This document provides an overview of electrolytes and discusses sodium and potassium in detail. It begins by listing the learning objectives which are to list the roles of six important electrolytes, name disorders of abnormal levels, identify the predominant extracellular anion, and describe aldosterone's role in water balance. It then discusses sodium and potassium individually, outlining their normal levels, functions, dietary sources, and related imbalances.

1. MODULE 3
Topic:
Electrolytes
Sub code: MLT504
Sub Name: Medical Lab Technician -1 (T)
Department: Department of MLT, SMAS
Faculty: A. Vamsi Kumar
Designation : Assistant professor

2. Course outcomes
• Provide technical information about test
results;

3. LEARNİNG OBJECTİVES
• At the end of this lecture, the student can be able to :
1. List the role of the six most important electrolytes in the body
2. Name the disorders associated with abnormally high and low
levels of the six electrolytes
3. Identify the predominant extracellular anion
4. Describe the role of aldosterone on the level of water in the
body

4. Contents
• Introduction to Electrolytes
• Electrolyte balance
• Homeostasis
• Imbalance disorders
• Acid –Base Balance
• conclusion

9. Metabolic
The metabolic definition is still popular with many biologists. It describes a
living system as an object with a definite boundary, continually exchanging
some of its materials with its surroundings, but without altering its general
properties, at least over some period of time. But
again there are exceptions. There are seeds and spores
that remain, so far as is known, perfectly dormant and
totally without metabolic activity at low temperatures for
hundreds, perhaps thousands, of years but that can revive
perfectly well upon being subjected to more clement
conditions. A flame, such as that of a candle in a closed
room, will have a perfectly defined shape with fixed
boundary and will be maintained by the combination of
its organic waxes with molecular oxygen, producing
carbon dioxide and water. A similar chemical reaction,
incidentally, is fundamental to most animal life on Earth.
Flames also have a well-known capacity for growth.

11. Biochemical
A biochemical or molecular biological definition sees
living organisms as systems that contain reproducible
hereditary information coded in nucleic acid molecules
and that metabolize by controlling the rate of chemical
reactions using proteinaceous catalysts known as
enzymes. In many respects, this is more satisfying than
the physiological or metabolic definitions of life. There
are, however, even here, the hints of counterexamples.
There seems to be some evidence that a virus-like agent
called scrapie contains no nucleic acids at all, although it
has been hypothesized that the nucleic acids of the host
animal may nevertheless be involved in the reproduction
of scrapie. Furthermore, a definition strictly in chemical
terms seems peculiarly vulnerable. It implies that, were a
person able to construct a system that had all the
functional properties of life, it would still not be alive if
it lacked the molecules that earthly biologists are fond
of--and made of.

12. Genetic
All organisms on Earth, from the simplest cell to man
himself, are machines of extraordinary powers,
effortlessly performing complex transformations of
organic molecules, exhibiting elaborate behavior
patterns, and indefinitely constructing from raw
materials in the environment more or less identical
copies of themselves. How could machines of such
staggering complexity and such stunning beauty ever
arise? The answer, for which today there is excellent
scientific evidence, was first discerned by the
evolutionist Charles Darwin in the years before the
publication in 1859 of his epoch-making work, the
Origin of Species. A modern rephrasing of his theory of
natural selection goes something like this: Hereditary
information is carried by large molecules known as
genes, composed of nucleic acids. Different genes are
responsible for the expression of different characteristics
of the organism.

13. During the reproduction of the organism
the genes also reproduce, or replicate, passing the
instructions for various characteristics on to the next
generation. Occasionally, there are imperfections, called
mutations, in gene replication. A mutation alters the
instructions for a particular characteristic or
characteristics. It also breeds true, in the sense that its
capability for determining a given characteristic of the
organism

14. This definition places great emphasis on the
importance of replication. Indeed, in any organism
enormous biological effort is directed toward replication,
although it confers no obvious benefit on the replicating
organism. Some organisms, many hybrids for example,
do not replicate at all. But their individual cells do. It is
also true that life defined in this way does not rule out
synthetic duplication. It should be possible to construct a
machine that is capable of producing identical copies of
itself from preformed building blocks littering the
landscape but that arranges its descendants in a slightly
different manner if there is a random change in its
instructions. Such a machine would, of course, replicate
its instructions as well.

