Epidemiological & Nutrition
Transitions
International Development & Health
Hilary Term 2009
Proochista Ariana
Overview
• Epidemiological transitions with economic
growth
– Theory
– Idea of a ‘transition’
• New & resurgent diseases
• Nutritional transitions with economic growth
• Anthropometry
Points for Reflection
• How appropriate is the idea of a linear
transition when it comes to epidemiological
and nutritional changes accompanying
processes of development?
• What does anthropometry tell us about
health?
• How can political, economic, or social factors
help explain the dynamic changes in diseases
and nutrition?
Demographic Transition
Demographic Transition
• originally developed by demographers to
explain population changes in nineteenth
century Europe
• characterised by a shift from high birth rates
and high death rates to low birth rates and
low death rates
• with an intermediate period where the
decline in birth rates lags behind the decline in
death rates (leading to an overall increase in
the population)
(Source: Omran 1971)
USA 1900
Source: The following pyramid images were obtained from:
http://www.ageworks.com/course_demo/200/module2/module2b.htm#developing
USA 1960 and 2000
Mexico, 1995
Finland, 1996
Japan, 1996
Aging Population
18
World
More developed regions
Less developed regions
Least developed countries
China
16
14
Aged 65 or over (%)
12
10
8
6
4
2
0
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
Year
Source: Population Division of the Department of Economic and Social Affairs of the United
Nations Secretariat. World Population Prospects 2006 revision: http://esa.un.org/unpp.
2005
Dependency Ratio
• An index of the proportion of a population not
active in the labour force (and thereby
dependent) compared with those contributing
to the labour force (the productive element)
• The higher the ratio the greater the burden on
the productive element of the population for
upbringing (childhood dependency) and
pensions and aged care (old age dependency)
Old-Age Dependency Ratio
25
World
More developed regions
Less developed regions
Least developed countries
China
20
Ratio
15
10
5
0
1950
1955
1960
1965
1970
1975
1980
Year
1985
1990
1995
2000
2005
Child Dependency Ratio
90
80
70
60
Ratio
50
40
30
World
More developed regions
Less developed regions
Least developed countries
China
20
10
0
1950
1955
1960
1965
1970
1975
1980
Year
1985
1990
1995
2000
2005
Epidemiological Transition
“Conceptually, the theory of epidemiologic
transition focuses on the complex change in
patterns of health and disease and on the
interactions between these patterns and their
demographic, economic and sociologic
determinants and consequences.”
(Omran, 1971)
Epidemiological Transition
In sum, the theory suggests that with processes
of development, the disease burden shifts
from that of a communicable nature to noncommunicable with intermediate increases in
accidents and injuries
3 Stages of Transition
1. Age of Pestilence and Famine: high &
fluctuating mortality with low and variable life
expectancy (epidemics, famines, wars)
2. Age of Receding Pandemics: declining
mortality with fewer peaks & steady increase in
LE; population growth exponential
3. Age of Degenerative and Man-Made Diseases:
mortality continues to decline and stabilizes
contributing to rising LE (cancers and
cardiovascular diseases prevail)
Changing Pattern of Disease
• Decline of infectious diseases and an increase
in cancer and cardiovascular diseases
– Classical or Western Model (Europe, N America)
– Accelerated Transition Model (Japan)
– Contemporary or Delayed Model
Determinants of Transition
• Ecobiologic: ‘complex balance between disease
agents, the level of hostility in the environment
and the resistance of the host’
• Socioeconomic, political, & cultural: standards
of living, health habits and hygiene and nutrition
• Medical & public health: ‘preventive and curative
measures such as improved public sanitation,
immunization and the development of decisive
therapies’
(Source: Omran 1971)
Evidence in Support of Theory
• Infectious and parasitic diseases, such as
tuberculosis and malaria, remain the leading
causes of death in low income regions
• More developed regions have higher lifeexpectancies at birth and lower mortality rates
than those in sub-Saharan Africa
• Diseases that affect more developed countries
are predominantly non-communicable
Leading Causes of Death Today
Income group
NonCommunicable communicable Injuries
Low income
Lower middle
income
Upper middle
income
70
20
10
34
48
18
30
51
19
High Income
8
77
15
Global
54
33
13
Source: WHO 2006 Statistics
Causal Groupings
• Group I: Communicable, maternal, perinatal,
& nutritional conditions
• Group II: Non-communicable diseases
• Group III: Injuries
Future Transitions
• In 1990, the leading causes of disease burden were:
– Pneumonia
– Diarrhoeal disease
– Perinatal conditions
• In 2020, it is predicted that the leading causes will
include:
– Heart disease
– Depression
– Traffic Accidents
Transition?
