Water Soluble Vitamins - Chapter 6 PDF

The water-soluble vitamins: B vitamins and vitamin C Prepared by: Dr. Hadeel Alsufiani Chapter outline: The vitamins- an overview the main roles, deficiency symptoms, recommendations and food sources for each of the B vitamins the main roles, deficiency symptoms, recommendations...

The water-soluble vitamins: B vitamins and vitamin C Prepared by: Dr. Hadeel Alsufiani Chapter outline: The vitamins- an overview the main roles, deficiency symptoms, recommendations and food sources for each of the B vitamins the main roles, deficiency symptoms, recommendations and food sources for vitamin C. THE VITAMINS- AN OVERVIEW Vitamins are organic, essential nutrients required in small amounts by the body to prevent deficiency diseases and to support optimal health. (vita= life, amine= containing nitrogen (the first vitamins discovered contained nitrogen)).  The vitamins differ from carbohydrates, fats and proteins in the following ways: Vitamins are individual units structure They are not linked together (as are molecules of glucose or amino acids). Vitamins don’t yield energy when metabolized function Many of them do, however, assist the enzymes that participate in the release of energy from carbohydrates, fats and proteins. The amounts of vitamins people Food ingest from foods and the amounts they require daily are measured in contents micrograms or milligrams, rather than grams. The vitamins ae similar to the energy yielding nutrients, though, in that they are essential, organic, and available from foods.  B vitamins Water soluble Vitamin C vitamins Vitamin A Vitamin D Fat soluble Vitamin E Vitamin K  The body handles the vitamins differently depending on whether they are water or fat soluble.  The B vitamins thiamin choline riboflavin vitamin niacin B12 The B vitamins folate biotin vitamin Pantothenic B6 acid  Several of the b vitamins- thiamine, riboflavin, niacin, pantothenic acid, and biotin- form part of the coenzymes that assist enzymes in the release of energy from carbohydrates, fat and protein. Thiamin (vitamin B1) Thiamin pyrophosphate (TPP) is the biologically active form of the vitamin, formed by the transfer of a pyrophosphate group from ATP to thiamin.  Role of thiamin TPP assists in energy in the metabolism body Thiamin occupies a special site on the membrane of nerve cells.  Thiamin's food sources: Thiamin recommend Whole-grain, ations Men: 1.2 mg/d fortified, or enriched grain products; moderate amounts Women: 1.1 mg/d in all nutritious food  Thiamin deficiency and toxicity: Dry Wet beriberi beriberi people who derive most of their energy from empty-calorie foods Reflects damage to and beverages risk thiamin Reflects damage to the nervous system the cardiovascular system deficiency. Characterized by dilated Prolonged thiamin deficiency can Characterized by muscle weakness in blood vessels, which cause the heart to work harder and the kidney to retain result in the disease beriberi. the arms and legs salt and water, resulting in edema. Beriberi is always described as No adverse effects have been ”dry” or “wet”. associated with excess of thiamin. Riboflavin (Vitamin B2) The two biologically active forms of B2 are flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD).  Role of riboflavin Riboflavin serves as a in the coenzyme in many body reactions, most notably in energy metabolism.  Deficiency Toxicity Riboflavin in foods symptoms symptoms Lack of the None reported vitamin causes inflammation of the membranes of the mouth, skin, eyes and GI tract. All of these foods are rich in riboflavin, but milk and milk products Riboflavin Recommendations provide much of the riboflavin in the diets of most people men: 1.3 mg/d RDA women: 1.1 mg/d Niacin (nicotinic acid) (Vitamin B3) The biologically active coenzymes forms are nicotinamide adenine dinucleotide (NAD+) and nicotinamide adenine dinucleotide phosphate (NADP+).  Role of niacin in NAD and NADP the body are central in energy-transfer reactions, especially the metabolism of glucose and fat. NAD also protects against neurological degeneration Niacin in foods Approximately 60mg of tryptophan is needed to make 1 mg of niacin. For this reason, recommended intakes are stated in niacin equivalents (NE) Milk, eggs, meat, Niacin Recommendations poultry, fish; whole- grains, fortified and men: 16 mg NE/d enriched grain RDA products; nuts. women: 14 mg NE/d Adults: 35 mg/d UL Food tryptophan sources Niacin equivalent (NE) : the amount of niacin present in food, including the niacin niacin that can theoretically be made in the from its precursor, tryptophan, present in body food. Niacin deficiency and toxicity: Deficiency Deficiency Toxicity disease symptoms symptoms pellagra diarrhea, Large doses dermatitis, of nicotinic dementia acid from and supplements eventually produces death (often “niacin called “ the flush”. 