Journal of Diabetes, Metabolic Disorders & Control
Impact of zinc on thyroid metabolism
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is essential for normal functioning of metabolic homeostasis, immune
system, cell stimulation, enzyme activity, protection against oxidative
stress, and neural transmission.4,5 It works as co-enzyme factor for
many enzymes which are involved in various metabolic processes
and it is essential for sensitizing the tissues to thyroid hormone.6 Zinc
is also involved in cell differentiation, proliferation, cell repairing
and renewal. The importance of zinc in endocrine system is that it
effect on growth, endocrine homeostasis, and thyroid function and on
glucose metabolism.7 Deciency of zinc in the body may result in
decreased levels of secretion of thyroid hormones which affects the
normal metabolism of the body and resting metabolic rate. Some of
the studies shown that deciency of zinc is associated with enhanced
the expression of hepatic thyroxine-5’-monodeiodinase enzyme
activity which catalyses the thyroid hormone inactivation.8,9
Hypothyroidism and zinc
Zinc is essential trace element for normal levels of thyroid
hormones such as triiodothyronine (T3), tetraiodothyronine (T4), and
thyroid stimulating hormone (TSH) (Table 1). Some of the studies
showed that zinc deciency leads decrease in T3 level. The well known
effect of zinc on some endocrine glands such as pituitary- a master
gland and on hypothalamus is that it appears a role in the synthesis
of releasing hormone such as thyrotrophic releasing hormone (TRH).
Some of the studies showed that in hypothyroidism alteration in zinc
level. Patients with thyroid cancer have signicantly low level s of
zinc.10–12 In Hypothyroidism metabolic rate gets reduce which results
in adverse effect on organ system (Table 2).13 Hypothyroidism can
lead to number of complications in humans such as:
a) Mental health issues such as depression and also cause the slow
functioning of brain.
b) Heart problems because of increase in the level of Low density
lipoprotein (LDL) cholesterol. Sometimes it causes heart failure
and enlarges heart.
c) In hypothyroidism the low levels of thyroid hormone can alter the
process of ovulation which leads to infertility in women.
Hyperthyroidism and zinc
Consumption of high amount of zinc can contribute to
hyperthyroidism or Graves’ disease because zinc acts as a stimulator
to the thyroid gland. Patients suffering from hyperthyroidism have
higher amount of urinary excretion of zinc.14 Over activity of thyroid
gland or some other causes leads to hyperthyroidism (Table 3). When
tissues are exposed to higher concentrations of thyroid hormones then
some physiological, clinical and biochemical alterations occur in the
body (Table 4). Many studies shown that hyperthyroidism affects
many organ systems.15 Some of the researchers reported that zinc
is a fundamental component of enzymatic antioxidant system with
several antioxidant properties. Zinc is required in the body for optimal
activity of many hormones like thyroid hormone.16,17
Table 1 Causes of Hypothyroidism
Autoimmune disease Radiation Therapy
Thyroid surgery Treatment for hyperthyroidism
Iodine deciency Pituitary disorder
Table 2 Symptoms of Hypothyroidism
Elevated blood cholesterol
Muscle weakness, Muscle aches
Slowed heart rate Depression
Excessive sleepiness Constipation
Irregular menstrual periods Weight gain
Thinning of hair Dry skin and puffy face
Table 3 Causes of Hyperthyroidism
Excessive intake of iodine Hyperfunctioining of thyroid
Thyroid cancer Alteration in the secretion of TSH
Inammation in the thyroid
gland Grave’s disease
Postpartum thyroiditis Toxic thyroid adenoma
J Diabetes Metab Disord Control. 2018;5(1): 00134
Volume 5 Issue 1 - 2018
Department of Biological Sciences, Yobe State University, Nigeria
Correspondence: Sabina Khanam, Department of Biological
Sciences, Yobe State University, Damaturu, Nigeria, Email
Received: October 22, 2017 | Published: February 26, 2018
Thyroid gland is the most important endocrine gland in human
body which performs various functions. Thyroid hormones such
as thyroxin and triiodothyronine are essential various metabolic
functions and also required for normal functions of body tissues.
These thyroid hormones affect metabolic rate and consumption on
oxygen.1 The most important constituent of thyroid hormones is
iodine. The geographical areas where the amount of iodine is less
thyroid dysfunction and diseases are very common. Thyroid disease
is the commonest endocrine disorder in the whole world. Thyroid
diseases are caused due to over secretion and under secretion of
thyroid hormones. These diseases are more common in females.2,3
Zinc is essential trace element for human body in limited amount. It
Citation: Khanam S. Impact of zinc on thyroid metabolism. J Diabetes Metab Disord Control. 2018;5(1): 00134. DOI: 10.15406/jdmdc.2018.05.00134
Impact of zinc on thyroid metabolism 28
Table 4 Symptoms of Hyperthyroidism
Fast and Irregular heartbeat Vomiting , Nausea
Difculty in sleeping Weight loss
Increased appetite Dizziness and shortness of breath
Brittle hair and hair loss Development of breast in men
Congestive heart failure Protruding eyes
Fertility problems Paralysis
Increased sweating Light menstrual periods
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