WATER SOLUBLE VITAMINS Vitamins B and C • Functions • Effects of deficiency • Sources • Properties • RDA VITAMINS • “VITAMIN” means “vital for life” * Nutrients required in very small amounts mg or µg • VITAMINS are *Micronutrients which are necessary for everyday healthy functioning of the body M.A.Calvey/Vitamins 2006 2 VITAMINS Two main categories Water soluble Fat Soluble B C A D E K MACalvey/Teachnet/Vitamins 2006 3 Water soluble • Cannot be stored in body - regular supply needed Fat Soluble • Can be stored in body regular supply not needed • Excess is excreted in • Can accumulate to toxic urine - no danger of toxic levels if large amounts levels ingested • Unstable to heat and light, leach into cooking liquids • Fairly stable at normal cooking temperatures MACalvey/Teachnet/Vitamins 2006 4 Vitamin B1 - Thiamine Functions • Essential for release of energy from carbohydrates • Necessary for appetite and good health Deficiency • Fatigue, depression, irritability • Beri-beri - disease of nervous system Common in countries where polished rice is staple food • Needed for normal functioning of nervous system MACalvey/Teachnet/Vitamins 2006 5 Vitamin B1 - Thiamine Sources Meat and offal Oatmeal, breakfast cereals Wheatgerm Fortified white flour Milk Eggs Vegetables MACalvey/Teachnet/Vitamins 2006 6 Vitamin B1 - Thiamine Properties • Water soluble • Destroyed by high temperatures • Destroyed by alkalis • Lost by milling flour, leaching into cooking liquids and in thawing frozen food RDA 1mg per day Requirement increases with energy expenditure MACalvey/Teachnet/Vitamins 2006 7 Vitamin B2 -Riboflavin Functions • Metabolism of carbohydrates, proteins and fats • Growth, repair, development of body tissues - healthy skin, eyes and tongue Deficiency • Loss of appetite • Swollen tongue, cracked lips, eye infection, dermatitis • The principal growth promoting factor in the vitamin B complex MACalvey/Teachnet/Vitamins 2006 8 Vitamin B2 -Riboflavin Sources Offal Milk Cheese Eggs Yeast extracts Green Vegetables MACalvey/Teachnet/Vitamins 2006 9 Vitamin B2 -Riboflavin Properties • Water soluble • Unstable at high temperatures • Destroyed by alkalis • Light sensitive RDA 1 - 1.5 mg per day MACalvey/Teachnet/Vitamins 2006 10 Vitamin B -Niacin (Nicotinic acid) Functions • Metabolism of carbohydrates, proteins and fats • Needed for normal functioning of nervous system Deficiency • Fatigue, depression, irritability • Beri-beri - disease of nervous system Common in countries where polished rice is staple food MACalvey/Teachnet/Vitamins 2006 11 Vitamin B -Niacin (Nicotinic acid) Sources Meat, Offal Yeast extracts Yeast Bran, wheatgerm, flour Some pulses, dried fruit MACalvey/Teachnet/Vitamins 2006 12 Vitamin B -Niacin (Nicotinic acid) Properties • Water soluble • Stable to heat • Fairly stable to acids/alkalis • 80 -90% loss in milling *RDA *Related to protein intake 15 - 20mg per day MACalvey/Teachnet/Vitamins 2006 13 Vitamin B6 -Pyridoxine Functions • Protein metabolism • Involved in formation of haemoglobin, hormones and structural proteins • Healthy development of nervous system Deficiency • Tiredness and Fatigue, irritability • Premenstrual tension • Infants may suffer convulsions if there is deficiency MACalvey/Teachnet/Vitamins 2006 14 Vitamin B6 -Pyridoxine Sources Meat Offal Eggs Yeast extracts Fish Cereals MACalvey/Teachnet/Vitamins 2006 15 Vitamin B6 -Pyridoxine Properties • Water soluble • Reasonably heat stable • Sensitive to high temperatures, oxygen, milling and processing RDA 2mg per day MACalvey/Teachnet/Vitamins 2006 16 Vitamin B12 - (Cyano) Cobalamin Functions • Red blood cell formation • Nervous system maintains myelin sheath around nerves Deficiency • Pernicious anaemia • Nerve degeneration • Helps treat pernicious anaemia MACalvey/Teachnet/Vitamins 2006 17 Vitamin B12 - (Cyano) Cobalamin Sources Meat, Offal Fish Cheese No B12 in plant foods - Vegans, vegetarians risk of deficiency MACalvey/Teachnet/Vitamins 2006 18 Vitamin B12 - (Cyano) Cobalamin Properties • Water soluble • Heat stable up to 100°C • Affected by strong acids/alkalis • Affected by light RDA 3-4 µg per day MACalvey/Teachnet/Vitamins 2006 19 Vitamin B -Folic Acid Functions • Red blood cell formation • Essential for synthesis of DNA and RNA • Development of brain, spinal cord and skeleton in foetus • Reduces risk of neural tube defects e.g. spina bifida • May play role preventing heart attacks, strokes and cancer Deficiency • Fatigue in mild cases • Anaemia in severe cases • Neural tube defects Important to take folic acid prior to conception and vital during first 3 months pregnancy MACalvey/Teachnet/Vitamins 2006 20 Vitamin B -Folic Acid Sources Offal Fortified cereals Green leafy vegetables Potatoes bread Milk Wheatgerm MACalvey/Teachnet/Vitamins 2006 21 Vitamin B -Folic Acid Properties • Water soluble • Unaffected by acids • Sensitive to light and oxidation RDA 300 µg per day More during pregnancy MACalvey/Teachnet/Vitamins 2006 22 Vitamin C -Ascorbic Acid Functions • Formation of connective tissue, collagen • Critical to immune system • Helps absorption of iron • Prevents scurvy • Promotes healing of wounds and healthy blood vessels • Acts as antioxidant, protects HDL cholesterol Deficiency • Weakening of connective tissue • Susceptibility to infection • Incomplete iron absorption • Delayed healing of wounds MACalvey/Teachnet/Vitamins 2006 23 Vitamin C -Ascorbic Acid Sources Rosehips, blackcurrants, green peppers, kiwi, citrus fruits, strawberries, spinach, cabbage, broccolli MACalvey/Teachnet/Vitamins 2006 24 Vitamin C -Ascorbic Acid Properties • Water soluble • Destroyed by alkalis, dry or moist heat and enzymes • Sensitive to light and oxygen RDA 30-60 mg per day • Acts as an antioxidant Least stable of all vitamins MACalvey/Teachnet/Vitamins 2006 25 MACalvey/Teachnet/Vitamins 2006 26