Micronutrient deficiencies can cause visible and dangerous health conditions, but they can also lead to less clinically notable reductions in energy level, mental clarity and overall capacity. This can lead to reduced educational outcomes, reduced work productivity and increased risk from other diseases and health conditions.

1. Micronutrients
Public Health Nutrition Course
Dr Amna Rehana Siddiqui
February 25, 2023

2. Objectives
A. Describe Micronutrient Deficiency (MND)
B. Explain the vulnerable groups for MND
C. Describe the strategies to address MND

3. What are Micronutrients?
• Trace elements and vitamins, named together
micronutrients (MNs), are essential for human
metabolism.
• Required in minute amounts to for performance
of body functions like digestion, absorption,
metabolism and growth.
• Research studies show the value of MNs in
common pathologies, with significant deficiencies
impacting the outcome.

4. Classification of Vitamins

5. Water and Fat soluble Vitamins
Water Soluble Fat Soluble
Absorption Directly to blood Lymph via
chylomicrons
Transport Free Require Carrier
Storage Circulate freely In cells, fatty
tissue, liver
Excretion In urine Stored in Fat cells
Toxicity Less likely More likely
Requirements Every 2-3 days Every week

6. Minerals as Micronutrients
Essential to human health & obtained from diet
Inorganic elements that cant be broken down
Plants get minerals from the soil they grow in,
and humans obtain minerals from water, eating
plants, and animal products.
The mineral content of soil and water varies
from place to place,
Mineral composition of foods and water differs
based on geographic location.

7. Classification of Minerals

8. A form of under-nutrition that occurs when intake or
absorption of vitamins and minerals is too low to sustain
good health & development in children and normal
physical and mental function in adults.
Causes include poor diet, disease, or increased
micronutrient needs not met during pregnancy and
lactation
Micronutrient deficiency:
hidden hunger

10. Causes of hidden hunger
• Poor diet is a common source of hidden
hunger.
• Diets based mostly on staple crops, such as
maize, wheat, rice, and cassava, which provide
a large share of energy but relatively low
amounts of essential vitamins and minerals,
frequently result in hidden hunger.

11. Individual to Population level effects:
Economic Development

12. A continuum from deficiency to excess

15. Common determinants of malnutrition
• Poverty
• Lack of purchasing power
• Lack of access to nutritious food
• Household food insecurity
• Suboptimal breastfeeding
• Poor complementary feeding practices
• Childhood infections
• Low maternal education

16. Causes of MND
• Poor diet: staple crops (maize, wheat, rice, and
cassava), which provide energy but are low in
vitamins & minerals: hidden hunger.
• Food prices and preferences shaped by
culture; peer pressure; geographical,
environmental, and seasonal factors.
• When food prices rise, consumers tend to
continue with staple foods while cutting intake
of non-staple foods containing micronutrients

17. Causes of MND -contd
• Knowledge on balanced diet, affordability and access
to nutritious foods such as animal-source foods (meat,
eggs, fish, and dairy), fruits, or vegetables, esp in
LMIC. In non-emergency situations, poverty limits
access to adequate nutritious foods.
• Impaired absorption: infection or a parasite,
increased losses.
• Diet affecting absorption. Fat-soluble vitamins such as
vitamin A are best absorbed when consumed with
dietary fat, while consumption of compounds like
tannins/phytates can inhibit iron absorption.
• Alcohol consumption interferes with absorption of
micronutrients.

18. Main Cause of hidden hunger: Poverty
The United Nation’s Millennium Development
Goals include eradicating extreme poverty and
hunger as their priority goal
Acute respiratory infection and diarrhea are the
most common causes of infant mortality, and
MNDs contribute greatly to the immune
response.

