Transcript Nutrition and health

Al Neelain University
Faculty of Medicine
Sem.(7)
Primary Health Care Course-Nutrition
Nutrition and Health
Dr.Abeer Abuzeid Atta Elmannan Ali
Course contents:
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Dietary constituents.
Balanced diet.
Assessment of nutritional status.
Nutritional surveillance.
Nutritional indicators.
Common nutritional problems.
Foodborne diseases.
Session Outlines
Section I: Introduction to Nutrition
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What is Nutrition?
Dietary Constituents
Classification of foods.
What is a balanced Diet?
Principles of Balanced Diet.
Section II: Vitamin A Deficiency
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Sources of Vit.A, & Requirements
Deficiency.
Treatment.
Prevention & Control.
Definitions:
Nutrition:
The science of food and its relationship to health.
Good nutrition:
Maintaining a nutritional status that enables us to grow well
and enjoy good health
Dietetics:
Practical application of the principles of nutrition
Dietary constituents
Nutrients
Macronutrients:
Proteins ,fats and carbohydrates.
Micronutrients:
Vitamins and minerals.
Classification of foods
Classification by origin:
1- foods of animal origin.
2- Foods of vegetable origin.
Classification by chemical composition:
1-proteins
2-carbohydrates
3- fats
4- minerals
5- vitamins.
Classification of foods
Classification by predominant function:
1- body-building foods.
2- Energy-giving foods.
3- Protective foods.
Classification by nutritive value:
1- cereals
2- vegetables
3- fruits…….ect
Balanced diet:
Diet which contains a variety of foods in such quantities and
proportions that the need for all nutrients is adequately met
for maintaining health, and general wellbeing and also makes
small provision for extra nutrients to withstand short
duration of leanness.
Principles of constructing balanced diet:
• Daily requirement of protein should be met.(15-20% of daily
energy intake).
• Fat s limited to 20-30%
• Carbohydrates rich in natural fiber should constitute the
remaining food energy.
• Requirements for micronutrients should be met.
WHO Dietary goals:
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Fat should be limited to about 20-30%.
Saturated fats should be not more than 10%.
High consumption of refined CHO should be avoided.
Restrict sources rich in energy.
Salt intake should be reduced.
Proteins should account for 1—20%
Junk foods should be reduced.
Vitamin A deficiency
Vitamin A
Vit. A covers both
- pre-formed vitamin, retinol
- pro-vitamin ,beta carotene.
Functions:
- Vision
- Epithelial integrity
- Immune response
- Growth
- Fertility
Sources of Vit.A
• Animal foods.
• Plant foods.
• Fortified foods
Sources
•Retinol is fat-soluble
• naturally present in foods from animal sources only, for
example in dairy products and liver.
Sources:
• In plants, only precursors are found, i.e. the so-called provitamin A substances, such as carotene .
• They are particularly common in green leafy
Vit.A Storage & Transport
• Stored in the liver mostly in firm of retinol palmitate.
• A well fed person has a reserve to meet his needs for 6-9
months.
• Free Retinol is highly active nd toxic, and therefore is
transported in blood stream in combination with Retinol –
binding protein.
• In severe protein deficiency ,mobilization of liver retinol
reserves is impaired …… Why?
Vit.A Toxicity:
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Nausea
Vomiting
Sleep disorders.
Enlarged liver
Vit. A has teratogenic effects
What is Vit.A Deficiency?
• Vitamin A deficiency is a condition that results from
inadequate quantities of vitamin A in the body.
• Lack of vitamin A (vitamin A deficiency) can damage the
immune system, making people more likely to suffer from
infections.
• Severe vitamin A deficiency can lead to eye problems, poor
vision and irreversible blindness.
• Vitamin A deficiency is the major cause of blindness in
children.
Who is at risk of developing vitamin A deficiency ?
• Newborn babies who are not given collostrum (first breast
milk)
• Infants who are not breastfed
• Infants born or breastfed from mothers with vitamin A
deficiency
• Infants born with very low weight (under 2.5 Kilos)
• Children between 6 months and 6 years of age
• Children who are malnourished and suffer from measles,
diarrhoea and other infections
• School-age children, pregnant adolescent girls and elderly
people
• People of any age who are malnourished and do not have a
diet rich in vitamin A
What causes vitamin A deficiency?
• Vitamin A deficiency is caused by a poor diet that does not
contain enough foods rich in vitamin A to meet the body’s
needs.