• Recognition that the so-called ‘transition’ is
more complex and dynamic
• Not unidirectional as evidenced by reversals in
trends (e.g. TB) and coexistence of ‘stages’
• “the health and disease patterns of a society
evolve in diverse ways as a result of
demographic, socioeconomic, technological,
cultural, environmental and biological
changes” (Wahdan 1996)
Communicable Diseases
Risk Factors
• Biological (humans and pathogens)
– virulence
– adaptation
– resistance
• Environmental (changing eco-systems)
– reservoirs
– exposure
• Social, cultural, behavioural
• Medical technology
Biological Risks
• With the discovery and use of antimicrobials
and vaccines, it was assumed that infectious
diseases would disappear, but...
• Antigenic change and adaptation of infecting
organisms including emergence of drug
resistant strains (e.g. TB, malaria)
• Co-infections (e.g. HIV and TB)
• Immuno-suppression
• Malnutrition
Environmental Risks
• Changes in ecological balance
– Pathogens
– Vectors
– Reservoirs (intermediate hosts)
– hosts
• Niches and reservoirs created
– Stagnant water
– Garbage dump sites
– Deforestation
Social, Cultural, Behavioural
• Changing lifestyles (live and work)
• Changing social values and expectations
• Changing social networks & community
cohesion
• Changing patterns of mobility (work, trade,
leisure)
• Improvements in education
• Changing role of women
Medical Technology
•
•
•
•
•
Quantity and distribution
Accessibility and acceptability
Quality and kinds of services
Curative versus preventive
Unintended negative consequences
– Side-effects
– Superimposed infections
– Drug resistance
Leading Communicable Diseases
1.
2.
3.
4.
5.
Lower Respiratory Infections
HIV/AIDS
Diarrheal Diseases
Tuberculosis
Malaria
Routes of Transmission
•
•
•
•
•
•
•
Aerosol
Sexual transmission/blood transmission
Faecal-oral (water, sanitation, and hygiene)
Vector-borne
Skin contact
Vertical transmission
Iatrogenic
Trends in Communicable Diseases
Rank
1
2
3
4
5
6
7
8
9
10
11
12-17
Worldwide mortality due to infectious diseases
Percentage of
Cause of death
Deaths 2002
all deaths
All infectious diseases
14.7 million
25.90%
Lower respiratory infections
3.9 million
6.90%
HIV/AIDS
2.8 million
4.90%
Diarrheal diseases[11]
1.8 million
3.20%
Tuberculosis (TB)
1.6 million
2.70%
Malaria
1.3 million
2.20%
Measles
0.6 million
1.10%
Pertussis
0.29 million
0.50%
Tetanus
0.21 million
0.40%
Meningitis
0.17 million
0.30%
Syphilis
0.16 million
0.30%
Hepatitis B
0.10 million
0.20%
Tropical diseases (6)[12]
0.13 million
0.20%
Deaths 1993
16.4 million
4.1 million
0.7 million
3.0 million
2.7 million
2.0 million
1.1 million
0.36 million
0.15 million
0.25 million
0.19 million
0.93 million
0.53 million
1993 Rank
32.20%
1
7
2
3
4
5
7
12
8
11
6
9, 10, 16-18
WHO 1995 and 2004
Malaria
• There were 247 million cases of malaria in
2006, causing about 880,000 deaths, mostly
among African children
• Drug resistance to commonly used
antimalarial drugs has spread very rapidly
• increasing mosquito resistance to key
insecticides DDT and pyrethroids, particularly
in Africa
Global distribution of malaria
(1900 - 2002)
Hay et al, 2004
Tuberculosis
• There were an estimated 14.4 million
prevalent cases of TB in 2006 & 0.5 million
cases of MDR-TB
• 9.2 million new cases (139 per 100 000
population)
• Sub-Saharan Africa has the highest incidence
rate per capita (363 per 100 000 population).
