Chap7 the b complex vitamins


Published on

  • Be the first to comment

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Chap7 the b complex vitamins

  1. 1. The B Complex Vitamins
  2. 2. Vitamin Defined • 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. 3. Division of Vitamin B • Those vitamins that primarily release energy from carbohydrates and fats namely thiamin, 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 • The vitaminlike compounds
  4. 4. Thiamine (Vit. B1) • A member of the B-complex family • Water Soluble • Relatively unstable – Destroyed with heat – Destroyed in alkaline environment – Active as thiamine pyrophosphate (TPP) – Or as thiamine tri-phosphate (TT
  5. 5. 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
  6. 6. Function • Important coenzyme in energy metabolism • It acts as coenzyme in the production of ribose • Needed for the metabolism of carbohydrates, proteins and fats
  7. 7. Deficiency • Beri-Beri – affects principally the cardiovascular, muscular, and nervous system – Wet – Dry – Infantile • Wernicke’s Syndrome • Increased sensitivity of the oral mucosa, burning tongue, and loss or diminution of taste
  8. 8. Wet Beriberi • Edema (accumulation of fluid in tissues spaces) of the legs, cardiac disturbances such as enlarged heart, systolic murmurs and dyspnea (difficulty of breathing) may develop • The pulse is rapid and irregular, and the neck veins are distented
  9. 9. Dry Beriberi • Edema does not occur • A condition consisting of paresthesia (prickling or burning) and numbness of the feet and cramps in the legs is present
  10. 10. Infantile Beriberi • Caused by inadequate thiamin in the breast milk • Characterized by dyspnea, cyanosis and cardiac failure
  11. 11. Wernicke’s Syndrome • Severe deficiency of thiamin in the alcoholic individual • Characterized by confusion, paralysis of eye muscles, and loss of memory • Peculiar gait and foot and wrist drop are seen in advanced cases
  12. 12. 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 and enriched cereals and breads
  13. 13. Riboflavin (Vit. B2) • One of the B-complex vitamins • Water Soluble • Relatively stable • Functions as coenzyme • Active as flavin mononucleotide (FMN) • Or flavin adenine dinucleotide (FAD)
  14. 14. 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
  15. 15. Function • Acts as hydrogen carriers • Assist in the metabolism carbohydrates, protein and fats • Oxidation of most drugs (called the drug vitamin)
  16. 16. Deficiency • Gastrointestinal disease that causes vomiting and hypermotility of the gastrointestinal tract • Angular stomatis • Glossitis
  17. 17. Sources • Milk, liver, heart, and kidney • Lean meat • Cheese • Eggs • Leafy green vegetables
  18. 18. Niacin (Vit. B3) • One of the B-complex nutrients • 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 tryptophane)
  19. 19. 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 exreted in the urine
  20. 20. 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
  21. 21. Deficiency • Pellagra – characterized as the disease causing 4D’s – Dermatitis – Diarrhea – Depression – Death
  22. 22. Symptoms • Weakness • Persistent fatigability • Irritability • Headache • Depression • Soreness and inflammation of the tongue (glossitis) and mouth (stomatitis)
  23. 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. 24. Pantothenic Acid (Vit. B5) • Sometimes, erroneously called – Vitamin B5 • So plentiful in grains and vegetables, a deficiency unlikely – except in complete starvation
  25. 25. 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
  26. 26. Deficiency • Fatigue • Sleep disturbances • Headaches • Malaise • Nausea • Abdominal stress • Burning, prickling sensations (paresthesia) of the hands and feet, cramping of the leg muscles and impaired coordination
  27. 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 brocolli,cauliflower, and potatoes
  28. 28. Pyridoxine (Vit. B6) • Water-soluble • White crystalline compound that is stable to heat and strong acids
  29. 29. Function • Helps make red blood cells • Helps in amino acid and fatty bacid metabolism • Aids in normal functioning of nervous tissue
  30. 30. Deficiency • Early deficiency signs – Weakness – Irritability – Nervousness – Insomnia • Later deficiency signs – Convulsions – Anemia – Lesions around lips and eyes (red, crusty)
  31. 31. Sources • Liver • Muscle meats • Yeast • Legumes • Whole grain cereals • Wheat germ • Wheat bran
  32. 32. Biotin (Vit. B7) • Very uneventful. • Unlikely to have deficiency • Is blocked by raw egg whites • Active biological substance
  33. 33. 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
  34. 34. Deficiency • Dermatitis • Glossitis • Loss of appetite and sleep • Nausea • Muscular pains • Hyperesthesia (increased skin sensitivity • Paresthesia (burning and prickling sensation) • Alopecia
  35. 35. Sources • The richest sources are liver, kidney, milk, egg yolk and yeast
  36. 36. Folic Acid (Vit. B9) • Yellow crystalline substance • Sparingly soluble in water
  37. 37. 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
  38. 38. 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
  39. 39. Sources • Liver • Kidney • Yeast • Dark green leafy vegetables • Asparagus • Brocolli • Soybeans and nuts • Orange juice
  40. 40. 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
  41. 41. Function • Plays a biomechanical role in the maintenance of myelin • Involved in the synthesis of nucleoproteins
  42. 42. Deficiency • Pernicious anemia – Usual complaints are weakness, numbness and tingling in the extremities – Patients may have difficulty in walking and coordination of movements – Vibratory sense may be absent – Patient may have a lemon-yellow complexion as a result of jaundice caused by red cell destruction, early graying of hair, fast heartbeat, ankle swelling and peripheral neuritis
  43. 43. Sources • Occurs primarily in animal foods, and liver is the richest source • Meat • Eggs • Milk • Cheese • Fish