1. Dr. Noha Soliman

3. Introduction Vitamins Essential nutrients Needed in small amounts for growth, reproduction, and overall health. Vitamins differ from macronutrients- in structure, function and amounts. Vitamins are similar to macronutrients- all are vital to life, organic and available from all food group. Both deficiencies and excesses of a vitamin can affect health.

4. Vitamins are organic nutrients that are required in small quantities for a variety of biochemical functions and which generally cannot be synthesized in the body and must be supplied by the diet

5. Water soluble Fat soluble B complex C or Ascorbic acid A or Retinol D or Cholecalciferol E or Tocopherol K Classification

6. 6

7. Water soluble vitaminsFat soluble vitamins SolubilityWater solubleFat soluble AbsorptionSimpleAlong with lipids Storage*No storageStored in liver ExcretionExcretedNot excreted Excess intakeNontoxicToxic DeficiencyManifests rapidlyManifests slowly TreatmentRegular dietary supplySingle large dose Difference b/w water soluble & fat soluble vitamins VITAMINS

8. B1 - Thiamine B 2 - Riboflavin B 3 - Niacin B 5 - Pantothenic acid B 6 - Pyridoxine B 7 - Biotin B 9 - Folic acid B 12 - Cobalamine Vitamin B complexVitamine C or Ascorbic acid W at er s ol u bl e vi ta m in s VITAMIN S

9. V it a m i n s B - c o m p l e x VITAMIN S

11.  It has a key role in carbohydrate metabolism.  Coenzyme.

12.  Beriberi (means “I can’t, I can’t”) chronic peripheral neuritis which may or may not be associated with heart failure and edema.  Acute pernicious beriberi (shoshin beriberi) in which heart failure and metabolic abnormalities predominate without peripheral neuritis.

14.  The two biologically active forms are flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD).  FMN and FAD are coenzymes in oxidation/reduction reactions.  FMN and FAD are each capable of reversibly accepting two hydrogen atoms, forming FMNH2 or FADH2.  FMN and FAD are bound tightly flavoenzymes that catalyze the oxidation or reduction of a substrate.

15. FMN - Flavin mononucleotide FAD - flavin adenine dinucleotide. Riboflavin is a precursor for FAD and FMN. FAD is a cofactor for pyruvate dehydrogenase complex (PDC), and succinate dehydrogenase in TCA cycle. FMN is an electron carrier in the electron transport chain. Has a central role in energy yielding metabolism.

16.  It is widespread but not fatal.  Characterized by: Cheilosis. (cracks in corners of mouth and lips). Lingual desquamation. (Swollen, reddened tongue). Seborrheic dermatitis.

18. Forms: nicotinic acid and nicotinamide. It can be synthesized in the body from the essential amino acid Tryptophan.

19.  A precursor for the coenzymes nicotinamide adenine dinucleotide (NAD) and its phosphorylated derivative, nicotinamide adenine dinucleotide phosphate (NADP) in oxidation-reduction reactions.  Treatment of hyperlipidemia

21. Pellagra: The Four D’s: (Dermatitis, Diarrhea, Dementia, Death) It is characterized by a photosensitive dermatitis. As the condition progresses there is dementia possibly diarrhea and if untreated death.

23. Part of Coenzyme A which plays an important role in energy metabolism. Is essential for the formation of ATP from the breakdown of carbohydrates, protein, fat. pantothenic acid

26. Pantothenic acid deficiency is a very rare occurrence.

27.  Six compounds have vitamin B6 activity: pyridoxine, pyridoxal, and pyridoxamine, and their 5' - phosphates.  The alcohol form of vitamin-B6 is called pyridoxine (-CH2OH), the aldehyde form pyridoxal (-CHO) and the amine form pyridoxamine (- CH2NH2).

28.  Precursor for the coenzyme pyridoxal phosphate (PLP) which is important in amino acid and glycogen metabolism and in steroid hormone action.  Pyridoxine (B6) is used as anti-emetic drug (prevent vomiting).  Vitamin B6 deficiency is rare.

30.  Biotin is a coenzyme of carboxylase enzymes.  Biotin deficiency does not occur naturally because the vitamin is widely distributed in food.  Also, It is synthesized by intestinal flora in excess of requirements. Note:  the addition of raw egg white to the diet as a source of protein induces symptoms of biotin deficiency.  Raw egg white contains a glycoprotein, avidin, which tightly binds biotin and prevents its absorption from the intestine

31.  Folic acid (folate), which plays a key role in one-carbon metabolism, is essential for the biosynthesis of several compounds.  The need for folate rises considerably during pregnancy and whenever cells are multiplying. folic acid

32.  Coenzyme that transfers single carbons to build larger molecules.  Tetra hydro folate (reduced folate) receives one-carbon fragments from donors such as serine, glycine and histidine and transfers them to intermediates in the synthesis of amino acids, purines, and thymidine mono phosphate (TMP)—a pyrimidine found in DNA.  It helps the body use proteins, builds red blood cells, and forms genetic material.  It prevents birth defects that damage the brain and spinal cord.

33.  Megaloblastic anemia.  Neural tube defects: (Inability of nerve cells to divide and make new cells) Spina bifida Anencephaly

36.  The term vitamin B 12 is used as a generic descriptor for the cobalamins those corrinoids (cobalt containing compounds possessing the corrin ring) having the biologic activity of the vitamin.  Cobalamin may refer to several chemical forms of vitamin B12, depending on the upper axial ligand of the cobalt ion.  These are: Cyanocobalamin (R = –CN) Hydroxocobalamin (R = –OH) Methylcobalamin (R = –CH 3 ) 5'-deoxyadenosylcobalamin (R = –Ado)

37.  Vitamin B12 is a nutrient that helps keep the body’s nerve and blood cells healthy and helps make DNA, the genetic material in all cells.