4Ds”) Biotin Role of biotin in Biotin plays an important the body role in metabolism as a coenzyme that carries activated carbon dioxide Biotin coenzyme also participates in gluconeogenesis, fatty acid synthesis, and the breakdown of certain fatty acids and amino acids Biotin Role of biotin in Biotin plays an the body important role in metabolism as a coenzyme that carries activated carbon dioxide Biotin coenzyme also participates in gluconeogenesis, fatty acid synthesis, and the breakdown of certain fatty acids and amino acids Biotin in foods Deficiency Toxicity symptoms symptoms rarely None occur reported biotin is widespread in foods (including egg yolks, liver, fish, whole grains) Biotin Recommendations adults: 30 µg/d AI Pantothenic acid (Vitamin B5) Pantothenic acid is part of coenzyme A- the same CoA that forms acetyl CoA, a key compound in several metabolic pathways, including the TCA cycle.  Role of pantothenic Involved in the acid in the formation of acetyl body CoA. Involved in the synthesis of lipids, neurotransmitters, steroid hormones and hemoglobin. Pantothenic acid in foods Deficiency Toxicity symptoms symptoms rarely None occur reported widespread in foods. Beef, poultry, whole grains, potatoes, tomatoes and broccoli are particularly good sources. Pantothenic acid Recommendations adults: 5 mg/d AI  Vitamin B6 Vitamin B6 occurs in three forms- pyridoxal, pyridoxine, and pyridoxamine. All three can be converted to the coenzyme PLP (pyridoxal phosphate).  Role of Vitamin PLP is active in more B6 in the than 100 reactions, including carbohydrates body and amino acid metabolism. PLP IS Involved in the conversion of tryptophan to niacin or to the neurotransmitter serotonin. PLP is participate in the synthesis of heme, nucleic acid and lecithin.  Role of Vitamin PLP is active in more B6 in the than 100 reactions, including carbohydrates body and amino acid metabolism. tryptophan niacin PLP IS Involved in the conversion of tryptophan to niacin or to the neurotransmitter serotonin. PLP is participate in the synthesis of heme, nucleic acid and lecithin. Vitamin B6 in foods Deficiency Toxicity symptoms symptoms depression neurological and damage confusion Meats, fish, poultry, potatoes, legumes, fortified cereals and liver Vitamin B6 Recommendations Adults: 1.3 mg/d RDA Adults: 100 mg/d UL Folate (Folacin) (Folic acid) Folic acid forms tetrahydrofolate (THF) (the reduced coenzyme of folate). THF receives one-carbon fragments from donors and transfers them to intermediates in the synthesis of amino acids.  Role of folate in the body Conversion of vitamin B12 to its coenzyme form. Synthesizes the DNA required for all rapidly growing cells Regenerates the amino acid methionine from homocysteine.  Folate and neural tube defects: Neural tube defects: the brain and spinal cord develop from the neural tube, and defects in its orderly formation during the early weeks of pregnancy may result in various central nervous system disorders and death. Folate supplements can help prevent neural tube defects. Folate in foods Deficiency Toxicity symptoms symptoms macrocytic or mask vitamin megaloblastic B12- deficiency anemia. symptoms Fortified grains, leafy green vegetables, legumes, seeds, liver Folate Recommendations Adults: 400 µg/d RDA Adults: 1000 µg/d UL Vitamin B12 (cobalamin) The physiologic coenzyme forms of cobalamin are 5’deoxyadenosylcobalamin and methylcobalamine, in which cyanide is replaced with 5’deoxyadenosine or a methyl group, respectively.  The digestion and absorption of vitamin B12 depends on several steps.  Vitamin B12 and folate are closely related : each depend on the other for activation  Role of vitamin The regeneration of the B12 in amino acid methionine and the synthesis of DNA the body and RNA depend on both folate and vitamin B12. Vitamin B12 maintains the sheath that surrounds and protects nerve fibers and promotes their normal growth Bone cell activity and metabolism also depend on vitamin B12 Vitamin B12 in foods Deficiency Toxicity Disease symptoms Perniciou None- s anemia reported Vitamin B12 is unique among the vitamins in being found almost exclusively in foods derived from animals. Pernicious anemia: a blood disorder that reflects a vitamin B12 deficiency caused by atrophic gastritis and a lack of intrinsic factor and Vitamin B12 Recommendations characterized by abnormally large and immature red blood cells. Adults: 2.4 µg/d RDA choline Although not defined as vitamins, choline is an essential nutrient that is commonly grouped with the B vitamins. Role of choline Needed for the synthesis of the neurotransmitter acetylcholine and the phospholipid lecithin.  Deficiency Toxicity symptoms symptoms Choline in foods liver Low blood damage pressure, reduced growth rate Milk, liver, eggs and peanuts Choline Recommendations men: 550 mg/d AI Women: 425 mg/d Adults: 3500 mg/d UL Vitamin C (ascorbic acid) The active form of vitamin c is ascorbic acid. The main function of ascorbate is as reducing agent in several different reactions. Vitamin C roles: Act As cofactor Act As an Thyroxine in collagen antioxidant synthesis formation Strengthens Helps in resistance to absorption of infection iron  Deficiency Toxicity Vitamin C in foods disease symptoms scurvy diarrhea and GI distress Citrus fruits, dark Vitamin C Recommendations green vegetables, strawberries, men: 90 mg/d tomatoes, mangoes RDA Women: 75 mg/d Smokers: +35 mg/d Adults: 2000 mg/d UL Activity Choose one card Main word Assistant word Assistant word Assistant word Assistant word Try to help your colleagues to guess the main word The student who answer in the top of the card by the first will be the winner using the 4 assistant words