20. Examples of Micronutrient Deficiencies
• Iron deficiency
• Iodine deficiency
• Vitamin A deficiency
• Vitamin C deficiency

21. Source: Black et al. (2013).

22. Iron
• Iron a mineral that is an essential component of
hemoglobin, myoglobin, enzymes, and cytochromes, is
needed for oxygen transport and cellular respiration
• Iron is critical for optimal growth and cognitive
function, endocrine & immune function
• Two forms of iron exist, namely heme and nonheme.
• Heme iron is found in animal sources, whereas non-
heme iron is found in plants and used in fortification.
• Neither form of iron is highly bioavailable; heme iron
bioavailability is estimated to be 12–25%, and non-
heme iron is <5% bioavailable
• Anemia during pregnancy is a risk factor for mortality
(PPH), and children born to mothers with iron
deficiency have low iron stores

23. Iodine
• Required for synthesis of thyroid hormone.
• About 60% of the total body pool of iodine is stored in
the thyroid gland. Thyroid hormone is necessary for
regulation of human growth and development.
• Iodine in foods is dependent on soil concentration,
irrigation, and farming. The iodine content of fish and
seaweed is also highly variable
• Iodine absorption and utilization can be impaired by
the presence of goitrogens
• Dietary supplements is generally either in a salt or
organic form
• Pregnant females and infants at risk

24. Vitamin A
• Needed for vision, cell differentiation, immune- function,
reproduction, organ and bone formation and growth.
• Animal sources in the diet preformed as retinol or retinyl
esters, or from provitamin A carotenoids in plant sources.
• Vitamin A deficiency (VAD) is related to increased rates
and severity of infections, primary cause of childhood
morbidity and mortality in the developing world.
• VAD is the leading cause of preventable blindness in
children, causes xerophthalmia, & ocular manifestations
like night blindness, Bitot’s spots, and corneal ulcerations
and lesions, cluster in families, communities, & regions
• Supplementation is a strategy

25. Folic Acid
• Folate deficiency causes megaloblastic or
macrocytic anemia and increases the likelihood
for pregnancies affected by neural tube defects
• Folic acid supplementation in the peri-
conceptional period unequivocally reduces the
occurrence of neural tube defects
• Reproductive age females should be screened
and treated for anemia, micronutrient
deficiencies and obesity.
• Folic acid supplementation should be given to all
prospective and antenatal mothers.

26. Zinc
• Cellular metabolism, and for the activity of more than 200 enzymes
• Immune system function, cell division, and protein and DNA synthesis
• Normal growth & development from in utero until puberty.
• The human body has no long-term storage system for zinc, so
consistent dietary intake is needed to sustain all of these functions
and maintain the relatively small exchangeable zinc pool.
• Zinc is primarily found in animal products and seafood.
• Similar to iron, zinc absorption is impaired by phytates, fiber, and
lignins, all of which impair the bioavailability from non-animal sources
of zinc.
• Calcium and casein may reduce the bioavailability of zinc from cow’s
milk.

27. Vitamin C
• General Good health
• Healthy gums and skin
• Delayed healing in deficiency states
• Scurvy on ship (Lind trial)
• Sources: citrus fruits

28. Strategies to reduce micronutrient
deficiencies in community
1. Food-based approaches (Medium / Long term
approach)
2. Food Fortification (Long term approach)
3. Bio-fortification (Long term approach)
4. Supplementation (Short term approach)

29. Examples of Food-Based Approaches
• Promotion Of exclusive breast feeding
• Promoting “kitchen gardens”
• Keeping poultry
• Use of diversified diet
• Improved nutrition of households

30. Solutions to hidden hunger
Diversifying diet
• Increasing dietary diversity ensures a healthy diet that
is balanced in combination of macronutrients
(carbohydrates, fats, and protein); essential
micronutrients; and other food-based substances such
as dietary fiber.
• A variety of cereals, legumes, fruits, vegetables, and
animal-source foods provide for nutrition for most
people, although certain populations, such as
pregnant women, may need supplements.
• Effective ways promoting dietary diversity involve
food-based strategies, such as home gardening and
educating people on better infant and young child
feeding practices, food preparation, and
storage/preservation methods to prevent nutrient
loss.

