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WATER SOLUBLE VITAMINS
Vitamins B and C
• Functions
• Effects of deficiency
• Sources
• Properties
• RDA
M.A.Calvey/Vitamins 2006 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
* Nutrients required in very small amounts - mg or µg
MACalvey/Teachnet/Vitamins 2006 3
VITAMINS - Two main categories
Water soluble
B C
Fat Soluble
AD EK
MACalvey/Teachnet/Vitamins 2006 4
Water soluble
• Cannot be stored in body - regular supply needed
• Excess is excreted in urine - no 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
MACalvey/Teachnet/Vitamins 2006 5
Vitamin B1 - 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
MACalvey/Teachnet/Vitamins 2006 6
Vitamin B1 - Thiamine
SourcesMeat and offalOatmeal, breakfast
cerealsWheatgermFortified white flour MilkEggsVegetables
MACalvey/Teachnet/Vitamins 2006 7
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 8
Vitamin B2 -Riboflavin
Functions
• Metabolism of carbohydrates, proteins and fats
• Growth, repair, development of body tissues - healthy skin, eyes and tongue
• The principal growth promoting factor in the vitamin B complex
Deficiency• Loss of appetite• Swollen tongue,
cracked lips, eye infection, dermatitis
MACalvey/Teachnet/Vitamins 2006 9
Vitamin B2 -Riboflavin
SourcesOffalMilkCheeseEggsYeast extractsGreen Vegetables
MACalvey/Teachnet/Vitamins 2006 10
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 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
MACalvey/Teachnet/Vitamins 2006 12
Vitamin B -Niacin (Nicotinic acid)
SourcesMeat, OffalYeast extractsYeastBran, wheatgerm, flourSome pulses, dried fruit
MACalvey/Teachnet/Vitamins 2006 13
Properties• Water soluble• Stable to heat• Fairly stable to
acids/alkalis• 80 -90% loss in
milling
*RDA
15 - 20mg per day
Vitamin B -Niacin (Nicotinic acid)
*Related to protein intake
*Related to protein intake
MACalvey/Teachnet/Vitamins 2006 14
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 15
Vitamin B6 -Pyridoxine
SourcesMeatOffalEggsYeast extractsFishCereals
MACalvey/Teachnet/Vitamins 2006 16
Properties• Water soluble• Reasonably heat
stable• Sensitive to high
temperatures, oxygen, milling and processing
RDA
2mg per day
Vitamin B6 -Pyridoxine
MACalvey/Teachnet/Vitamins 2006 17
Vitamin B12 - (Cyano) Cobalamin
Functions
• Red blood cell formation
• Nervous system - maintains myelin sheath around nerves
• Helps treat pernicious anaemia
Deficiency• Pernicious anaemia• Nerve degeneration
MACalvey/Teachnet/Vitamins 2006 18
Vitamin B12 - (Cyano) Cobalamin
SourcesMeat, OffalFishCheese
No B12 in plant foods - Vegans, vegetarians risk of deficiency
No B12 in plant foods - Vegans, vegetarians risk of deficiency
MACalvey/Teachnet/Vitamins 2006 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 B12 - (Cyano) Cobalamin
MACalvey/Teachnet/Vitamins 2006 20
Vitamin B -Folic AcidFunctions
• 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
Important to take folic acid prior to conception and vital during first 3 months pregnancy
MACalvey/Teachnet/Vitamins 2006 21
Vitamin B -Folic Acid
SourcesOffalFortified cerealsGreen leafy vegetablesPotatoesbreadMilkWheatgerm
MACalvey/Teachnet/Vitamins 2006 22
Properties• Water soluble• Unaffected by acids• Sensitive to light and
oxidation
RDA
300 µg per day
More during pregnancy
Vitamin B -Folic Acid
MACalvey/Teachnet/Vitamins 2006 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
MACalvey/Teachnet/Vitamins 2006 24
Vitamin C -Ascorbic Acid
SourcesRosehips, blackcurrants, green peppers, kiwi,
citrusfruits, strawberries, spinach, cabbage, broccolli
MACalvey/Teachnet/Vitamins 2006 25
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
Vitamin C -Ascorbic Acid
Least stable of all vitamins
Least stable of all vitamins