Magnesium acts as a co-factor More than 300 enzymes requires magnesium as a cofactor Magnesium is an allosteric activators of many enzyme systems It is essential for peptidases, ribonucleases, glycolytic enzymes & co-carboxylation reactions Magnesium influences the secretion of PTH by the parathyroid glands & hypomagnesaemia may cause hypoparathyriodism
1 – M.Sc (N&D)
Iodine is mainly used to make thyroid hormones.
The thyroid helps to regulate the rate at which your
body uses energy. It also plays a role in growth and
You only need very small amounts of iodine for good
health. Without iodine your health can be affected over
the long term.
Your body does not make iodine so it needs to come
from the foods you eat.
The iodine content in foods can vary. The mineral
content of foods depends on the mineral content of the
soil where the food was grown or where the animals
What is iodine?
• Iodine is a mineral that is
important for health. It is needed
to make the thyroid hormones.
These hormones are needed for
many body processes including
growth, regulating metabolism
and for the development of a
baby’s brain during pregnancy
and early life.
DISTRIBUTION IN THE HUMAN BODY
• The total body contains about 20 mg of
• 80% is present in the thyroid gland.
• Muscles, salivary glands & ovaries also
contain some amount of iodine.
• Iodine is absorbed from upper small intestine.
• Iodine is transported in plasma by loosely binding
to plasma proteins.
• Iodine absorption also occurs through skin & lungs.
• 80% of body’s iodine is stored in the organic form
as iodothyroglobulin in thyroid gland
• Iodothyroglobulin contains thyroxine,
diiodotyrosine, & triiodothyronine.
• About 2/3rd of iodine is excreted through urine.
• Also excreted through bile, skin & saliva.
Elevates pH (Iodine is an alkalinizing agent)
Necessary for the production of thyroid hormones
Necessary for the production of all the hormones of the
body (adrenals, ovaries, testicles, etc.)
Responsible for the formation of the normal architecture
of the glandular tissue, e.g. breast, thyroid, ovary, &
Green peas, cooked
Bread (rye, whole wheat, white)
The best natural occurring source of iodine is saltwater seafood.
Freshwater seafood also contains iodine.
• Children require about 50 µg per day.
• Adults 100 – 150 µg per day.
• Pregnant Women 200 µg per day.
A deficiency of iodine in children leads to cretinism and in adults goitre.
Abnormal increase in size of the
thyroid gland is known as goiter.
Decreased synthesis of thyroid
hormones & is associated with
Goiter is primarily due to a failure
in the auto regulation of T3 & T4
Simple endemic goiter
• Due to iodine deficiency in the diet.
• Mostly found in the geographical regions, where the water & soil
are low in iodine.
• Consumption of iodized salt is advocated to overcome the
problem of endemic goiter.
• In certain cases, administration of thyroid hormone is also
• Hypothyroidism in children is associated with physical & mental
retardation, known as critinism.
Iodine deficiency prophylaxis:
• Iodised salt
• Iodised oil
• Iodised water
• Iodine tablets or drops
• Most people are very tolerant to excess iodine intake from food
with the exception of certain subgroups with autoimmune
thyroid disease and iodine deficiency.
• High intakes of iodine from food, water and supplements have
been associated with thyroiditus, goitre (due to increased thyroid
stimulating hormones [TSH] stimulation),hypothyroidism,
hyperthyroidism, sensitivity reactions, thyroid papillary cancer
and acute responses in some individuals.
• Symptoms of acute iodine poisoning include burning
of the mouth, throat, and stomach, abdominal pain,
fever, nausea, vomiting, diarrhoea, weak pulse, cardiac
irritability, coma and cyanosis
• It is mainly found in bones & teeth.
• The content of fluorine in water is
dependent on the soil content of fluorine.
1-2 mg/ day
Drinking water provides fluoride 1 ppm.
Ingested in excessive quantities, fluoride can be toxic. The
American Dental Association has recommended that no
more than 120 mg fluoride.
Common signs and symptoms of acute fluoride toxicity
include nausea, vomiting, and a drop in blood calcium,
general signs of muscle tetany. Signs also include
abdominal cramping and pain and increasing hypo
calcaemiaand hyperkalemia, leading coma, convulsions,
and cardiac arrhythmias.
DISTRIBUTION IN THE HUMAN BODY
• 50 % of the absorbed fluoride will be associated with calcified tissue
• 50% excreted in urine
• 75 to 90 % absorbed from the alimentary tract, more from liquids
than solids (10 to 25% excreted via feces)
50:50 distribution is shifted strongly in favor of retention
in the very young, greater excretion in later years of life
• Unnoticeable, tiny white streaks or specks in
the enamel of the tooth.
Mild Dental Flourosis
Tooth appearance is marred by discoloration
or brown markings.
Pitted Enamel, Rough and Hard to Clean.
Sever Dental Flourosis
Strengthening of developing teeth from infancy to
Strengthens teeth by the formation of harder
enamel by converting HYDROXYAPATITE
CRYSTALS to FLUORAPATITE.
Flourapatite is less vulnerable to damage from
• Magnesium is essential for human life and is involved in the
activation of hundreds of enzyme systems. However, only relatively
recently has it been recognized as a drug with important clinical
uses; the World Health Organization (WHO) recommends the use
of magnesium in the management of pre-eclampsia and eclampsia,
it is used in the management of tetanus and increasingly for the
management of tachyarrhythmias. This tutorial discusses the role of
magnesium in the body, disorders of magnesium and its clinical
• Magnesium exerts an effect on neuromuscular irritability similar to that of Ca2+,
high levels depress nerve conduction & low levels may produce tetany
• About 70% of body magnesium is present as apatites in bones, dental enamel
• Insulin-dependent uptake of glucose is reduced in Mg2+ deficiency, magnesium
supplementation improves glucose tolerance
• Magnesium is required for DNA replication process.
• The human body contains about 25g of magnesium
• About 60% of which is complexed with calcium and
phosphorous in bones
• About 1% is in ECF and remainder in soft tissues
• Magnesium is widely distributed in vegetables &
also found in almost all animal tissues
• Other important sources are cereals, beans, green
vegetables, potatoes, almonds, and dairy products,
• Adult man : 350 mg/day
• Women : 300 mg/day
• During pregnancy and lactation : 450 mg/day
• Increase in serum magnesium than the normal levels is called as
• It is uncommon but is occasionally seen in renal failure
• It is rarely be caused by intravenous injection of magnesium salts and
• Depression of the neuromuscular system is the most common manifestation in
• Decrease in serum magnesium levels than the normal range is called as
• Magnesium is present in most common food stuffs, low dietary intakes of
magnesium are associated with nutritional insufficiency, accompanied by
intestinal malabsorption, severe vomiting, diarrhea or other causes of intestinal
• Symptoms are impaired neuromuscular function, tetany, hyper irritability, tremor,
convulsions and muscle weakness