31. Solutions to hidden hunder
Fortifying Commercial Foods
• Adding trace amounts of micronutrients to staple foods
during processing
• Sustainable, and cost-effective public health strategy,
• Fortification has been particularly successful for iodized salt
• Adding B vitamins, iron, and/or zinc to wheat flour and
adding vitamin A to cooking oil and sugar.
• Fortification, however, has a number of shortcomings.
People may resist fortified foods.
• Fortificants, may not be stable and may be lost during
processing or storage.
• Bio-availability, the degree or rate at which a substance can
be absorbed, may be limited.

32. Other initiatives as solutions
• Behavior-change communication that aims to improve women’s,
infants’, and young children’s utilization of health services, clean
water, good sanitation, and hygiene to protect them from diseases
that interfere with nutrient absorption;
• Messaging that promotes best practices, such as early initiation of
exclusive breastfeeding up to 6 months followed by breastfeeding
up to 24 months with adequate and sufficient complementary food
as an economic and sustainable way to prevent hidden hunger in
children;
• Social protection that gives poor people access to nutritious food
and shields them from price spikes; and
• A focus on empowering women by increasing access to education.

33. Challenges
• Eliminating hidden hunger is not easy.
• Resources
• Policies developed,
• Right investments made, these challenges can be
overcome
• Much still needs to be done to ensure that
people around the world gain access to the
nutrient-rich foods they and their communities
need to combat poor health and reach their
development potential.

34. Solutions to hidden hunger: Biofortification
• Breeding food crops, using conventional or
transgenic methods, increases their micronutrient
content e.g. orange sweet potato, vitamin A maize,
vitamin A cassava, iron beans, iron pearl millet, zinc
rice, and zinc wheat.
• Not available in all developing countries, but is
expected to grow significantly in future
• Biofortification first targets rural areas then urban
ones.

35. Solutions to hidden hunger: Biofortification
Biofortified staple foods cannot deliver as high a level
nor as wide a range of minerals and vitamins as
supplements or industrially fortified foods can, they are
not the best response to clinical deficiencies. However,
they can help close the micronutrient intake gap and
increase the daily intake of vitamins and minerals
throughout a person’s life (iron beans, maize, pearl
millet, rice, sweet potato, and vitamin A cassava) show
evidence of improved micronutrient levels

36. Solutions to hidden hunger: Supplementation
• Vitamin A supplementation is a cost-effective interventions
for improving child survival. Funding, coverage varies
• Supplementation of other micronutrient deficiencies is less
common. Iron-folate supplements are prescribed to pregnant
women though coverage rates are often low and compliance
rates even lower.
• For children, home fortification with micro-nutrient powders
and lipid-based nutrient supplements can include multiple
micronutrients, like iron and zinc, but they are harder to get
into homes on a large scale than vitamin A supplements.
• The learning curve can be steep. In a trial in rural China, about
half of parents or grandparents stopped giving children
nutritional supplements containing soybeans, iron, zinc,
calcium, and vitamins because they suspected the free
supplements were unsafe or fake. They also feared they
would be charged later.

37. Multiple MNDs
• Lack of food security
• Disaster situations
• Lack of available quality and diversity of foods
• Poverty in certain population groups,
• Lack of access to health care and nutrition education,
• Subsistence farming practices,
• Volatile food prices,
• Urbanization,
• High rates of infection (both acute and chronic),
• Sanitation, climate change, and access to potable water

38. Micronutrient Deficiency (MND) questions
1. What are Micronutrients?
2. Define MND
3. What is the other name for MND?
4. What High Risk groups exist for MND?
5. What effects occur at national level when large sections of population are
suffering from MNDs?
6. What are the causes of MNDs?
7. MND can affect a lifespan?
8. What are common MNDs?
9. What are the strategies to combat MNDs?
10. What are the challenges in dealing with MND?
• Work in groups to identify research questions related to micronutrient deficiencies