15. But the fact that such a machine
would satisfy the genetic definition of life is not an
argument against such a definition; in fact, if the building
blocks were simple enough, such a machine would have
the capability of evolving into very complex systems that
would probably have all the other properties attributed to
living systems. The genetic definition has the additional
advantage of being expressed purely in functional terms:
it does not depend on any particular choice of constituent
molecules. The improbability of contemporary
organisms--dealt with more fully below--is so great that
these organisms could not possibly have arisen by purely
random processes and without historical continuity.
Fundamental to the genetic definition of life then is the
belief that a certain level of complexity cannot be
achieved without natural selection.

16. Thermodynamic
Thermodynamics distinguishes between open and closed
systems. A closed system is isolated from the rest of the
environment and exchanges neither light, heat, nor
matter with its surroundings. An open system is one in
which such exchanges do occur. The second law of
thermodynamics states that, in a closed system, no
processes can occur that increase the net order (or
decrease the net entropy) of the system (see
thermodynamics). Thus the universe taken as a whole is
steadily moving toward a state of complete randomness,
lacking any order, pattern, or beauty.

17. This fate has been known since the 19th century as the heat death of
the
universe. Yet living organisms are manifestly ordered
and at first sight seem to represent a contradiction to the
second law of thermodynamics. Living systems might
then be defined as localized regions where there is a
continuous increase in order. Living systems, however,
are not really in contradiction to the second law. They
increase their order at the expense of a larger decrease in
order of the universe outside. Living systems are not
closed but rather open. Most life on Earth, for example,
is dependent on the flow of sunlight, which is utilized by
plants to construct complex molecules from simpler
ones. But the order that results here on Earth is more
than compensated by the decrease in order on the sun,
through the thermonuclear processes responsible for the
sun's radiation.

18. Some scientists argue on grounds of quite general
open-system thermodynamics that the order of a system
increases as energy flows through it, and moreover that
this occurs through the development of cycles. A simple
biological cycle on the Earth is the carbon cycle. Carbon
from atmospheric carbon dioxide is incorporated by
plants and converted into carbohydrates through the
process of photosynthesis. These carbohydrates are
ultimately oxidized by both plants and animals to extract
useful energy locked in their chemical bonds. In the
oxidation of carbohydrates, carbon dioxide is returned to
the atmosphere, completing the cycle.

19. The existence of diverse definitions of life surely
means that life is something complicated. A fundamental
understanding of biological systems has existed since the
second half of the 19th century. But the number and
diversity of definitions suggest something else as well.
As detailed below, all the organisms on the Earth are
extremely closely related, despite superficial differences.
The fundamental ground pattern, both in form and in
matter, of all life on Earth is essentially identical. As will
emerge below, this identity probably implies that all
organisms on Earth are evolved from a single instance of
the origin of life.

31. Erwin Schrodinger

40. Intracellular Vs Extracellular
electrolytes

42. Normal Values of Electrolytes

43. Normal values of electrolytes

44. Functions of Electrolytes

58. 1. Sodium

63. 2. Potassium

64. Potassium

65. Dietary source of potassium

70. Minerals
• Minerals are essential for normal growth and
maintenance of the body.
• Major elements : Requirement >100 mg /day
Calcium Chloride
Magnesium Sulphur
Phosphorous Fluoride
Sodium
Potassium

71. Contd….
• Trace Elements : Requirement <100mg/day
Iron Zinc
Iodine Molybdenum
Copper Selenium
Manganese

72. Contd….
• Some are necessary for the body but their exact
functions are not known.
Ex.: Chromium, Nickel, Bromide, Lithium,
Barium
• Non-Essentials : seen in tissues. Contaminants in
food stuffs.
Ex.: Rubedium, Silver, Gold, Bismuth
• Toxic : should be avoided.
Ex.: Aluminium, Lead, Cadmium, Mercury

