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
- regular supply needed
• Can be stored in body 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 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
5
Vitamin B1 - Thiamine
Sources
Meat and offal
Oatmeal, breakfast
cereals
Wheatgerm
Fortified white flour
Milk
Eggs
Vegetables
6
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
7
Vitamin B2 -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 B2 -Riboflavin
Sources
Offal
Milk
Cheese
Eggs
Yeast extracts
Green Vegetables
9
Vitamin B2 -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 - 20mg per day
13
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
14
Vitamin B6 -Pyridoxine
Sources
Meat
Offal
Eggs
Yeast extracts
Fish
Cereals
15
Vitamin B6 -Pyridoxine
Properties
• Water soluble
• Reasonably heat stable
• Sensitive to high
temperatures, oxygen,
milling and processing
RDA
2mg per day
16
Vitamin B12 - (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 B12 - (Cyano) Cobalamin
Sources
Meat, Offal
Fish
Cheese
No B12 in plant
foods - Vegans,
vegetarians risk
of deficiency
18
Vitamin B12 - (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