NOTA SLAID

Functions

• DNA synthesis and cell division

• as coenzymes in single-carbon
transfer in the metabolism of
nucleic and amino acids.

• The DNA and methylation cycles
both regenerate tetrahydrofolate
(THF, one form of folate)

• Maturation of red blood cells and other cells
• Involvement in basic cell reproduction and growth makes folate

essential for healthy embryonic development

• Good folate status in early pregnancy reduces the risk of birth defects

(in an embryo) a hollow structure from
which the brain and spinal cord form

Sources

• Largest amount and most bioavailable folate

• liver, legumes and leafy green vegetables

• Other rich sources of folate

• legume, avocados, asparagus, broccoli, wheat germ, citrus fruits (especially
strawberries and oranges), fortified bread and cereal products.

• Extremely vulnerable to heat, UV and oxygen
• Cooking and other food-processing and preparation techniques can

destroy 50 – 90% of folate in food.
• Vitamin C in foods helps protect folate from oxidation

RNI for Malaysia (2017)

Age group 0 – 5 months µg/day
Infant 6 – 11 months 80
80
Children 1 – 3 years 160
4 – 6 years 200
≥10 years 7 – 9 years 300
Pregnancy 400
Lactation 600
500

Dietary Folate Equivalents (DFE)

RDA for folate is expressed as DFE DFE- A measure of folate intake
Synthetic folate from supplement and used to account for the high
fortified foods is absorbed at almost 1.7X
the rate of naturally occurring folate from bioavailability of folic acid taken as
other foods a supplement compared with the
Body absorbs nearly 100% of folic acid in lower bioavailability of the folate
supplements and fortified foods
found in foods.

The relationship between DFE, food folate and folic acid is as follows:
1 DFE=

1 µg food folate=
0.6 µg folic acid taken with food=
0.5 µg folic acid taken on an empty stomach

100 μg folate from a serving of cooked spinach =
100 μg DFE

100 μg folic acid from a serving of fortified ready-
to-eat cereal = 170 μg DFE

100 μg supplemental folic acid taken without food
= 200 μg DFE

How to estimate DFE?

A pregnant woman eats a bowl of fortified corn flakes, and two slices of fortified
bread.

Item Folate/folic acid Note
Fortified corn flakes 100 µg folic acid
1 μg folic acid as a fortificant
Fortified bread 40 µg folic acid = 1.7 μg DFE

The diet also contains 90 µg of food folate 1 μg folic acid as a fortificant
= 1.7 μg DFE

1 μg DFE =1.0 μg food folate

DFE= µg food folate + (1.7 x µg synthetic folate)
= 90 µg + (1.7 x 140 µg) = 90 + 238 = 328 µg

Why?

• Bioavailability of synthetic folate close to 100 %
• Bioavailability of natural folate is affected by the removal of the

polyglutamate chain by the intestinal conjugase

• This process is apparently not complete
• Thereby reducing the bioavailability of natural folate by as much as 25-30 %

Toxicity

• Excessive intake of folic acid has been associated with increased
cancer risk such as colorectal cancer

• Excess intake of fortified food or supplements

• mask a B12 deficiency

Tolerable upper intake level

Deficiency

• Interferes with normal red blood cell division

• Megaloblasts → macrocytes → macrocytic anemia
• RBCs abnormally large

• Macrocytic anemia

• Fatigue
• Weakness
• Irritability
• Shortness of breath

• Neural tube defects

• Heart disease: high homocysteine
• Neuropsychiatric disorders
• Affects cell types that are actively synthesizing DNA

Cobalamin (B12)

• Unlike other B vitamins:

• the only vitamin that contains a mineral (cobalt) as part of its structure
• Foods of animal origin

• B12 is the most chemically complex of all the vitamins
• Closely related to folate

2 Forms - Both contain Cobalt

Functions

• Folate metabolism

• B12 is required to convert folate coenzymes to the active forms needed for
reactions such as DNA synthesis

• Therefore, B12 deficiency can result in symptoms of folate deficiency



• Maintaining myelin sheaths that insulate nerve fibers from each other

• People with B12 deficiencies have destruction of segments of the myelin
sheaths

• Paralysis, death

• Vit B12-dependent enzymes
also work with THF to
convert homosysteine to
methionine

• thereby reducing
homocysteine blood levels and
lowering the risk of heart
disease

Sources

• All vitamin B12 compounds are synthesize by microorganisms, mainly
bacteria

• Sources: meat, poultry, seafood, eggs, milk and dairy products

• Rich sources: Organ meats (liver, kidneys and heart) and fortified
foods (ready to eat cereals)

RNI for Malaysia (2017)

Age group 0 – 5 months µg/day
Infant 6 – 11 months 1.2
1.5
Children 1 – 6 years 1.5
7 – 9 years 2.5
Adolescent 10 – 12 years 3.5
>12 years 4.0
Pregnancy 4.5
Lactation 5.0

Toxicity

• No tolerable upper intake has been set
• No adverse effects have been observed with excess vitamin B12

intake from food or from supplement

Deficiency

• Pernicious anemia

• Results from an auto immune
disorder in which the body destroys
the parietal cells in the stomach

• Loss of parietal cells means a loss of
intrinsic factor → reduces B12
absorption

• The resulting deficiency can lead to pernicious anemia and its associated
nerve generation.