73. CALCIUM (Ca)
Total Calcium in human body: 1 – 1.5 Kg
In Bones – 99 %
In extra cellular fluid – 1 %
Sources :
- Milk (Cow’s Milk – 100mg/100ml)
- Egg, Fish, Vegetables - moderate
- Cereals (wheat, rice) - poor source

74. Plasma Calcium
Normal Plasma / Serum Calcium : 9 – 11 mg / dl
Ionized Calcium : 5 mg/dl
Protein bound Calcium : 4 – 5 mg/dl
Complexed with phosphate/citrate/ bicarbonate :
about 1 mg/dl

75. Daily Requirement
Adults : 500 mg/day
Children : 1200 mg/day
Pregnancy and Lactation : 1500 mg/day
>50 yrs. : 1500 mg/day
+20µg Vit.D
(to prevent osteoporosis)

76. Absorption
 1st and 2nd part of duodenum
 Against concentration gradient and requires
energy
 Requires carrier protein

77. Factors promoting Ca absorption
Vitamin – D (calcitriol)
synthesis of carrier protein calbindin – facilitates
absorption
Parathyroid Hormone – ↑ Ca transport from intestinal
cells
Acidity – favors Ca absorption
Amino acids – Lysine and Arginine

78. Factors Inhibiting Ca absorption
Phytates and oxalates - form insoluble calcium oxalates
High dietary phosphates - precipitate as calcium
phosphate
High pH - (alkaline)
High dietary fiber
Mal absorption syndrome - Fatty acids not absorbed and
form insoluble calcium salts of fatty acid

79. Functions
1. Bones & Teeth :
Formation of bone & teeth.
Bones are reservoir for Ca in the body.
Osteoblasts → bone deposition
Osteoclasts → demineralization.

80. 2. Muscle Contraction :
Ca mediates excitation & contraction of muscle
fibers.
Ca interacts with Troponin-C to trigger muscle
contraction.
Ca activates ATPase, ↑ interaction between
actin and myosin.

81. 3. Nerve Conduction :
Transmission of nerve impulses from pre-
synaptic to post-synaptic region.
4. Secretion of hormones :
Mediates the secretion of Insulin, PTH,
Calcitonin, Vasopressin etc.

82. 5. Second Messenger :
Ca & cyclic AMP are 2nd messengers of different
hormones. Eg: Glucogan
6. Membrane integrity & Permeability :
Influences transport of number of substances
across the membranous barrier.

83. 7. Blood Coagulation :
Factor IV in blood coagulation cascade.
prothrombin → Thrombin
8. Action on Heart :
Ca prolongs Systole.
↑ Ca concentration → ↑ myocardial
contractility

84. The Calcium-Binding Region of Prothrombin
Prothrombin binds calcium ions with the modified amino acid g-carboxyglutamate (red).

85. 9. Activation of Enzymes :
Calmodulin – Ca binding regulatory protein.
Binds with 4 Ca ions and leads to activation
of enzymes.

86. Homeostasis of Ca
The major factors that regulate the plasma
Calcium
• Calcitriol
• Parathyroid hormone
• Calcitonin

87. Calcitriol
• ↑ intestinal absorption of Ca.
• Stimulates Ca uptake by osteoblasts and
promotes Calcification.

88. P T H
Elevates serum Ca
• Demineralization of bone (Osteoclasts)
• Increases Ca reabsorption by renal tubules
• Increases intestinal absorption of Ca by
promoting synthesis of Calcitriol

89. Calcitonin
secreted by Para follicular cells of Thyroid gland
Lowers the serum Ca levels
• Calcification of bone (by osteoblasts)
• Increases the excretion of Ca into urine
Calcitonin & PTH are directly antagonistic

90. Calcitriol PTH Calcitonin
Blood calcium ↑ ↑ ↓
Main action Absorption
from gut
Deminerali-
zation
Oppose
demineraliza-
tion

92. Disorders of Calcium Metabolism
Hypercalcemia : > 11 mg/dl
causes:
 Hyperparathyroidism - Parathyroid adenoma
ectopic parathyroid
secreting tumor
 Multiple myeloma
 Paget’s disease
 Metastatic carcinoma of bone.