• India & China have the highest absolute
numbers of cases
Successful vector-borne disease
control/elimination programs
Gubler, 1998
Emerging Infectious Diseases
• Jones et al (2008) estimate the emergence of
335 infectious diseases between 1940 and 2004
• 54.3% are bacterial or rickettsial and include
drug-resistant bacterial strains
• 25.4% are from Viral or prion pathogens
• 10.7% from protozoa, 6.3% from fungi and 3.3%
from helminths
Emerging Infectious Diseases
Trends
Jones et al, 2008
Geographic origins of EID
Jones et al, 2008
Global distribution of relative risk
of an EID
Jones et al, 2008
Examples of Emerging or
Resurgent Infections
•
•
•
•
•
•
Human Immunodeficiency Virus (HIV)
Severe Acute Respiratory Syndrome (SARS)
Avian Influenza
Ebola Hemorrhagic Fever
Dengue
TB/MDRTB
Avian Influenza:
Geographical Distribution
WHO, 2009
Avian Influenza Epidemiology
• Influenza virus is normally species-specific
• Hundreds of avian influenza strains in birds
but 4 are known to have infected humans the
most important of which is H5N1
• First documented outbreak of H5N1 was in
Hong Kong in 1997
• Close contact with dead or sick birds is the
principal source of infection
WHO, 2009
Dengue and Dengue Hemorrhagic
fever
Dengue
• Dengue is a mosquito-borne infection that causes a severe
flu-like illness, and sometimes a potentially lethal
complication called dengue haemorrhagic fever.
• Global incidence of dengue has grown dramatically in
recent decades. About two fifths of the world's population
are now at risk.
• Dengue is found in tropical and sub-tropical climates
worldwide, mostly in urban and semi-urban areas.
• Dengue haemorrhagic fever is a leading cause of serious
illness and death among children in some Asian countries.
• There is no specific treatment for dengue, but
appropriate medical care frequently saves the lives of
patients with the more serious dengue haemorrhagic fever.
• The only way to prevent dengue virus transmission is to
combat the disease-carrying mosquitoes.
WHO, 2009
Communicable Diseases
• Remain a prevailing problem globally
– Not controlled by vaccines
– Not ameliorated by antibiotics
• Emergence of new diseases
– Ecological changes
– Rapid adaptation of pathogens
• Resurgence of ‘old’ diseases
– Breakdown of infrastructure
– Increased susceptibilities
Possible Reasons
• Demographic
– Population growth
• Economic
– Poverty
– Inequality
• Political
– Public health programmes
• Infrastructural
– Water, sanitation, housing conditions
Non-Communicable Diseases
Risk Factors
• Biological
• Environmental
– Pollutants and toxins
– Stress
• Social, cultural, behavioural
– Nutrition
– Sedentary lifestyles
– Smoking
• Medical technology
Environmental Risks
• Toxins and Pollutants
– Cancers
– Respiratory problems
– Allergies (?)
