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WATER SOLUBLE VITAMINS Vitamins B and C • Functions • Effects of deficiency • Sources • Properties • RDA
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
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 - ThiamineFunctions• 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 - ThiamineSourcesMeat and offalOatmeal, breakfast
cerealsWheatgermFortified white flour MilkEggsVegetables
MACalvey/Teachnet/Vitamins 2006 7
Vitamin B1 - ThiamineProperties• Water soluble• Destroyed by high
temperatures• Destroyed by alkalis• Lost by milling flour,
leaching into cooking liquids and in thawing frozen food
RDA1mg per day - Requirement increases with energy expenditure
MACalvey/Teachnet/Vitamins 2006 8
Vitamin B2 -RiboflavinFunctions• 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
RDA1 - 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
*RDA15 - 20mg per day
Vitamin B -Niacin (Nicotinic acid)
*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
RDA2mg 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
MACalvey/Teachnet/Vitamins 2006 19
Properties• Water soluble• Heat stable up to
100°C• Affected by strong
acids/alkalis• Affected by light
RDA3-4 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
MACalvey/Teachnet/Vitamins 2006 21
Vitamin B -Folic AcidSourcesOffalFortified cerealsGreen leafy vegetablesPotatoesbreadMilkWheatgerm
MACalvey/Teachnet/Vitamins 2006 22
Properties• Water soluble• Unaffected by acids• Sensitive to light and
oxidation
RDA300 µg per day More during pregnancy
Vitamin B -Folic Acid
MACalvey/Teachnet/Vitamins 2006 23
Vitamin C -Ascorbic AcidFunctions• 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
RDA30-60 mg per day
Vitamin C -Ascorbic Acid
Least stable of all vitamins
MACalvey/Teachnet/Vitamins 2006 26