93. Hypocalcemia
TETANY
Ca < 8.5 mg/dl → mild tremors
< 7.5 mg/dl → typical Tetany
Causes :
Accidental removal of parathyroid glands
Autoimmune disease

94. Symptoms :
• Neuromuscular irritability
• Carpopedal spasms
• Laryngismus → stridor (noisy breathing)
laryngeal spasms may lead to death.
Signs : Chovstek’s sign +
Trousseau’s sign +
↑ Q-T interval in ECG

95. Chovstek’s sign
• A twitch of the facial
muscles following gentle
tapping over the facial
nerve in front of the ear
that indicates
hyperirritability of the
facial nerve

96. Trousseau’s sign
• A test for latent tetany in which carpal spasm is
induced by inflating a sphygmomanometer cuff
on the upper arm to a pressure exceeding
systolic blood pressure for 3 minutes.

97. Carpopedal spasm

101. IRON (Fe)MINERALS

102. INTRODUCTION
• Total body iron content : 3 - 5 gm
• Iron is present in almost all cells
• Heme containing proteins: Hb, myoglobin,
cytochromes, cytochrome oxidase, catalase,
peroxidase, xanthine oxidase & Trp pyrrolase

103. Contd….
• 75% of total Fe is in Hb & 5% in myoglobin
• Non-heme iron containing proteins : ferritin,
transferrin, hemosiderin, lactoferin (milk) &
neutrophils

104. BIOCHEMICAL FUNCTIONS
• Tissue Respiration :
Iron can change readily between Ferrous and
Ferric states and function in electron transfer
reactions.
Cytochromes
NADH dehydrogenase
Succinate dehydrogenase

105. Contd.…
• Transport of gases :
Able to bind with molecular O2 and CO2.
The main function is to coordinate the O2 molecule
into heme of hemoglobin, so that it can be
transported from the lungs to the tissues.

106. Contd….
• Oxidative Reactions :
Component of various oxidoreductase enzymes
-vital role in oxidative reactions.

107. Contd….
• Immune Response :
Required for effective activity of lysosomal
enzyme peroxidase – helps in phagocytic and
bactericidal activity of neutrophils.

108. Requirement
• Indian diet contain >10 – 20 mg of Iron.
only about 10% of it is absorbed.
• 1 mg is eliminated each day from human body
by shredding of skin epithelial cells & cells lining
urinary tract & small extent in urine + sweat.

109. Requirement is high in women
• 20-40 mg - blood loss in each menstrual
cycle.
• ↑ daily demand to 3-4 mg in pregnant &
lactating women.
• 900 mg – diversion of Iron to foetus in
pregnancy.
blood loss during delivery
subsequent breast feeding

110. Requirement
Children : 10 mg/day
Adults
Males : 10-12 mg/day
Women
Premenopausal : 18 mg/day
Postmenopausal : 10 mg / day
Pregnant & Lactating : 40 mg/day

111. Source
Good sources: Leafy vegetables (20mg/100g),
pulses (10mg/100g), cereals (5mg/100g), liver
(5mg/100g), meat (2mg/100g), fish, dried fruits,
jaggery and iron cookware
Poor sources: Milk (0.1 mg/100 ml), wheat,
polished rice

112. Absorption
• Ferric ions are reduced with the help of gastric
HCl, ascorbic acid, cys. and -SH groups of pro. ----
----- favors absorption.
• Ca, Cu, Zn, Pb ------------- inhibit absorption.
• Phytates (in cereals), oxalates (leafy veg) &
phosphates in the diet reduce absorption by
forming insoluble iron salts.
• Marginal ↓ by tea & eggs.