• Oil or fat in the diet is needed to help the body absorb
vitamin A from foods.
• It is also caused by measles, diarrhoea and other infections
and repeated illnesses that block absorption and cause the
body to lose or use up stores of vitamin A more quickly.
Magnitude of Vitamin A Deficiency
• Contributing factor in 2.2 million deaths each year from
diarrhea and 1 million deaths from measles among
preschool children under five.
• Severe deficiency can also cause irreversible corneal
damage, leading to partial or total blindness.
• Vit.A can reduce by half the number of deaths due to
measles.
Magnitude of Vitamin A Deficiency
• Pre-school children
• Clinically deficient: 3 million (Asia and Africa)
• Subclinically deficient (low serum retinol): 100-140
million
• 250,000-500,000 become blind each year
• 90 % case fatality among those who become blind
• Pregnant women
• 25%-30% cases of night blindness reported in some
countries
Assessment of Vit.A Deficiency
WHO Criteria
(The presence of any one criteria should be considered as evidence of
Xerophthalmia problem in the community)
Criteria
Prevalence in population at ris
(6 months to 6 years)
Night Blindness
More than 1%
Bitot`s Spots
More than 0.5 %
Corneal xerosis/ulceration/Keratomalacia
More than 0.01%
Corneal ulcer
More than 0.05%
Serum Retinol less than 10 mcg/dl
More than 5%
What are the effects of vitamin A deficiency?
• Eye problems, poor vision and in severe cases, permanent
blindness.
• Diseases of the respiratory and digestive systems.
• Repeated illnesses, because the body’s defence mechanism is
low, and general poor health.
• Poor growth and development in children.
Manifestations of Vit.A Deficiency:
• Predominantly Ocular
• Extra-Occular
Xerophthalmia (Dry eye):
Comprises all the ocular manifestations of vit.A deficiency
ranging from night blindness to keratomalacia
Ocular manifestations
( Xerophthamia)
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Most common in children aged 1-3 years.
Related to weaning.
Often associated with PEM.
Risk factors include:
Ignorance
Faulty feeding practices.
Infections.
Ocular manifestations
( Xerophthamia)
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Night blindness
Conjunctival xerosis.
Bitot`s spots.
Corneal xerosis.
Keratomalacia..
Ocular Manifestations
( Xerophthamia)
Night blindness:
Inability to see in dim light.
Conjunctival xerosis:
Drying of the conjunctival surface.
Bitot’s spots:
Cheesy or foamy patches of keratinised cells.
Corneal xerosis:
Drying and keratinisation of the corneal surface; hazy, opaque
Appearance.
Keratomalacia:
Liquefaction of the cornea. It is a grave medical emergency.It is also
a major cause of Blindness.
(softening of the cornea).
Extra-ocular manifestations:
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Follicular hyperkeratosis.
Anorexia.
Growth retardation.
Increased child mortality and morbidity due to respiratory
and intestinal infections. .
How can vitamin A deficiency be treated?
• Effective treatment of vitamin A deficiency depends on early
identification of the problem. Blindness caused by severe
vitamin A deficiency is preventable but not curable.
• Treatment of severe vitamin A deficiency:
• A child with any signs of eye problems, such as night
blindness (chicken eyes) or dry eyes, needs urgent medical
attention and vitamin A supplements.
• • People suffering from vitamin A deficiency need to eat foods
rich in vitamin A and foods fortified with vitamin A.
• Proper treatment of diarrhoea, malnutrition, measles,malaria
and tuberculosis.
Treatment:
• Early stages:
200,000 IU or 110 mg of retinol palmitate. Orally on two
successive days.
• All children with corneal ulcers should be given vit.A.
Prevention and control:
• Short-term action. (Supplementation)
• Medium-term action. (Fortification)
• Long-term action. (Reduction of factors contributing to the
disease)
Interventions to Control VAD
• In 1999, only 10 countries provided two rounds of VA
supplementation with high coverage, this has increased to
over 50 countries by 2004.
• Between 1998 and 2004, UNICEF estimates that about
two million child deaths may have been prevented.
• Food Fortification
- A number of countries are
successfully fortifying foods with vitamin A (e.g. sugar,
maize flour, wheat) reaching large populations.
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VA Supplementation Coverage
Where VAD is a public health problem (U5MR>70)
70% or more
30 to 69%
Less than 30%
Percent of children aged 6-59 months who received at
least one vitamin A supplement within the last six months
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Source: UNICEF (2000)
No data available