NOTA SLAID

Calcium Density

• Learn to appreciate calcium-dense food

Food Calcium Energy Calcium density
(mg) (kcal) (mg/kcal)
Sardines, 3 oz 325 176
canned 325 mg ÷ 176 kcal =
1.85 mg/kcal

RNI (2017)

Deficiencies

• Reduced mineralization of bone
• Reduced bone mass and osteoporosis

Tolerable upper intake levels

Toxicity

• The common effects of excessive calcium intakes are

• kidney stones (nephrolithiasis),
• milk-alkali syndrome and
• interaction of calcium with absorption of other essential minerals

• such as iron, zinc, magnesium and phosphorous.

Phosphorus (P)

• Phosphorus comprises approximately 1% of total body weight

Functions

• The main function: in the formation of bones and teeth
• It plays an important role in how the body uses carbohydrates and

fats, and protein
• Helps the body make ATP

• a molecule the body uses to store energy

• Phosphorus also helps to maintain normal acid-base balance

• by acting as buffers

Sources

• Rich food sources of phosphorus include cheese, meat, fish, poultry
and nuts.

• Meanwhile, there is only small amount in plants.

RNI (2017)

Deficiency

• Rare
• But possible if consume drugs known as
• phosphate binders
• In elderly possible due to poor food intake
• Symptoms

• muscular, neural, skeletal, renal & other abnormalities

Tolerable upper intake levels

Toxicity

• Hyperphosphatemia can cause

• Calcification (accumulation of calcium salt) of non-skeletal tissues

• most commonly kidneys

• Such calcium phosphate deposition can lead to organ damage

• especially kidney damage

Sodium (Na)

• Sodium is found in most foods as sodium chloride (NaCl), generally
known as ‘salt’

• 1 teaspoon or 5 g salt provides 2000 mg sodium

Functions

• Principle electrolyte in the extracellular fluid

• Primary regulator of

• extracellular fluid volume
• plasma volume
• blood pressure

• Aids in nerve impulse conduction

• Aids in regulating muscle control NERVE FIBER
(contraction)

• Aids in nutrient absorption including
glucose

MUSCLE FIBER

Sodium channels open, allowing a huge flow of positively
charged sodium ions to enter the muscle fiber

• Maintains acid-base balance by combining
with an anion such as:

+ chloride to form + bicarbonate to
sodium chloride form sodium
bicarbonate

These act as buffers to absorbed hydrogen ions to
help maintain a normal cellular and blood pH

Sources

• Major source is salt

• Protein food generally contain more natural sodium than vegetables and
grains

• milk, meat and shellfish

• Often found in high amounts in processed foods

• such as breads, crackers, processed meats and snacks foods.

• High amounts of sodium are also found in many condiments (e.g soy and
fish sauces)

• Fruits contain little or no sodium

RNI (2017)

AI = adequate intake

Deficiency

• Sodium deficiency

• rare
• with diarrhea, vomiting, heavy sweating

• Hyponatremia

• occurs when sodium is lost excessively due to diarrhea, vomit & perspiration

• Normally lost of sodium is related to lost of water

Tolerable Upper Intake Levels

Toxicity

• Toxicity and excess intake lead to:

• edema and hypertension

Potassium (K)

• Major cation in intracellular fluid.

Functions

• Build proteins
• Break down and use carbohydrates
• Promotes cellular growth

• Maintain normal body growth

• Regulation of nerve and muscle function
• Control the electrical activity of the heart

• Steady heartbeat

• Control the acid-base balance

Sources

• Many foods contain potassium
• Fruits, vegetables, fresh meat and dairy products are good sources
• Fruits that contain significant sources of potassium include

• citrus fruits, cantaloupe, bananas, kiwi, prunes, and apricots

RNI (2017)

Deficiency

• Hypokalemia

a small fine pulse, feeling
like a small cord or thread
under thefinger

blockage of the intestines

Hypokalemia can occur due to:

Consuming diuretics

• for the treatment of high blood pressure or heart failure

Consuming too many laxatives
Severe or prolonged vomiting and diarrhea
Certain kidney or adrenal gland disorders

Tolerable upper intake level

• In a generally healthy population with normal kidney function, a
potassium intake from foods above the RNI poses no potential for
increased risk

• because excess potassium is readily excreted in the urine.