113. Regulation of Absorption
Mucosal block theory
• Absorbed by upper part of duodenum
• Homeostasis is maintained at the level of
absorption
–Iron stores depleted - absorption ↑
–Iron stores adequate - absorption ↓
• Only Fe++ (ferrous) form is absorbed
and not Fe+++ (ferric) form.

114. Contd….
• Ferrous Iron binds to mucosal cell protein called
Divalent Metal Transporter - 1 (DMT-1).
• This bound Iron is then transported into the
mucosal cell.
• Unabsorbed Iron is excreted.

115. Lumen of GIT Mucosal cells of GIT Plasma Tissues
Food Fe Apoferritin Apotransferrin
HCl
Organic acids Ferritin Transferrin
(Fe+++)
Fe+++ Fe+++ Ferro- Fe+++
Ascorbic acid reductase
Cysteine Ferroxidase Fe++ Ceruloplasmin
or Ferroxidase II
Fe++ Fe++ Fe++
Iron absorption and transport
Liver
Ferritin
hemosiderin
Bone marrow (Hb)
Muscle (Mb)
Other tissues

116. Inside the mucosal cell…..
• Iron oxidized to ferric state.
complexed with apoferritin to form Ferritin.
• Ferric Iron is released, reduced to Ferrous state
crosses the cell membrane.

117. Lumen of GIT Mucosal cells of GIT Plasma Tissues
Food Fe Apoferritin Apotransferrin
HCl
Organic acids Ferritin Transferrin
(Fe+++)
Fe+++ Fe+++ Ferro- Fe+++
Ascorbic acid reductase
Cysteine Ferroxidase Fe++ Ceruloplasmin
or Ferroxidase II
Fe++ Fe++ Fe++
Iron absorption and transport
Liver
Ferritin
hemosiderin
Bone marrow (Hb)
Muscle (Mb)
Other tissues

118. In the blood stream….
• Reoxidized to Ferric state by Ceruloplasmin
• Ferric Iron bound with Transferrin and
transported to tissues.

119. Lumen of GIT Mucosal cells of GIT Plasma Tissues
Food Fe Apoferritin Apotransferrin
HCl
Organic acids Ferritin Transferrin
(Fe+++)
Fe+++ Fe+++ Ferro- Fe+++
Ascorbic acid reductase
Cysteine Ferroxidase Fe++ Ceruloplasmin
or Ferroxidase II
Fe++ Fe++ Fe++
Iron absorption and transport
Liver
Ferritin
hemosiderin
Bone marrow (Hb)
Muscle (Mb)
Other tissues

120. Excretion
One-way element (very little of it is excreted)
Almost no iron is excreted through urine
Any type of bleeding will cause the loss
Normal level in plasma -------- 50 - 175 µg/dl

121. Deficiency
Iron deficiency anemia is the most common
nutritional deficiency diseases
Characterized by microcytic hypochromic
anemia (blood Hb <12 g/dl)

122. Iron deficiency anemia
Clinical Manifestations:
Anemia, Apathy
Achlorhydria
Impaired attention, Irritability, Lowered memory
Koilonychia (spoon nails)

123. Koilonychia

124. Causes of deficiency
 Hookworm infection
 Nephrosis
 Repeated pregnancy
 Lack of absorption
 Nutritional deficiency of Fe
 Chronic blood loss (piles, peptic ulcer, uterine
hemorrhage)

125. Toxicity
HEMOSIDEROSIS --------- uncommon
Occurs in persons receiving repeated blood
transfusion (in hemophilia, hemolytic anemia).
Common in Bantu tribe, because of staple diet,
corn, is low in phosphates, and their habit of
cooking foods in iron vessels.