38.  Pernicious anemia and Neurological problems

41. VitaminCoenzyme 1.Thiamin (B 1 ) 2.Riboflavin (B 2 ) 3.Niacin (B 3 ) 4.Pyridoxine (B 6 ) 5.Biotin (B 7 ) 6.Folate (B 9 ) 7.Pantothenic acid (B 5 ) 8.Cobalamin (B 12 ) Thiamin-pyrophosphate (TPP) FMN & FAD NAD & NADP Pyridoxal phosphate (PLP) Biotin Tetra-hydro-folate (FH4) Coenzyme A Methylcobalamin, 5'- deoxyadenosylcobalamin

42.  The active form of Vitamin C is ascorbic acid.  Humans do not have the enzyme systems required for the synthesis of vitamin C and must get it as an external supply.

43.  The most important function for vitamin C is the synthesis of collagen, the principal tissue protein found in teeth, bones, tendons, blood vessels.  Antioxidant.

44. It results in scurvy, a disease characterized by skin changes, bleeding gum, tooth loss, fragile blood capillaries and bone fracture, many of which can be attributed to deficient collagen synthesis.

46. VitaminDeficiency Manifestations C (L-Ascorbic acid) Scurvy B1 (Thiamin) Beriberi B3 (Niacin) Pellagra Folic acid Megaloblastic anemia B 12 (Cobalamin) Pernicious Anemia

47. Vitamin A Vitamin D Vitamin E Vitamin K

49. Vitamin A occurs in two forms in food Retinoids RetinolRetinal Retinoic acid Carotene s α - carotene β - carotene γ - carotene

50. RETINOL RETINAL RETINOIC ACID β -ionone ring  Retinoids: comprise retinol (alcohol), Retinal (aldehyde) (retinaldehyde), and retinoic acid (preformed vitamin A, found only in foods of animal origin).

51.  Carotenoids: - Found in plants - comprise carotenes and related compounds - known as provitamin A, as they can be cleaved to yield retinaldehyde and hence retinol and retinoic acid. - The α, β, and γ carotenes are the most important provitamin A carotenoids.

52.  Vision  Regulation of gene expression & tissue differentiation.  Antioxidant.

54. Rhodopsin cycle comprises two distinct events Bleaching of rhodopsin & generation of nerve impulse Regeneration of rhodopsin

55. Retinol (in the form of 11 cis-retinal) play very important role in vision. It combine with specific protein (opsin) to produce rhodopsin which permit vision in darkness. Rhodopsin dissociated in light to opsin and trans retinal which isomerizes to 11-cis retinal by the enzyme isomerase.

56.  Night blindness.  Xerophthalmia.  Impairment of immune responses.  Infections.  keratinization of skin.

59.  Vitamin D is not strictly a vitamin since it can be synthesized in the skin, and under most conditions that is its major source.  Only when sunlight is inadequate is a dietary source required.  Diet: Ergocalciferol (vitamin D2), found in plants, and cholecalciferol (vitamin D3), found in animal tissues, are sources of preformed vitamin D activity.  Endogenous vitamin precursor: (body can synthesize it but human should exposed to sun).

60.  7-Dehydrocholesterol (an intermediate in the synthesis of cholesterol that accumulates in the skin), on exposure to ultraviolet light converted to cholecalciferol (vitamin D3), which is absorbed into the bloodstream.  Vitamin D3 is metabolically inactive until it is hydroxylated in the kidney & the liver to the active form 1,25 Dihydroxycholecalciferol.  1,25 DHC acts as a hormone rather than a vitamin endocrine & paracrine properties.

61. Vitamin D Functions  The main function of vitamin D is in the regulation of calcium absorption.  Calcitriol is involved in insulin secretion, synthesis and secretion of parathyroid and thyroid hormones.

62. Vitamin D deficiency  Osteomalacia (in adults)  Rickets (in children)  Osteoporosis: bone loss disease

63.  Sunlight is the most important source  liver  Fatty Fish & sea food (herring & salmon)  Eggs yolk  Fortified milk.

65.  Vitamin E is the generic descriptor for two families of compounds, the tocopherols and the tocotrienols.  the most active is D-α-tocopherol.  The main function of vitamin E is as a chain-breaking, free radical trapping antioxidant in cell membranes and plasma lipoproteins.

66.  Hemolytic anemia

67. Sources

69.  Vitamin K forms: - In plants as phylloquinone (K1). -In intestinal bacterial flora as menaquinone (k2). -A synthetic form of vitamin K, menadione.  Vitamin K function: It is required for synthesis of blood clotting proteins

70. Fig. 8.11 phylloquinone

71.  Deficiency of vitamin K: A true vitamin K deficiency is unusual because adequate amounts are generally produced by intestinal bacteria or obtained from the diet.  Bleeding tendency.

72. Non-food source: bacteria in the large intestine

73. VitaminMain Functions A (Retinol) Night vision Healthy epithelium Growth and development of bone and teeth D (Cholecalceferol) Absorption of calcium and phosphorus Reabsorption of calcium from kidney Mineralization of bone and teeth E (Tocopherols) Anti-Oxidant K (Naphthoquinones) Blood clotting Synthesis of clotting factors

74. VitaminDeficiency Manifestations A (Retinol) Night blindness Xerophthalmia (= dryness of eye) Male sterility D (Cholecalceferol) Rickets in children Osteomalacia in adults  Serum Ca & P levels E (Tocopherols) Hemolytic anemia K Bleeding tendency

75. Many researchers have claimed that vitamin supplementation do not only provide no real health benefits, but could also be the source of increased mortality. In some cases, dietary supplementation could have unwanted effects, especially with other dietary supplements and medicines.

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