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THE VITAMIN B COMPLEX

THE VITAMIN B COMPLEX. DEFINITION OF VITAMINS. An organic substance that occurs in foods in small amounts and is necessary for normal metabolic functioning of the body May be water soluble or fat soluble Do not contribute directly to the structure of the body, nor do they supply energy

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THE VITAMIN B COMPLEX

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  1. THE VITAMIN B COMPLEX

  2. DEFINITION OF VITAMINS • An organic substance that occurs in foods in small amounts and is necessary for normal metabolic functioning of the body • May be water soluble or fat soluble • Do not contribute directly to the structure of the body, nor do they supply energy • They regulate metabolism by releasing energy from fats and carbohydrates • They are involved in amino acid metabolism and also assist in forming blood, bones and tissues

  3. DIVISION OF VITAMIN B • Those vitamins that primarily release energy from carbohydrates and fats namely THIAMINE, NIACIN, RIBOFLAVIN, PANTOTHENIC ACID AND BIOTIN • Those that catalyze formation of red blood cells namely FOLIC ACID AND VITAMIN B12 • The vitamin that is important in protein and amino acid metabolism like VITAMIN B6

  4. VITAMIN B1- THIAMINE • VITAMIN B2- RIBOFLAVIN • VITAMIN B3- NIACIN • VITAMIN B5- PANTOTHENIC ACID • VITAMIN B6- PYRIDOXINE • FOLIC ACID • BIOTIN • VITAMIN B12- COBALAMIN

  5. THIAMINE (VIT. B1) • Water Soluble • Relatively unstable • Destroyed with heat • Destroyed in alkaline environment • Active form is thiamine pyrophosphate (TPP)

  6. Absorption and Metabolism • Easily absorbed from the small intestine. • It is combine with phosphate within mucosal cells of the intestine and transported via the portal vein into the general circulation. • Maybe found in liver, heart, brain and muscle tissue.

  7. Function • Important coenzyme in carbohydrate metabolism- pyruvate dehydrogenase, α ketoglutarate dehydrogenase and trans ketolase. • It acts as coenzyme in the production of ribose • Needed for the metabolism of carbohydrates, proteins and fats

  8. Food Sources • Cereals, meats, and legumes • The richest sources are brewer’s yeast, lean pork, liver, beef, dried peas and beans, nuts and whole wheat, parboiled rice enriched cereals and breads

  9. Deficiency • Occurs on consumption of diet that mainly consists of polished rice. • Also in children with malnutrition,persistent vomiting and adults with alcohol abuse. • Beri-Beri – affects principally the cardiovascular, muscular, and nervous system • Wet- mainly affecting CVS • Dry – mainly neurological symptoms • Infantile – features of both present • Wernicke- Korsakoff Syndrome- a combination of Wernicke’s encephalopathy and Korsakoff psychosis.

  10. Wet Beriberi • Signs of CCF present • Edema of the legs, cardiac disturbances such as enlarged heart, systolic murmurs and dyspnea may develop • The pulse is rapid and irregular, and the neck veins are distended

  11. Dry Beriberi • Edema does not occur • Associated with nervous system involvement- • Apathy, confusion, depression, drowsiness • Ataxia • Headache ,irritability, insomnia • Diminished or lost tendon reflexes • Paresthesia (prickling or burning) and numbness of the feet and cramps in the legs is present • Ophthalmoplegia • Polyneuritis and peripheral neuropathy

  12. Infantile Beriberi • Caused by inadequate thiamine in the breast milk, seen in infants of mothers with thiamine deficiency • Age of onset is 2-3 months • May present with features both wet and dry beriberi.

  13. Wernicke’s Syndrome • Severe deficiency of thiamine • Characterized by confusion, ataxia, paralysis of eye muscles(bilateral symmetrical ophthalmoplegia) and loss of memory • Peculiar gait and foot and wrist drop are seen in advanced cases • Can lead to coma and death

  14. RIBOFLAVIN (VIT. B2) • Water Soluble • Relatively stable • Functions as coenzyme-in oxidation of carbohydrates and aminoacids • Active as Flavin mononucleotide (FMN) • Or Flavin adenine dinucleotide (FAD)

  15. Absorption and Metabolism • It must be phosphorylated (combined with phosphate) in the intestinal tract before it can be absorbed • Excess riboflavin is excreted in the urine

  16. Function • Acts as hydrogen carriers • Assist in the metabolism carbohydrates, protein and fats • Oxidation of most drugs (called the drug vitamin)

  17. Sources • Milk, liver, heart, and kidney • Lean meat • Cheese • Eggs • Leafy green vegetables

  18. Deficiency • Gastrointestinal disease that causes vomiting and hypermotility of the gastrointestinal tract • Angular stomatis or cheilosis • Glossitis – sore, red, glazed and smooth tongue, atrophy of lingual papillae( MAGENTA TONGUE) • Dyssebacia- plugging of the sebaceous glands • Scrotal and vulval dermatitis • Eyes- vascularisation of cornea, cataract, keratitis, watering of eyes.