• Stress
– Cardiovascular problems
– Unhealthy behaviours
Social, Cultural, Behavioural
• Changing diets
• Changing activities
– Types of employment
– Types of leisure
• Loss of social networks and supports
• Addictive behaviours (e.g. smoking, alcohol)
Medical Technology
• Expansion of diagnostic capacity
• Expansion of therapeutics
• Pharmaceuticals
– Side effects
– Over-dose
– Adverse interactions
Leading Non-Communicable
Diseases
•
•
•
•
Cardiovascular
Cancer
Respiratory
Digestive
Global Leading Causes of Death
(2004)
Source: WHO Fact Sheet 310, 2008
Source: WHO Fact Sheet 310, 2008
Non-communicable Diseases
Abegunde, 2007
Non-communicable Diseases
Abegunde, 2007
Cardiovascular Diseases
• More people die annually from CVDs than
from any other cause
• An estimated 17.5 million people died from
CVDs in 2005 (30% of all global deaths)
• Over 80% of CVD deaths take place in lowand middle-income countries
Global Burden of Cancer
Stewart et al, 2003
Trends in Lung Cancer
McKay et al, 2009
Trends in Lung Cancer
Stewart et al, 2003
Trends in Breast Cancer
Stewart et al, 2003
Global Trends in Childhood Cancers
McKay et al, 2009
Risk Factors for NCDs
• Increasing average life expectancy and an
increase in the prevalence of modifiable risk
factors:
– unhealthy nutritional intake
– sedentary lifestyles
– smoking
Risk of Tobacco
Source: World Health Statistics 2008
Tobacco Use
Source: World Health Statistics 2008
Risk Factors & Burden of Disease
Source: Pomerleau et al 2002
Accidents and Injuries
Road Traffic Accidents
• Road traffic accidents rank as the 11th leading
cause of death and account for 2.1% of all
deaths globally
– kill 1.2 million people a year or an average
– injure or disable between 20 million and 50
million people a year
• 90% of road traffic deaths occur in low-income
and middle-income countries
Violence
• Each year, more than 1.6 million people
worldwide lose their lives to violence
• Violence is among the leading causes of death
for people aged 15–44 years worldwide,
accounting for about 14% of deaths among
males and 7% of deaths among females
• Of the 1.6 million violence-related deaths
worldwide (including those from conflict and
suicide) that occur each year, 90% happen in
low- and middle-income countries
Transition?
Double Burden of Disease
• Concurrence of both communicable and noncommunicable diseases
• Infection is responsible for 25% of cancers in
the developing world compared with 10% in
the developed world
Triple Burden of Disease
• Communicable, non-communicable, and
socio-behavioural
• Increasing recognition of burden of mental
illnesses
• Aging population and chronic diseases of
lifestyle
• Tobacco: “By 2020, tobacco is expected to kill
more people than any single disease, even
HIV/AIDS”
Source: Global Burden of Disease 2004
Cause of Death by Income Level 2004
100%
90%
% of total deaths
80%
70%
60%
Injries
50%
Non-communicable
Communicable
40%
30%
20%
10%
0%
High
Upper Middle
Lower Middle
Income Level
Low Income
Source: Global Burden of Disease 2004
Source: Deaton 2005
5 stage model of Epi Transition
Stage
Characteristics
Age of pestilence and famine
Infectious and nutritional related
cardiomyopathies; Rheumatic heart disease
Age of receding pandemics
Hypertensive cardiovascular disease
Haemorrhagic strokes
Age of degenerative and man-made
diseases
Haemorrhagic and ischemic stoke, ischemic
heart disease, diabetes and obesity
Onset at younger age
Atherosclerotic cardiovascular disease; Onset of
chronic disease at older ages – delay occurs due
to improved prevention and treatment
Social upheaval causes an increase in the
prevalence of chronic disease at younger ages;
Re-emergence of mortality due to infectious
disease and rheumatic heart disease
Age of delayed degenerative diseases
Age of health regression and social
upheaval
Source: Yusuf et al., (2001)
Delayed Degenerative Diseases
• The age of delayed degenerative disease is
characterised by an increase in the average life
expectancy and an increase in the age of
onset for chronic disease. This stage includes
regions with relatively advanced health care
systems such as North America, Australia and
Western Europe illustrate this stage
Health Regression & Social
Upheaval
• re-emergence of mortality due to
communicable disease in addition to noncommunicable disease
• Average life expectancy decreases and an
increase in the prevalence of noncommunicable diseases is seen at younger
ages
Social Determinants
• conditions in which people are born, grow,
live, work, and age
