WATER SOLUBLE VITAMINS Vitamins B and C Functions

WATER SOLUBLE VITAMINS Vitamins B and C • Functions • Effects of deficiency • Sources • Properties • RDA © PDST Home Economics

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 2

VITAMINS Two main categories Water soluble Fat Soluble B C A D E K 3

Water soluble Fat Soluble • Cannot be stored in body - • Can be stored in body regular supply needed regular supply not needed • Excess is excreted in urine - little danger of toxic levels • Can accumulate to toxic levels if large amounts ingested • Unstable to heat and light, leach into cooking liquids • Fairly stable at normal cooking temperatures 4

Vitamin B 1 - Thiamine Functions • Essential for release of energy from carbohydrates • Necessary for appetite and good health • 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 5

Vitamin B 1 - Thiamine Sources Meat and offal Oatmeal, breakfast cereals Wheatgerm Fortified white flour Milk Eggs Vegetables 6

Vitamin B 1 - 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 1 mg per day Requirement increases with energy expenditure 7

Vitamin B 2 -Riboflavin Functions • Metabolism of carbohydrates, proteins and fats • Growth, repair, development of body tissues - healthy skin, eyes and tongue • The principle growth promoting factor in the vitamin B complex Deficiency • Loss of appetite • Swollen tongue, cracked lips, eye infection, dermatitis 8

Vitamin B 2 -Riboflavin Sources Offal Milk Cheese Eggs Yeast extracts Green Vegetables 9

Vitamin B 2 -Riboflavin Properties • Water soluble • Unstable at high temperatures • Destroyed by alkalis • Light sensitive RDA 1 - 1. 5 mg per day 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 11

Vitamin B -Niacin (Nicotinic acid) Sources Meat, Offal Yeast extracts Yeast Bran, wheatgerm, flour Some pulses, dried fruit 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 - 20 mg per day 13

Vitamin B 6 -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 14

Vitamin B 6 -Pyridoxine Sources Meat Offal Eggs Yeast extracts Fish Cereals 15

Vitamin B 6 -Pyridoxine Properties • Water soluble • Reasonably heat stable • Sensitive to high temperatures, oxygen, milling and processing RDA 2 mg per day 16

Vitamin B 12 - (Cyano) Cobalamin Functions • Red blood cell formation • Nervous system - maintains myelin sheath around nerves Deficiency • Pernicious anaemia • Nerve degeneration • Helps treat pernicious anaemia 17

Vitamin B 12 - (Cyano) Cobalamin Sources Meat, Offal Fish Cheese No B 12 in plant foods - Vegans, vegetarians risk of deficiency 18

Vitamin B 12 - (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 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 20

Vitamin B -Folic Acid Sources Offal Fortified cereals Green leafy vegetables Potatoes bread Milk Wheatgerm 21

Vitamin B -Folic Acid Properties • Water soluble • Unaffected by acids • Sensitive to light and oxidation RDA 300 µg per day More during pregnancy 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 23

Vitamin C -Ascorbic Acid Sources Rosehips, blackcurrants, green peppers, kiwi, citrus fruits, strawberries, spinach, cabbage, broccoli 24

Vitamin C -Ascorbic Acid Properties • Water soluble • Destroyed by alkalis, dry or moist heat and enzymes • Sensitive to light and oxygen • Acts as an antioxidant RDA 30 -60 mg per day Least stable of all vitamins 25