• Therefore, a Tolerable Upper Intake Level (UL) was not set.

Toxicity

• Hyperkalemia

Some common causes include:

Poor kidney function

Heart medicines

• angiotensin converting enzyme (ACE) inhibitors and angiotensin
2 receptor blockers (ARBs)

Potassium-sparing diuretics

• diuretic drugs that do not promote the secretion of potassium
into the urine such as spironolactone

Severe infection

Magnesium (Mg)

• An adult body contains approximately 25 g magnesium,

• with 50% to 60% present in the bones and
• most of the rest in soft tissues

Modes by which Mg2+ provides stability to ATP

Functions

• To stabilize the structure of ATP

• As ATP utilization is involved in many metabolic
pathways, magnesium is essential in the intermediary
metabolism for

• the synthesis of carbohydrates, lipids, nucleic acids and
proteins

• specific actions in various organs such as the neuromuscular
or cardiovascular system.

• Cofactor for enzymes

• in ATP-dependent enzyme reactions

• E.g., in glycolysis: hexokinase, glucokinase, phospho-fructokinase

• Magnesium has an impact on bone health

• through its role in the structure of hydroxyapatite crystals in bone.

Sources

• Most dietary magnesium comes from vegetables, such as dark green,
leafy vegetables

• Other foods that are good sources of magnesium:

• Fruits such as banana, avocado
• Nuts such as almonds and cashews

RNI (2017)

Deficiency

• Rare

• Hypomagnesemia could occur due to:

• Gastrointestinal disorders
• Renal disorders (magnesium wasting)
• Chronic alcoholism
• Age

• Early signs of magnesium deficiency include

• loss of appetite, nausea, vomiting, fatigue and weakness

Tolerable upper intake levels

Toxicity

• Hypermagnesemia
• Could occur due to:

• advanced chronic kidney disease
• excessive intake of magnesium salts or magnesium-containing drugs
• particularly in elderly

• Associated with hypotension, cutaneous flushing, nausea and
vomiting

8.2
Micro minerals

Iron (Fe)

Functions

• Iron containing heme proteins such as haemoglobin, myoglobin and
cytochromes

• which is important for oxygen transport and storage as well as electron transport.

• Iron sulphur enzymes

• involved primarily in energy metabolism

• Iron storage and transport proteins

• participating in iron uptake, transport and storage in the body such as
transferrin, lactoferrin, ferritin and hemosiderin.

• Other iron-containing or activated enzymes such as sulphur and
nonheme enzymes.

• Iron also plays important roles in cellular processes

• such as the synthesis of DNA, RNA and proteins

Sources

• Two types of iron in foods

• Haem iron

• derived primarily from the haemoglobin and myoglobin of flesh foods such as meats,
fish, and poultry

• Non-haem iron

• found in plant foods such as breads, cereals, dark leafy vegetables (such as spinach,
kangkung), legumes and eggs

RNI (2017) • Bioavailability
15%, 10%:
depending on diet
composition.

• 15% for diversified
diets with
generous amounts
of meat and/or
foods rich in
ascorbic acid.

• 10% is for diets
based on cereals,
tubers and
legumes with little
or no meat or
ascorbic acid-
containing fruits
and vegetables

Deficiency

• Clinical features of iron deficiency include

• koilonychia (spoon-shaped nails), soft nails, glossitis, cheilitis (dermatitis at
the corner of the mouth), mood changes, muscle weakness and impaired
immunity.

• However, these features are not specific to iron deficiency but may also be
manifestation of other nutritional deficiencies.

• Iron deficiency anaemia

• Impaired physical work performance, developmental delay, cognitive
impairment, and adverse pregnancy outcomes

Tolerable upper intake levels

Toxicity

• Hemosiderosis

• due to consumption of abnormally large
amount of iron or

• in those with genetic defect

• resulting in excessive iron absorption

• iron overload resulting in the accumulation of

hemosiderin Image of a kidney viewed under a microscope.
The brown areas contain hemosiderin

• Hemochromatosis

• hereditary disorder
• iron salts are deposited in the tissues
• leading to liver damage, diabetes mellitus, and

bronze discoloration of the skin