  19. NIACIN (VIT. B3) • Water Soluble • Very Stable • Active as Nicotinamide Adenine Dinucleotide (NAD) And NAD-phosphate (NADP) • A peculiar vitamin since it can be synthesized in body (via tryptophan)

  20. Absorption and Metabolism • Absorbed in the upper part of the small intestine • It is stored only sparingly in the kidney, heart, brain, and liver and is excreted in the urine

  21. Function • Forms the active portion of the coenzymes that play an essential role in supplying organ tissues, making its presence necessary for the health of cells • Acts as catalyst in accepting and releasing hydrogen in cellular respiration, carbohydrate metabolism and fat synthesis • It is needed for normal functioning of nervous system,skin and GIT

  22. Deficiency • Pellagra – characterized as the disease causing 4D’s • Dermatitis • Diarrhea • Depression • Death

  23. Sources • Found in appreciable amounts in liver, yeast, meat, legumes, peanuts and whole cereals • Foods that are good sources of tryptophan, such as animal protein and vegetable protein

  24. Symptoms • Muscle weaknessWeakness • Persistent fatiguability • Irritability • Headache • Depression, dementia • Soreness and inflammation of the tongue (glossitis- beefy red tongue, painful) and mouth (stomatitis) • Dermatitis- involving parts of body that are sun exposed. Casals necklace, pellagra glove and pellagra boot

  25. PANTOTHENIC ACID (VIT. B5) • Sometimes, erroneously called – Vitamin B5 • So plentiful in grains and vegetables, a deficiency unlikely – except in complete starvation

  26. Function • Involved in the release of energy from the catabolism of carbohydrates, proteins, and fats • It initiates the Krebs cycle and releases ATP • It is the starting substance for the biosynthesis of cholesterol and other sterols, a component of hemoglobin

  27. Sources • Widely distributed, occuring abundantly in yeast and in animal tissue such as liver and eggs, whole-grain cereals and legumes • Other fair sources are milk, fruits, and vegetables such as broccoli,cauliflower, and potatoes

  28. Deficiency • Fatigue • Sleep disturbances • Headaches • Malaise • Nausea • Acne • Burning, prickling sensations (paresthesia) of the hands and feet, cramping of the leg muscles and impaired coordination

  29. PYRIDOXINE (VIT. B6) • Water-soluble • White crystalline compound that is stable to heat and strong acids • 3 active forms: Pyridoxine Pyridoxamine Pyridoxal

  30. Function • Helps make red blood cells • Helps in amino acid and fatty bacid metabolism • Aids in normal functioning of nervous tissue

  31. Sources • Liver • Muscle meats • Yeast • Legumes • Whole grain cereals • Wheat germ • Wheat bran

  32. Deficiency • Early deficiency signs • Weakness • Irritability • Nervousness • Insomnia • Later deficiency signs • Convulsions, peripheral neuropathy • Anemia- microcytic hypochromic anemia refractory to iron therapy • Lesions around lips and eyes (red, crusty)

  33. Drugs predisposing to pyridoxine deficiency: • INH • Estrogens • Penicillamine • Cycloserine

  34. BIOTIN (VIT. H) • Unlikely to have deficiency • Is blocked by raw egg whites • Active biological substance

  35. Function • Stimulates the growth of yeast and bacteria • Functions as a coenzyme for reactions involving the addition of carbon dioxide in the formation of purines

  36. Sources • The richest sources are liver, kidney, milk, egg yolk and yeast , peanuts • Synthesised in the intestines by microorganisms

  37. Deficiency • Dermatitis • Glossitis • Loss of appetite and sleep, anemia • Nausea • Muscular pains • Hyperesthesia (increased skin sensitivity) • Paresthesia (burning and prickling sensation) • Alopecia

  38. FOLIC ACID (VIT. B9) • Yellow crystalline substance • Sparingly soluble in water

  39. Function • Essential for the manufacture and maturation of blood cells • Necessary for the normal functioning of the hematopoietic system • Prevent anemia, some birth defects and heart disease.

  40. Sources • Liver • Kidney • Yeast • Dark green leafy vegetables • Asparagus • Brocolli • Soybeans and nuts • Orange juice

  41. Deficiency • Disorders of malabsorption associated with infectious disease (tropical diseases) or certain metabolic and endocrine disorders • Megaloblastic anemia of pregnancy • Paresthesia • Angular cheilosis and gingivitis • Impaired immunity • Folic acid def. in mothers predisposes toneural tube defects in the babies

  42. CYANOCOBALAMIN (VIT. B12) • Consist of a cyanide ion and a cobalt ion • Not a single substance but consist of several closely related compounds having similar activity • By product of streptomycin

  43. Function • Plays a biomechanical role in the maintenance of myelin • Involved in the synthesis of nucleoproteins • It is essential for formation and maturation of red blood cells

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