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

* 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


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


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



SourcesMeat and offalOatmeal, breakfast

cerealsWheatgermFortified white flour MilkEggsVegetables



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


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



SourcesOffalMilkCheeseEggsYeast extractsGreen Vegetables



Properties• Water soluble• Unstable at high

temperatures• Destroyed by alkalis• Light sensitive

RDA

1 - 1.5 mg per day


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



SourcesMeat, OffalYeast extractsYeastBran, wheatgerm, flourSome pulses, dried fruit


Properties• Water soluble• Stable to heat• Fairly stable to

acids/alkalis• 80 -90% loss in

milling

*RDA

15 - 20mg per day


*Related to protein intake

*Related to protein intake


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



SourcesMeatOffalEggsYeast extractsFishCereals


Properties• Water soluble• Reasonably heat

stable• Sensitive to high

temperatures, oxygen, milling and processing

RDA

2mg per day



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



SourcesMeat, OffalFishCheese

No B12 in plant foods - Vegans, vegetarians risk of deficiency

No B12 in plant foods - Vegans, vegetarians risk of deficiency


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 -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


Vitamin B -Folic Acid

SourcesOffalFortified cerealsGreen leafy vegetablesPotatoesbreadMilkWheatgerm


Properties• Water soluble• Unaffected by acids• Sensitive to light and

oxidation

RDA

300 µg per day

More during pregnancy

Vitamin B -Folic Acid


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



SourcesRosehips, blackcurrants, green peppers, kiwi,

citrusfruits, strawberries, spinach, cabbage, broccolli


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

Least stable of all vitamins

Documents

WATER SOLUBLE VITAMINS Vitamins B and C Functions Effects of deficiency Sources Properties RDA