• access to health care, schools and education,
their conditions of work and leisure, their
homes, communities, towns, or cities
• unequal living conditions are the consequence
of poor social policies and programmes, unfair
economic arrangements, and bad politics
Conditions of Life
• Different Exposures to disease-causing
influences in early life
• Different Vulnerabilities
• Differences in ability to cope (material,
psychosocial, behavioural)
Nutrition Transition
Nutrition Measures
• Anthropometric
– Weight-for-height (wasting)
– Height-for-age (stunting)
– Body mass index
– Adult height
• Dietary consumption
• Micronutrient levels
Under-Nutrition
• Physical and mental lethargy
• Compromised immune system and increased
susceptibility to infections
• Increased frequency and/or severity of
morbidities and enhanced risk of mortality
• Compromised cognitive development
Over-Nutrition
• Blood pressure, cholesterol, triglycerides, and
insulin
• Type 2 Diabetes
• Cardiovascular diseases and fatalities
• Cancer of the breast, colon, prostrate,
endometroium, kidney and gallbladder
• Contributes to osteoarthritis, respiratory
difficulties, musculoskeletal problems,
infertility
Nutrition Transition
• Hunting & gathering: Plants, low-fat wild
animals; varied diet
• Famine: Cereals predominant; diet less varied
• Receding famine: Fewer starchy staples; more
fruits, vegetables, animal protein; low variety
• Degenerative disease: More fat, sugar &
processed foods; less fibre
• Behavioural change: Less fat and processing;
increased carbohydrates, fruits and vegetables
Nutrition Transition
Source: Mike Rayner (WHO, SDE/NHD, 2000)
Shifts in Diets
• increases in the consumption of foods sourced
from animals, caloric sweeteners and fat
• Between 1970 and 1995 the world
consumption of calories from starchy roots
and pulses fell by 30% while the proportion of
calories from meat increased by a third and
from vegetable oils by almost half
• Over the same period the consumption of
meat and poultry doubled in Asian countries
while the consumption of vegetables halved
Source: Pomerleau et al 2002
Dietary Energy Supply, USA
WHO Global Database on
Body Mass Index
Physical Activity
• shifts away from physically demanding
economic activities (e.g. farming, mining and
forestry) towards more sedentary activities
(e.g. office based, assembly lines)
• Technological innovation leads to decreased
activity in previously physically demanding
jobs
• Leisure activities are increasingly sedentary in
nature
Global Obesity Epidemic
• According to the WHO, over 1 billion adults are
overweight, 300 million of whom are obese
• Obesity ranges from under 5% in China to over
75% in urban Samoa
• Estimated 17.6 million children under five are
estimated to be overweight worldwide
• In the US, the number of overweight children
has doubled and the number of overweight
adolescents has trebled since 1980
Source: De Onis 2000
Increase in Obesity
• in many developing regions obesity
prevalence is outstripping rates in the
developed world
• The rate of increase in obesity among adults in
Asia, North Africa and Latin America are
between two and five times of the rate of
increase in Northern America
Transition to Obesity
• Shift to Western dietary habits and a
proliferation of fast-food chains
• Higher energy-dense foods, larger portion size
and an increase in the consumption of sugar
rich soft drinks
• In combination with increasingly automated
and sedentary lifestyles
China (1991-2004)
Source: Dearth-Wesley et al 2008
Transition?
Nutrition related non-communicable disease risk
among the well off population appear
concurrent with simultaneous persistence of
under-nutrition and low food security among
the poorer populations of the same country
Guatemala Case
Anthropometry
Anthropometric Measures
• Weight-for-Height: An indicator of acute
malnutrition or ‘wasting’
• Height-for-Age: An indicator of chronic
malnutrition or ‘stunting’
• Weight-for-Age: one of the first measures of
nutritional status and remains the measure
most closely correlated to fatal health (Gomez
et al 1956)
Cut offs
• States of malnutrition are classified using WHO’s
recommended two standard deviation cut-off
points: “In general, abnormal anthropometry is
statistically defined as an anthropometric value
below -2 standard deviations (SD) or Z-scores
(<2.3rd percentile), or above +2 SD or Z-scores
(>97.7th percentile) relative to the reference
mean or median. These cut-offs define the
central 95% of the reference distribution as the
“normality” range” (WHO, 1995 p.181).
