Epidemiological & Nutrition Transitions

International Development & HealthHilary Term 2009Proochista 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

0

2

4

6

8

10

12

14

16

18

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

Year

Aged 65 or over (%)

World

More developed regions

Less developed regions

Least developed countries

China

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.

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

0

5

10

15

20

25

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

Year

Ratio

World

More developed regions

Less developed regions

Least developed countries

China

Child Dependency Ratio

0

10

20

30

40

50

60

70

80

90

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

Year

Ratio

World

More developed regions

Less developed regions

Least developed countries

China

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 non-communicable with intermediate increases in accidents and injuries

3 Stages of Transition1. 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 life-expectancies at birth and lower mortality rates than those in sub-Saharan Africa

• Diseases that affect more developed countries are predominantly non-communicable

Income group CommunicableNon-

communicable Injuries

Low income 70 20 10Lower middle income 34 48 18Upper middle income 30 51 19

High Income 8 77 15

Global 54 33 13

Leading Causes of Death Today

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. Lower Respiratory Infections2. HIV/AIDS3. Diarrheal Diseases4. Tuberculosis5. 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 Cause of death Deaths 2002Percentage of

all deathsDeaths 1993 1993 Rank

All infectious diseases 14.7 million 25.90% 16.4 million 32.20%1 Lower respiratory infections 3.9 million 6.90% 4.1 million 12 HIV/AIDS 2.8 million 4.90% 0.7 million 73 Diarrheal diseases[11] 1.8 million 3.20% 3.0 million 24 Tuberculosis (TB) 1.6 million 2.70% 2.7 million 35 Malaria 1.3 million 2.20% 2.0 million 46 Measles 0.6 million 1.10% 1.1 million 57 Pertussis 0.29 million 0.50% 0.36 million 78 Tetanus 0.21 million 0.40% 0.15 million 129 Meningitis 0.17 million 0.30% 0.25 million 8

10 Syphilis 0.16 million 0.30% 0.19 million 1111 Hepatitis B 0.10 million 0.20% 0.93 million 6

12-17 Tropical diseases (6)[12] 0.13 million 0.20% 0.53 million 9, 10, 16-18

Worldwide mortality due to infectious diseases

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 low- and 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 non-communicable 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

Source: Global Burden of Disease 2004

Source: Deaton 2005

5 stage model of Epi TransitionStage Characteristics

Age of pestilence and famine Infectious and nutritional related cardiomyopathies; Rheumatic heart disease

Age of receding pandemics Hypertensive cardiovascular diseaseHaemorrhagic strokes

Age of degenerative and man-made diseases

Haemorrhagic and ischemic stoke, ischemic heart disease, diabetes and obesity Onset at younger age

Age of delayed degenerative diseases Atherosclerotic cardiovascular disease; Onset of chronic disease at older ages – delay occurs due to improved prevention and treatment

Age of health regression and social upheaval

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

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 non-communicable disease

• Average life expectancy decreases and an increase in the prevalence of non-communicable 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 IndexUnderweight <18.50 <18.50 Severe thinness <16.00 <16.00 Moderate thinness 16.00 - 16.99 16.00 - 16.99 Mild thinness 17.00 - 18.49 17.00 - 18.49

Normal range 18.50 - 24.9918.50 - 22.9923.00 - 24.99

Overweight ≥25.00 ≥25.00

Pre-obese 25.00 - 29.9925.00 - 27.4927.50 - 29.99

Obese ≥30.00 ≥30.00

Obese class I 30.00 - 34-9930.00 - 32.4932.50 - 34.99

Obese class II 35.00 - 39.9935.00 - 37.4937.50 - 39.99

Obese class III ≥40.00 ≥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

Vitamin AVitamin A

ThiaminThiamin RiboflavinRiboflavin

NiacinNiacinFolateFolate

ManganeseManganese

MagnesiumMagnesium

IronIron

IodineIodine

CobalaminCobalamin

CobaltCobaltZincZinc

Vitamin CVitamin C

Vitamin EVitamin E

Vitamin DVitamin D

Vitamin KVitamin K

Vitamin BVitamin B66

Vitamin BVitamin B1212

SeleniumSelenium

ChromiumChromium

PhosphorusPhosphorus

….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 Wolff-Chaikoff 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 ATable 1: Selected animal sources of vitamin AFood Vitamin A (IU) %DVLiver, beef, cooked, 3 ounces 27,185 545Liver, chicken, cooked, 3 ounces 12,325 245Milk, fortified skim, 1 cup 500 10Cheese, cheddar, 1 ounce 284 6Milk, whole (3.25% fat), 1 cup 249 5

226 5

Table 2: Selected plant sources of vitamin A (from beta-carotene)Food Vitamin A (IU) %DV

22,567 45013,418 27011,458 230

9,558 1908,666 175

Vegetable soup, canned, chunky, ready-to-serve, 1 cup 5,820 115Cantaloupe, 1 cup cubes 5,411 110Spinach, raw, 1 cup 2,813 55

2,063 401,651 35

Papaya, 1 cup cubes 1,532 30Mango, 1 cup sliced 1,262 25Oatmeal, instant, fortified, plain, prepared with water, 1 cup 1,252 25

1,050 20Tomato juice, canned, 6 ounces 819 15

473 10Peach, 1 medium 319 6

313 6

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 (non-parboiled rice)

• wet beri-beri (anorexia, oedema, increase in pulse and tenderness); dry beri-beri (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