• Symptoms: weakness, sore tongue, back pain, apathy and tingling in the
extremities

• Pernicious means leading to death

• Elevated plasma homocysteine concentrations

• Poor B12, folate and B6 status can each result in high levels of the amino acid
homocysteine  risk factor for heart attack and strokes

Vitamin C

• Comes in 2 interchangeable biologically active forms:

• Ascorbic acid
• Dehydroascorbic acid

• Synthesized by most animals (not by humans)



Functions

• Collagen Synthesis

• Vitamin C plays an important role in the formation of collagen
• It is the most abundant protein in our bodies
• Collagen fibers are

• important constituents of connective tissues, such as tendons and ligaments, bone,
blood vessels, eyes and skin

• Essential in wound healing

• Antioxidant activity

• Vitamin C loses electrons easily, which allows it to perform as an antioxidant
• Protects cells from free radicals
• In the body, antioxidants defend against free radicals, minimizes free radical

damage cells

Sources

• Mostly occur in foods of plant origins
• Many fruits and vegetables are high in vitamin C (tomatoes, broccoli,

cabbage, spinach, peppers, lettuce, leafy greens, citrus fruits,
strawberries, guava, fortified juice drinks).

• Animal products and grains are generally not good sources
• Among animal-based foods, only liver or kidney can be considered

significant sources
• Easily destroyed by heat and oxygen
• The least stable vitamin- easily lost in storage, processing and cooking

RNI for Malaysia (2017)

Age group 0 – 5 months mg/day
Infant 6 – 11 months 25
30
Children 1 – 6 years 30
7 – 9 years 35
Adolescent 10 – 18 years 65
>18 years 70
Pregnancy 80
Lactation 95

Toxicity

• Upper level for adults : 2 g per day (based on adverse gastrointestinal
effects)

• Symptoms:

• Nausea
• Abdominal cramps
• Diarrhea
• Headache
• Gastrointestinal discomfort

Tolerable Upper Intake Levels

Deficiency

• Deficiency disease is called scurvy

• Fatigue and then formation of spots on the skin, spongy gums, and bleeding
from mucous membranes.

• Person feels depressed, pale and partially immobilized.
• Advanced scurvy shows open suppurating (pus filled) wounds, loss of teeth,

yellow skin, fever, neuropathy and finally death from bleeding.

• A deficiency of vitamin C prevents the normal synthesis of collagen

• causing significant changes in connective tissue throughout the body.

• As the loses its ability to synthesize collagen:

• Connective tissue starts breaking down and gums and joints begin to bleed
• Weakness develops and small haemorrhages appear around the hair follicles,

on the arms and legs



Spots on Skin Follicular Hemorrhages

• As the disease progresses:

• Previously healed wounds reopen, bone pain, fractures, diarrhea and
physiological problems such as depression

8.0
MINERALS

DR. ARNIDA HANI TEH

Carbohydrate

Protein MACRONUTRIENTS
Fat Body needs in larger amounts

Produce energy

Macrominerals • potassium, calcium, magnesium, sodium,
chloride, sulfur, phosphorus.

Microminerals • chromium, cobalt, copper, fluorine, iodine, MICRONUTRIENTS
iron, manganese, molybdenum, selenium, zinc Body needs in

smaller amounts

Vitamins • Fat soluble (A,D,E,K)
• Water soluble (B,C)

Included in RNI (2017)

• Macro minerals:

• Calcium, phosphorus, sodium, potassium and magnesium

• Micro minerals / trace elements:

• iron, iodine, zinc, selenium, chromium, copper, manganese, molybdenum and
fluoride

8.1
Macro minerals

Calcium (Ca)

• Calcium is the fifth most abundant element in the human body,

• with approximately 1000 g present in adults (99% in the skeleton)

• An essential element that is only available to the body through
dietary sources.

Functions

• One of the most important functions is to provide a “structural role”
in providing rigidity (structure and strength) to the skeleton

• In bone, calcium serves two main purposes:

• provides skeletal strength
• provides a dynamic store to maintain the calcium pools

Sources

• Dairy products, cereals
• Fish with edible bones such as canned sardines and anchovies
• Beans and bean products including yellow dhal, tofu and tempeh

(fermented soybeans),
• Locally processed foods such as shrimp paste, cincaluk and budu,
• Vegetables like spinach, watercress, mustard leaves, cekur manis, tapioca

leaves, kai-lan and broccoli