International Standard
• 1978 National Center for Health Statistics
(NCHS) reference curves for height-for-age,
weight-for-age, and weight-for-height
• Sample of American formula-fed infants
• Restricted socio-economic and genetic
background
• Intervals of measurement preclude precise
curve fitting
• Positively skewed weight distribution
NCHS versus WHO Standards
Source: de Onis 2006
Categories of Undernutrition
• Stunting: “the process of failure to reach
linear growth potential as a result of
inadequate nutrition and/or public health”;
• Wasting: “describes a recent or current severe
process leading to significant weight loss,
usually as a consequence of acute starvation
and/or disease”
• Underweight: is simply defined as “low weight
for age”
Stunting
• WHO contrasts stunting with shortness which
they define as “a descriptive term for low
height-for-age, without implication of cause”
(WHO, 1995 p.422)
• “a high prevalence of low height-for-age
indicates poor nutrition, high morbidity from
infectious disease, or-most often-both”
(WHO)
Wasting
• “A high prevalence of low weight-for-height is
indicative of severe recent or current events,
for example starvation or outbreaks of
infectious diseases such as diarrhoea or
measles” (WHO, 1995 p.181).
Body Mass Index
Underweight
Severe thinness
Moderate thinness
Mild thinness
<18.50
<16.00
16.00 - 16.99
17.00 - 18.49
Normal range
18.50 - 24.99
Overweight
Pre-obese
Obese
≥25.00
25.00 - 29.99
≥30.00
Obese class I
30.00 - 34-99
Obese class II
35.00 - 39.99
Obese class III
≥40.00
<18.50
<16.00
16.00 - 16.99
17.00 - 18.49
18.50 - 22.99
23.00 - 24.99
≥25.00
25.00 - 27.49
27.50 - 29.99
≥30.00
30.00 - 32.49
32.50 - 34.99
35.00 - 37.49
37.50 - 39.99
≥40.00
Proxy for Malnutrition
• Initially anthropometry was developed and
applied as an easy way to approximate clinical
malnutrition in the field
• Changes in body composition signify one
manifestation of malnutrition which can be
readily measured
• However, anthropometry alone is insufficient to
define malnutrition (which requires clinical
assessment)
• Rather it identifies individuals at greater risk for
malnutrition (Trowbridge FL, 1979)
Validity
• Relies on evidence linking outward expression
of stature to physiological processes
• Concurrent validity: the ability of the
anthropometric measures to correspond to
clinical assessments of malnutrition
• Predictive validity: the ability of the indicator
to predict future morbidity and mortality
Other Implications
• Even without extra susceptibility to disease,
stunting or wasting may have consequences
for:
– Energy
– Productivity
– Feelings of well-being
– Shame, humiliation or pride & self-confidence
– Quality of life
Childhood stunting, severe
wasting, and underweight 2005
Black et al, 2008
Prevalence of Stunting
(Source: de Onis et al 2000)
Trends in Stunting
(Source: de Onis et al 2000)
Height-for-age and attained height
Victora et al, 2008
Height-for-age and attained
schooling
Victora et al, 2008
Height-for-age and offspring
birthweight
Victora et al, 2008
Height-for-age and BMI
Victora et al, 2008
Height-for-age and glucose
concentration
Victora et al, 2008
Height-for-age and systolic blood
pressure
Victora et al, 2008
Stunting and dietary diversity
Black et al, 2008
Global deaths and disease burden
attributable to undernutrition
Black et al, 2008
Micronutrients
Zinc
Vitamin D
Riboflavin
Thiamin
Vitamin E
Magnesium
Iodine
Vitamin B6
Manganese
Folate
Iron
Vitamin B12
Vitamin A
Vitamin C
Cobalt
Phosphorus
Cobalamin
Selenium
Niacin
Vitamin K
Chromium
….are endemic almost throughout the world including in most
emergency-affected populations….