126. It is manifested when total body iron is >25-30 gm,
where hemosiderin is deposited in almost all tissues.

128. Hemochromatosis
• Primary Hemochromatosis :
- genetic disorder – excessive storage of Iron
in tissues → tissue damage.
• Secondary Hemochromatosis :
- repeated blood transfusions
- excessive oral intake of Iron
eg. as in African Bantu tribes

129. Bronze diabetes
Deposition of iron
Liver cell death ------ cirrhosis
Pancreatic cell death -------- diabetes
Deposits under the skin cause yellow-brown
discoloration ---------- hemochromatosis
The triad of cirrhosis, diabetes and
hemochromatosis ------- bronze diabetes

131. PHOSPHOROUS

132. • The total body phosphate – 1 kg
80 % - Bone & Teeth
10 % - Muscles
• Mainly Intracellular ion – seen in all cells.

133. Functions
• Formation of bone & teeth
• Production of high energy phosphates:
ATP CTP GTP
creatine phosphate
• Synthesis of nucleoside co-enzymes:
NAD+ and NADP+
• DNA and RNA synthesis:
Phosho-diester linkages –backbone of structure

134. Contd….
• Formation of phosphate esters:
Glucose 6-phosphate, phospholipids
• Formation of phosphoprotein: Casein
• Activation of enzymes by phophorylation
• Phosphate buffer system of blood:
maintain the pH of blood at 7.4.

135. Requirement & Sources
• 500 mg/day
• Milk - good source
cereals
Nuts moderate source
Meat
• Calcitriol increases phosphate absorption

136. Serum levels
 Normal adults - 3 – 4 mg/dl
 Children - 5 – 6 mg/dl
 Whole blood phosphate – 40 mg/dl
 Decrease in phosphate levels:
Hyperparathyroidism
Rickets

137. SODIUM

138. • Chief cation of Extracellular fluid.
• Total body Sodium – 4000 mEq
50 % in bones
40 % in extracellular fluid
10 % in soft tissues

139. Biochemical Functions
• Sodium (as sodium bicarbonate) regulates
the body acid base balance.
• Sodium regulates ECF volume:
 Sodium pump is operating in all cells, so as
to keep Sodium extracellular.
 This mechanism is ATP dependent.

141. • Required for maintenance of osmotic
pressure and fluid balance.
• Necessary for normal muscle irritability and
cell permeability.

142. Daily requirement
• Normal diet contains 5 – 10 gm of sodium
mainly as sodium chloride
• Sources :
Common salt used in cooking medium
Bread whole grains
Nuts leafy vegetables
Eggs Milk

143. Absorption
• Readily absorbed in the GI tract.
very little < 2 % is found in faeces.
In Diarrhea – large quantities of sodium
is lost in faeces.

144. Excretion
• Kidney – major route of sodium excretion
• 800 gm/day of Na filtered in glomuruli
99 % - reabsorbed by proximal convoluted
tubule.
↑ reabsorption in distal tubules controlled
by aldosterone.

145. • In edema – water & sodium content of the
body increase.
• Diuretic drugs – excrete Na also along with
water.

146. Normal Values
• In plasma - 136 – 145 mEq/L
• In cells - 35 mEq/L
Mineralocorticoids influence Na metabolism
in adrenocortical insufficiency
↓ plasma Na
↑ urinary excretion of Na

147. Hypernatremia
• Cushing’s disease
• Prolonged cortisone therapy
• In dehydration – water predominantly lost
the blood volume decreased with
apparent ↑conc. of sodium

148. Hyponatremia
• Vomiting
• Diarrhea
• Burns
• Addison’s disease (adrenal insufficiency)
• In severe sweating, Na is lost considerably
- muscle cramps & headache.

149. Biochemical estimation
• Flame photometer
• Ion selective electrodes

150. POTASSIUM

151. • Principal intraracellular cation.
• Total body Potassium – 3500 mEq
75 % in skeletal muscle
• Required for regulation of acid base balance
and water balance in cells.
• Maintains intracellular osmotic pressure.
• Required for transmission of nerve impulse.

