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

2 VITAMINS “VITAMIN” means “vital for life” VITAMINS are *Micronutrients which are necessary for everyday healthy functioning of the body * Nutrients required in very small amounts - mg or µg

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

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

5 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

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

7 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 1mg per day - Requirement increases with energy expenditure

8 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

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

10 Vitamin B 2 -Riboflavin Properties Water soluble Unstable at high temperatures Destroyed by alkalis Light sensitive RDA mg per day

11 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

12 Vitamin B -Niacin (Nicotinic acid) Sources Meat, Offal Yeast extracts Yeast Bran, wheatgerm, flour Some pulses, dried fruit

13 Properties Water soluble Stable to heat Fairly stable to acids/alkalis % loss in milling *RDA mg per day Vitamin B -Niacin (Nicotinic acid) *Related to protein intake

14 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

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

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

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

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

19 Properties Water soluble Heat stable up to 100°C Affected by strong acids/alkalis Affected by light RDA 3-4 µg per day Vitamin B 12 - (Cyano) Cobalamin

20 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

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

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

23 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

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

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