Iodine Deficiency
•
•
•
•
Goiter
Hypothyroidism
Cretinism
Mental retardation
Distribution of Iodine Deficiency
WHO, 2004
Sources of Iodine
• Iodized salt
• Seafood is naturally rich
in iodine; Cod, sea bass,
haddock, and perch are
good sources.
• Kelp is the most common
vegetable seafood that is
a rich source of iodine.
• Dairy products also
contain iodine. Other
good sources are plants
grown in iodine-rich soil.
Iodine Toxicity
• Chronic toxicity may develop when intake is > 1.1
mg/day.
• Some people who ingest excess amounts of iodine,
particularly those who were previously deficient, develop
hyperthyroidism (Jod-Basedow phenomenon).
• Paradoxically, excess uptake of iodine by the thyroid
may inhibit thyroid hormone synthesis (called WolffChaikoff effect). Thus, iodine toxicity can eventually
cause iodide goiter, hypothyroidism, or myxedema.
• Very large amounts of iodide may cause a brassy taste
in the mouth, increased salivation, GI irritation, and
acneiform skin lesions.
Vitamin A Deficiency
• Bitot spots - areas of
abnormal squamous
cell proliferation and
keratinization of the
conjunctiva
• Blindness
• Dry skin, dry hair,
pruritus, broken
fingernails
Distribution of Vitamin A
Deficiency
WHO, 2004
Prevalence of vitamin A deficiency
in children <5
Black et al, 2008
Sources of Vitamin A
http://ods.od.nih.gov/factsheets
Vitamin A Toxicity
• Hypervitaminosis A refers to high storage levels of vitamin A in
the body that can lead to toxic symptoms.
• Four major adverse effects: birth defects, liver abnormalities,
reduced bone mineral density that may result in osteoporosis,
and central nervous system disorders.
• Toxic symptoms can also arise after consuming very large
amounts of preformed vitamin A over a short period of time.
• Signs of acute toxicity include nausea and vomiting,
headache, dizziness, blurred vision, and muscular
uncoordination.
• Can occur when large amounts of liver are regularly
consumed and from taking excess amounts of the nutrient in
supplements.
Iron Deficiency
• Feeling tired and weak
• Decreased work and
school performance
• Slow cognitive and social
development during
childhood
• Difficulty maintaining body
temperature
• Decreased immune
function, which increases
susceptibility to infection
• Glossitis (an inflamed
tongue); Koilonychia
(spoon-shaped fingernails)
Anemia in Pre-schoolers
WHO, 2008
Anemia in Pregnant Women
WHO, 2008
Anemia in Women of
Reproductive Age
WHO, 2008
Sources of Iron
• Dried beans; Dried fruits
• Eggs (especially egg
yolks)
• Iron-fortified cereals
• Liver
• Lean red meat (especially
beef)
• Oysters
• Poultry
• Salmon
• Tuna
• Whole grains
•
•
•
Iron from vegetables, fruits,
grains, and supplements is
harder for the body to absorb.
Dried fruits: prunes, raisins,
apricots, Legumes: lima beans,
soybeans, dried beans and
peas, kidney beans, Seeds,
almonds, Brazil nuts;
Vegetables: broccoli, spinach,
kale, collards, asparagus,
dandelion greens; Whole grains:
wheat, millet, oats, brown rice
If you mix some lean meat, fish,
or poultry with beans or dark
leafy greens at a meal, you can
improve absorption of vegetable
sources of iron up to three
times.
Iron Toxicity
• children can sometimes develop iron
poisoning by swallowing too many iron
supplements.
• Symptoms of iron poisoning include:
Fatigue; Anorexia; Dizziness; Nausea;
Vomiting; Headache; Weight loss;
Shortness of breath; Grayish color to the
skin
Pellagra - niacin deficiency
• populations receiving maize
ration without access to
legumes - maize is poor source
of niacin
• known as 3D’s: dermatitis,
diarrhoea and dementia
• skin irritation around
symmetrical sun-exposed
areas, especially neck (“Casal’s
necklace”)
Sources of Niacin
• dairy products,
poultry, fish, lean
meats, nuts, eggs,
legumes and enriched
breads and cereals
Niacin Toxicity
• Large doses of niacin can cause liver
damage, peptic ulcers, and skin rashes.