152. • Enzyme – Pyruvate kinase (of glycolysis) depend
on K+ for optimal activity.
• Adequate intracellular concentration of K+ is
necessary for proper biosynthesis of proteins by
ribosomes.
• Extracellular K+ influences cardiac muscle
activity.

153. Dietary requirement
• 3 – 4 g / day
• Sources :
Banana Potato
Orange Beans
Pineapple Chicken
Liver
Tender coconut water – rich source

154. Absorption & excretion
• Absorption: From GI tract – very efficient
(90%)
• In diarrhea – good proportion of K+ is lost in feces
• Excretion : Through urine
• Aldosterone ↑excretion of potassium.

155. Normal values
• In plasma : 3.4 – 5.0 mEq/L
• In whole blood : 50 mEq/L
Either high or low concentrations are
dangerous since K+ affects contractility of
cardiac muscle

156. Hypokalemia
• Over activity of Adrenal cortex (Cushing’s
syndrome)
• Prolonged cortisone therapy
• Prolonged diarrhea & vomiting
• Diuretics used for CCF may cause K+ excretion
S/S: irritability, muscular weakness, tachycardia,
cardiomegaly & cardiac arrest
ECG - flattened waves with T ↓

157. Hyperkalemia
• Renal failure
• Adrenocortical insufficiency (Addison’s disease)
• Diabetic coma
S/S : depression of CNS
mental confusion
numbness
bradycardia - cardiac arrest
ECG - T ↑

158. Fluorine (F)
Prevents dental caries
Increases hardness of bones and teeth
Sources: drinking water
Requirements
Children : 0.5-2.5 mg/day
Adults : 2.0-5.0 mg/day
Safe limit of fluoride : 1 ppm (parts per million)
1 ppm: 1 gm of F in million gm of water, which
is equal to 1 mg per 1000ml

159. Deficiency & Toxicity
Dental caries: < 0.5 ppm
Dental fluorosis: > 2 ppm
In children; mottling of enamel &
discoloration of teeth.
In adults; chronic intestinal upset, loss of
weight, loss of appetite & gastroenteritis
Skeletal fluorosis: >20 ppm; toxic
Osteoporosis & osteosclerosis, with brittle
bones

160. Contd.
Ligaments of spine & collagen of bones get
calcified
Genu valgum: advanced cases of skeletal
fluorosis (stiff joints)
Plasma: normal value : 4 µg/dl
fluorosis : 50 µg/dl

161. Iodine
• Total body iodine : 25-30 mg (80% in thyroid
gland)
Formation of thyroid hormones (T3 & T4)
Requirements:
Children : 40-120 µg/day
Adults : 100-150 µg/day
Pregnant women : 175 µg/day

162. Commercial source: seaweeds
Other sources: drinking water, vegetables, fruits,
iodized salt
Absorption: small intestine
only 30% of iodine in food is absorbed
Goiterogenous substances prevent absorption of
iodine
Eg: i, Cabbage & tapioca contain thiocyanate,
which inhibits iodine uptake by thyroid
ii, Mustard seed contains thiourea, which
inhibits iodination of thyroglobulin

163. Storage: iodothyroglobulin (glycoprotein)
Excretion: mainly through urine and also through
bile, saliva and skin
Plasma: 4-10 µg/dl
Deficiency:
Children : cretinism
Adults : goiter, hypothyroidism, myxedema

164. Zinc
Total body Zn: 2 gm (99% is intracellular)
60% in skeletal muscle
30% in bones
Prostate gland contains 100 µg/g & liver 50 µg/g
Sources: grains, beans, nuts, cheese, eggs, milk,
meat & shell fish

165. Absorption: duodenum
Cu, Ca, Cd, Fe & phytate interfere absorption.
Storage: in liver with a specific protein,
metallothionine.

166. Biochemical functions
 Cofactor for more than 300 enzymes eg:
carboxy peptidase, carbonic anhydrase, ALP, LDH,
ADH, superoxide dismutase & glutamate
dehydrogenase.
 Participate in the metabolism of carbohydrates,
lipids, proteins & nucleic acids.
 Required for transcription and translation.

