Download MICRONUTRIENTS - vitamins

Water soluble Vitamins A, B, C, D
To know and understand:
• the functions
• main sources
• effects of deficiency and excess
• related dietary reference values
• Theory Lesson
• Exam Practice
• Kahoot
• To give you knowledge of Micro nutrients and
their function in food products
Challenge: Able to identify sources of micronutrients and functions in body
Aspire: Can identify deficiency of micronutrients
Expert: Can remember all micronutrients and suggest ways of incorporating them into
daily diet
MICRONUTRIENTS
VITAMINS
A
B
C
D
E
VITAMINS
FAT SOLUBLE





Found in fat or oily parts
of foods
Require fat for absorption
Stored in the body
VITAMIN A
VITAMIN D
WATER SOLUBLE



Readily lost during food
preparation
Limited storage capacity
Excess excreted in the urine
B VITAMINS
 VITAMIN C

VITAMIN A
FORMS:
1.
Retinoids (retinol, retinal, retinoic acid)
2.Carotenoids (beta-carotene)
VITAMIN A: SOURCES
1.
RETINOIDS:
Animal foods –
eggs, butter, milk & milk products,
liver, fish, fish oils
Also: added to margarine.
VITAMIN A: SOURCES
2.
CAROTENOIDS:
Plant foods –
carrots, dark green leafy vegetables,
broccoli, red peppers, tomatoes,
apricots, peaches, mango
(Converted to retinol for absorption)
VITAMIN A: FUNCTIONS
Stored in the liver
 ‘A’ is for eyesight, especially night
vision
 Growth – regulates normal bone
growth
 Maintains integrity & function of
epithelial cells
(Epithelial cells are cells that line the inner and outer
surfaces of the body in continuous sheets)
 Anti-infective,
Antioxidant, supports
immune system
VITAMIN A: DEFICIENCIES
One of the top 3 world-wide major
public health problems
 Sight
problems e.g. ‘Night blindness’,
Dry eye, childhood blindness
 Poor functioning of lungs & digestive
tract
 Increased risk of infections
 Rough, dry skin; Acne
VITAMIN A: TOXIC EFFECTS
 Very
high amounts can cause
poisoning.
 High
 High
risk – Polar bears liver!
doses associated with birth
defects
VITAMIN D: SOURCES
Can be synthesized in the skin from a
pro-vitamin and sunlight.
Pro-vitamins found in:
1. Animal fats
2. Yeast & fungi (source of commercial
vitamin production)
In UK, no synthesis between October &
March.
VITAMIN D: SOURCES
Dietary sources :
 Eggs
 Milk & butter
 Meat, oily fish (fish oil supplements),
liver
 Margarines (fortified – legal
requirement)

Also added to breakfast cereals, yogurts,
baby foods, bedtime drinks, evaporated
milk
VITAMIN D: FUNCTIONS
 Aids
absorption and utilisation of
Calcium
 Aids kidney function
 Supports immune system
VITAMIN D: DEFICIENCIES
Bone & growth problems:
 Rickets
(in growing children; soft
bones become deformed)
 Osteomalacia (in adults; as above)
Causes muscular weakness & bone
pain
VITAMIN D: TOXIC EFFECTS
Unusual, most likely to be caused by
over-consumption of vitamin
supplements
B-complex VITAMINS
B
B
B
B
B
B

1
2
3
6
12
9
– Thiamine
– Riboflavin
– Niacin
– Pyridoxine
– Cobalamin
- Folate
Share functions, often
work together
Cofactors in
metabolism
Involved in production
& use of energy
Folate & B12 involved in
cell division
B-COMPLEX: Thiamine B
Sources;
Cereals, especially wholegrains
1

(breakfasts & white flour are
fortified)
Beans, seeds, nuts
(Also found in pork, liver, milk & milk products)
Role:
Metabolism of CHO & protein,
alcohol & drugs, Supports nerve
function

Deficiencies:
Beriberi (in undernourished Asian populations)
Neurological problems (associated with alcoholism)

B-COMPLEX: RIBOFLAVIN B
2
Sources:
Milk, eggs, yeast, meat (especially liver), tea,
fortified breakfasts, dark green leafy vegetables
 Role:
Many functions including – macro & micronutrient
metabolism, energy release, nutrient
interrelationships.
 Deficiencies:
Mouth – dry, cracked lips, tongue changes
Eyes – itching, burning, light sensitive, sticky
Skin – oily dermatitis
Linked to anaemia

B-COMPLEX: Niacin B
3
Sources:
Meat (especially liver), cereals, milk & dairy
products, vegetables, coffee, cocoa.
 Role:
Metabolism of CHO, fats, proteins; Vitamin
C, folate, alcohol. Also role in insulin
function
 Deficiencies:
Pellagra - affects skin, intestines, brain

B-COMPLEX: B
6
Sources:
Liver, wholegrains, red meat & poultry,
peanuts, walnuts, bananas, salmon. Some
in broccoli, spinach, potatoes. Beer.
 Role:
Metabolism of Protein, fat & CHO. Energy
release, hormone regulation
 Deficiencies:
Not specific; linked to anaemia, mouth
problems, nerve/muscle problems

B-COMPLEX - SUMMARY:
 Widely
distributed in animal & plant
foods
 Essential for metabolic and cellular
functions
 Increased needs with high intakes of
alcohol, drugs, trauma (eg surgery),
cancer, kidney or liver disease
 Not much stored in body – regular
intakes required.
B-COMPLEX: FOLATE B9
Sources:
Green leafy vegetables (spinach, Brussels sprouts).
Also in: liver, broccoli, cabbage, cauliflower,
parsnips, fortified cereals & bread &whole wheat.
Milk & fruit, (especially oranges). Beer (due to
yeast)
 Role:
Crucial for cell division – prevention of neural tube
defects in developing foetus
 Deficiencies:
Anaemia, birth defects (Spina Bifida, brain damage)
Associated with depression, dementia, cardiovascular disease

VITAMIN B
12
Stored in the body (liver)
 SOURCES:
Found only in animal foods – Liver. Meat, fish,
eggs, milk and dairy products. Added to Marmite.
(Affected by excess amounts of Vitamin C)
 Role:
Metabolism of some fatty acids & folates
 Deficiencies:
Anaemia, damage to nerves leading to loss of
sensory & motor function
Relies on ‘intrinsic factor’ from the stomach for
absorption
GOOD ‘B’ SOURCE:
1 teaspoon per day…
VITAMIN C: FACTOIDS
 Also
known as Ascorbic Acid
 Most
animals can synthesize it from
glucose (not humans, guinea-pigs)
 Least
stable of all vitamins
SOURCES
VITAMIN C: SOURCES
 Fruit
and vegetables
VITAMIN C: FUNCTION:
Enhances iron absorption
 Collagen synthesis
 Supports hormone function
 Release of energy from fatty acids
 Antioxidant
 Supports immune system, and liver
detoxification
 Can relieve cold symptoms (but not
prevent them)

VITAMIN C: DEFICIENCIES
 Scurvy
 Low
intakes associated with cancers,
heart disease, cataracts, poor wound
healing
 Smokers
have poor Vit. C status
Scurvy
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Micronutrients - Vitamins