde Rehnol Retinol oxidation Fatty esteriled Retingl esters Retinoic acid Acid Can not be reduced in Not converted back to Retina body or retinol [imeversible] PRBP Re kinal Rekool. RBP found in plant B. Carotene Pro-vitamin A food eng cairots. cleaved by Dioxygenase enzyme (oxidatively cleaved) in the intestine to yield two molecules of (Retinal) agrade Receptns all trens inal Rekosl Reknyl Grier chylomicron Stered in liver -Retina/skin/Ganeds CRBP (ceptalar Betinal binding paleio) chinel stored in Reine Growth vitamin A ecrelerate Mind growth of Bone & teeth. vit growth rate & Bone development also slowed. Maintenance of hea thy epithelial alls ing for differentration (Mainly Retinaic Rou) Reproduchon (Retinal & Retinal) supportking spermatogenesis in mole e preventing fetal resumption in female vitamin has antioxidant activity. thenpeutic uses of vitamin As treatment of Psoriasis: tretinoin Call trans Rekineic Acid) treatment of severe acne isotretimin (13 cis chinoic Acid) Vitamin K: Fanti haemorrhage Kongulation vitunin Coagulation Vitamin evitamers: & Sources: Vitamin K. [phylloquinene 20 C. Plant souwres naphthoquinone derivative with Lang isoprenoid side chain vitaan ka [Menq quinone 30c synthesized by intestinal Bacteria Vitamin K3 [mena dione water Soluble, Synthetic vitamin • after absorption with Chylomicron transported with [B. lipoprotein]. • Biochemical importance : Avitamin k is necessary for Congulation, Formation of r. Carboxy glutamate: Vit.k is required in the hepatic synthesis of Prothrombin & Bl. clotting factors vitamin k helps the interaction of prothrombin with platelets. polypeptide precessors of clitting factors residue CO vitenin k mm Warfarin/Dicoumarol Mature clothing Fectors W-carboxy w...x Clatang! (Gla) residue Ⓑ synthesis of Osteocalcin in Bones NB Osteocalcin also known as Bone gamma Carbo rygletenic acid containing protein (BGLAP).is a non collagenors protein found in Bene A teeth Deficiency: •is uncommon bic vitamink is widely distributed in green vegetables. & blc intestinal Bact. synthesize it. • impairement of Blood clotting • Haemorrhagic disease of newborn ble newborn has sterile intestine & can not cynthesize vitamin k & mother milk can not give them enough daily requiremmt Causes of Deficiency: Fat Malabsorption new born liver disease Long use of anticoagulant which act as Gompetitive inhibitors for vitenin k. •Taxicity: Hemolytic anemia Jaundice prolonged use of sythebe vit. (Menadione) Can produse hemolytic aneniq Jaundice in infant due to toxic 4 effects on the menbrane of RBC Vitamin D: Cholecalciferol or sun. shine vitamin hormone like funckren Steroid in nature Vitamers: (Sources) steroid Nucleus •Metabolism [Activation & Funckons Shin 7 da hydrocholesterol. Sunlight vit. D Vitamin D₂ Ergocalteal) Found in plant/ desired frin Ergosterol by exposure to sun light er mush.oom Vitamin D3 (Choleakiteal) found in Animal/ derived from 7 dshy dracholesterol (interme dinte in cholesterol synthesis) in demis & epidermis of hwears exposed to sun light (UV) N.B vitamin D absorbed with fat & canied in chylo mican to liver transported in plasma by -globaln vitamin D is Prohormone & its Activation Require 2 hydroxylation Reactions st 25 th positren at liver andy 1st. postion at kidang Levit. DeeDs are not brologically Active but Converted to Active form by hydroxylatren • Active form: 1,25 Dihydroxy cholecalciferol Calcitriol the most prominent action of 1.25 Di (en) D are to regulate plesne levels of & phosphores Liver njer stonge form (tybociant) +Ph Direct Panikyaid gland PTH indirect cat(scalemis) Bene Resophon 1 cat (2) 1 hydmylase Dicer) 1,15 Di (OH) 0, Calcitriol Active form Nimp: Calcitriolt it is the physiological Active forms & it the Bloed catt level Calcitonin peplide harmene released fam thyaid gland & it Bl. Calcium. •Deficiency: Rickets in children: continued Grmation of Collagen matrix of Bone. but incomplete nineralization soft. pliable bone Osteomalaria in Adels: demineralization of preexisting Bone susceptivity to fracture Renal rickets (Renal oster dystrophy) results fan. chanic Renal failue Cinghia Clinical indications: Netritional Rickets Renal os teadystrophy Hypoparethyroidism Causes of Delhings Not exposed to sunlight Malaksuption of D Abnormality of vit D activation St skimphion Binding Palein Colbindan 25 (OH) D3 (calcidrol) is the predominant form of vitamin D in plasma & the mije stonge from of the vitamin. • Toxicity: vit. D is the most toxic vit. enhanced ca absuption & bene resorptren results in hypercalcemia which lead to call deposition in many organs, particularly. asteries & kidneys high doses (100000 10 For appelle nousee thirst & stupor Vitamin A Deficiency : in Eyes: Night Blindness [Nyctalepia is one corlest signs of vitamin A defiviney the visual threshold is increased making it diffrult to see in dim light prolonged deficionry leads to iveversible Loss in the number of visual cells of Dry Cornes (xemphthalmia) in severe de freieng Fissuring of Cornea (Keratomalacia) Bitet's spots (greyish-white area in) Conjunctiva conjunctivitis • Vitamin E.Tocopherol anti fertility Facto are group of organic compounds known as Tocopherols (Chromone ring + iseopreneid side main • Active form: vitamin E consists of 8 naturally orturing tocopherols. of which d. tocopherol (5,7,8 tri methyl tocol) is the most Active. • it must be protected from light. Uv & any oxidation. • it is absorbed along with fat in 5.1 • Bile solts are necessary for absorption - transport by incorporation in VLDL/LDL skin keratinization of cerederna (dry & rough sko) Repeated cough due to decreased Resistance of RT Murasa •Toxicity: provitamin A (B.comtene) tercity is innssible ble conversion of Carstensils to Retinal highly regulated by body homeostatic mechanisme • Functions: try Function of vitamin E is an [anti oxi dant] prevention of non-enzymatic oxide tron of ren components for os. PUFA by mole calar oxygen & free Padicals. • Biomedical importance: Vitamin E is the most powerful natural antioxidant Stabilization of Cmenbrane Regulation of andation Reactions Protection of PUFA & vit. A Vitamin E CA in askaridant acirvity Prefamed vit. A toxicity oners bic efficient absruptren hepatic Storage liver shores e 80% of reseres. • Early sigos of chronic typervitaminosis: Skin dry pruritic liver enlarged & become cirhatic nervous sysh rise in intracranial pressure •may mimic the symptions of Brocs tumors. Bapagnasi women particularly should wot ingest exressive quantities of vit A bic its potestral for causing congmitel Malformations in the fetus. • vitamin E requirement increases as intake of PUFA increases. Deficiency: occurs in premature infant Hemolysis of RBG & anemia due to lacts of protection against Peroxides Muscle Breakdown. Vitamin E Toxicity: Vitamin E is the least toxic of Fiat Saluble vitamins. it may cause tendency to haemorrhage