Even normal doses can be associated with
skin flushing.
PELLAGRA Dermatitis
Beri-beri: Thiamin deficiency
• populations consuming
polished rice (nonparboiled rice)
• wet beri-beri (anorexia,
oedema, increase in pulse
and tenderness); dry beriberi (muscle weakness,
dysfunction of nervous
system
Thiamine Sources
• fortified breads,
cereals, pasta, whole
grains (especially
wheat germ), lean
meats (especially
pork), fish, dried
beans, peas, and
soybeans
Scurvy - Vitamin C deficiency
• populations with no
access to fruit and
vegetables or entirely
reliant on rations as
source of food
• fatigue, swollen and
bleeding gums,
haemorrhage, slow
healing of wounds
SCURVY – Bleeding gums/inability to walk
Vitamin C Sources
• All fruits and vegetables
contain some amount of
vitamin C.
• Foods that tend to be the
highest sources of vitamin C
include green peppers, citrus
fruits and juices, strawberries,
tomatoes, broccoli, turnip
greens and other leafy greens,
sweet and white potatoes, and
cantaloupe.
• Other excellent sources
include papaya, mango,
watermelon, brussels sprouts,
cauliflower, cabbage, winter
squash, red peppers,
raspberries, blueberries,
cranberries, and pineapples.
Vitamin C Toxicity
• Vitamin C toxicity is very rare, because the
body cannot store the vitamin.
• However, amounts greater than 2,000
mg/day are not recommended because
such high doses can lead to stomach
upset and diarrhea.
Riboflavin deficiency
• Angular stomatitis
• Sore throat
• Swelling of mucus
membranes
• Anemia
• Skin disorders
Riboflavin Source
• Lean meats, eggs,
legumes, nuts, green
leafy vegetables,
dairy products, and
milk provide riboflavin
in the diet. Breads
and cereals are often
fortified with
riboflavin.
Riboflavin Toxicity
• Because riboflavin is a water-soluble
vitamin, leftover amounts leave the body
through the urine. There is no known
poisoning from riboflavin.
Zinc deficiency
• Zinc deficiency is characterized by growth
retardation, loss of appetite, and impaired immune
function.
• In more severe cases, zinc deficiency causes hair
loss, diarrhea, delayed sexual maturation,
impotence, hypogonadism in males, and eye and
skin lesions.
• Weight loss, delayed healing of wounds, taste
abnormalities, and mental lethargy can also occur.
National risk of zinc deficiency in
children <5
Black et al, 2008
Zinc Sources
• High-protein foods contain high amounts
of zinc. Beef, pork, and lamb contain more
zinc than fish.
• The dark meat of a chicken has more zinc
than the light meat.
• Other good sources of zinc are peanuts,
peanut butter, and legumes.
Zinc Toxicity
• Zinc supplements in large amounts may
cause diarrhea, abdominal cramps, and
vomiting, usually within 3 - 10 hours of
swallowing the supplements. The
symptoms go away within a short period of
time after stopping the supplements.
Type I and II Deficiencies
TYPE I:
iron, copper, manganese, iodine,
selenium, calcium, thiamine,
riboflavin, pyridoxine, folate,
nicotinic acid ascorbic acid,
retinol, tocopherol (E), vitamin D
and K
•
•
•
•
•
Growth continues, anthropometric
abnormality late in deficiency
Specific clinical signs develop
Body has store
Specific enzymes affected
Diagnosed by biochemical tests
TYPE II:
potassium, sodium, magnesium,
zinc, phosphorus, protein,
nitrogen, essential amino acids,
oxygen, water
•
•
•
•
•
•
•
Growth failure
No specific clinical signs
No body store
Affects metabolism
No specific biochemical abn.
Diagnosed by anthropometry
Anorexia response
Thank You