167. Stabilizes insulin, when stored in β- cells of
pancreas.
Promotes the synthesis of retinol binding
protein.
Gusten, Zn containing protein in saliva, is
important for taste sensation.
Role in growth, reproduction & wound healing.

168. Requirement:
Children : 5-10 mg/day
Adults : 10-15 mg/day
Pregnancy & lactation: 15-20 mg/day
Deficiency:
• Hypogonadism
• Growth failure
• Impaired wound healing
• Decreased taste and smell acuity
Plasma : 50-150 µg/dl

169. COPPER (Cu)
MINERALS

170. Introduction
Total body Cu is 100 mg; quantitatively this is
next to iron and zinc
It is seen in muscles, liver, bone marrow, brain,
kidney, heart and hair
Cu containing enzymes:
Ceruloplasmin, cyt. oxidase, cyt. C, tyrosinase,
lysyl oxidase, ALA synthase, monoamine
oxidase, cytosolic superoxide dismutase, uricase
and phenol oxidase

171. Requirement & Sources
Infants & children : 1.5-3 mg/day
Adults : 2-3 mg/day
Sources:
• Cereals, meat, liver, kidney, egg yolk, nuts and
green leafy vegetables
• Milk is a poor source

172. Absorption
Mainly from duodenum and is mediated by a Cu
binding protein (metallothionein)
Only about 10% of dietary Cu is absorbed
Rate of absorption is reduced by phytates, Ca,
Fe, Zn and Mo in the intestines
Storage: liver & bone marrow
Transport: albumin

173. Excretion: bile
Urine doesn't contain Cu in normal
circumstances
Plasma copper: 100-200 µg/dl
 95% is tightly bound to ceruloplasmin
 Small fraction (5%) is loosely held to histidine
residues of albumin
 Normal serum conc. of ceruloplasmin: 25-50
mg/dl

174. Deficiency
microcytic normochromic anemia
Fragility of arteries, deminiralization of bones,
demyelination of neural tissue, myocardial fibrosis,
hypopigmentation of skin, greying of hair
Minke’s kinky hair syndrome: results from
defective cross linking of connective tissue due to
Cu deficiency

175. Wilson’s hepatolenticular degeneration
Rare (1 in 50,000)
Cu deposition
Liver : hepatic cirrhosis
Brain (lenticular nucleus): brain necrosis
Kidney : renal damage
Chronic toxicity may lead to diarrhea and blue-
green discoloration of saliva.

176. Selenium (Se)
Least abundant and most toxic of essential
elements
Sources
Plants (varies with soil content), meat, sea foods
Requirements
Children : 10-30 µg/day
Adult male : 40-70 µg/day
female : 45-55 µg/day
Pregnancy & lactation: 65-75 µg/day

177. Biochemical functions
Acts as a nonspecific intracellular antioxidant by
providing protection against peroxidation in
tissues and cell membranes.
Complementary to vit. E; availability of vit. E
reduces the Se requirement.
Glutathione peroxidase protects the cells
against the damage caused by H2O2
.
Protects from developing liver cirrhosis.
Conversion of T4 to T3 by 5´- deiodinase.

178. Plasma Se
Normal value : 13 µg/dl
Most of the Se in blood is a part of
glutathoine reductase.
Inside the cells, it exists as selenocysteine and
selenomethionine.
Absorption: duodenum
Se is carcinogenic in animals, its oncogenic
influence in man is not established.

179. Deficiency
Marginal deficiency; when soil content is low.
In animals; hepatic necrosis, retarded growth,
muscular degeneration, infertility.
In humans; congestive cardiomyopathy
(Keshan disease) in China.
Toxicity: selenosis ( 900 µg/day)
Hair loss, dermatitis, irritability, purple streaks
in nails, falling of nails, diarrhea and garlicky
odor in breath (dimethyl selenide).