Trace metals are metals in extremely small
quantities that are present in animal and
plant cells and tissue. They are a necessary
part of nutrition and physiology. Ingestion
of, or exposure to, excess quantities is often
toxic. However, insufficient plasma or tissue
levels of certain trace metals can cause
pathology as well; as is the case with iron.
Trace metals include
iron, magnesium, lithium, zinc, copper, chromium, nickel, cobalt, vanadium, ar
senic, molybdenum, manganese, selenium and others.
Trace metals are depleted through the expenditure of energy by various
metabolic processes living organisms. They are replenished in animals
through diet as well as environmental exposure, and in plants through the
uptake of nutrients from the soil in which the plant grows.
Some metals are naturally found in the body and are necessary for proper
human health. Iron can help to prevent anemia, and zinc is a cofactor in over
100 enzyme reactions. All though trace metals are good for humans, in high
doses they may be toxic to the body.
Essential trace elements are required by man in amounts ranging from 50
micrograms to 18 milligrams per day. Acting as catalytic or structural
components of larger molecules, they have specific functions and are
indispensable for life. Research during the past quarter of a century has
identified as essential six trace elements whose functions were previously
unknown. In addition to the long-known deficiencies of iron and iodine, signs
of deficiency for chromium, copper, zinc, and selenium have been identified
in free-living populations. Four trace elements were proved to be essential for
two or more animal species during the past decade alone. Marginal or severe
trace element imbalances can be considered risk factors for several diseases
of public health importance, but proof of cause and effect relationships will
depend on a more complete understanding of basic mechanisms of action
and on better analytical procedures and functional tests to determine
marginal trace element status in man.
Role of Iron in the Body
Iron is an essential element for most life on Earth,
including human beings.
Iron is needed for a number of highly complex
processes that continuously take place on a
molecular level and that are indispensable to
human life, e.g. the transportation of oxygen
around your body!
Iron is required for the production of red blood cells (a process known as
haematopoiesis), but it's also part of haemoglobin (that is the pigment of the
red blood cells) binding to the oxygen and thus facilitating its transport from
the lungs via the arteries to all cells throughout the body.
Once the oxygen is delivered the iron (as part of haemoglobin) binds the
carbon dioxide which is then transported back to the lung from where it gets
Iron is also involved in the conversion of blood sugar to energy. Metabolic
energy is crucial for athletes since it allows muscles to work at their optimum
during exercise or when competing
The production of enzymes (which play a vital role in the production of new
cells, amino acids, hormones and neurotransmitters) also depends on
iron, this aspect becomes crucial during the recovery process from illnesses or
following strenuous exercise or competing.
The immune system is dependent
on iron for its efficient functioning
and physical and mental growth
require sufficient iron
levels, particularly important in
childhood and pregnancy, where
the developing baby solely
depends on its mother's iron
Iron is lost by the body through a variety of ways including
urination, defecation, sweating, and exfoliating of old skin cells.
Bleeding contributes to further loss of iron which is why women
have a higher demand for iron than men.
If iron stores are low, normal haemoglobin production slows
down, which means the transport of oxygen is diminished,
resulting in symptoms such as fatigue, dizziness, lowered
immunity or reduced ability for athletes to keep up with their
Since our bodies can’t produce iron itself, we need to make sure
we consume sufficient amounts of iron as part of our daily diet.
Spatone, natural liquid iron supplement can provide your body’s
daily absorbed iron needs whilst being extra gentle on the
Iron deficiency (sideropenia or hypoferremia) is one of the most common of the
nutritional deficiencies. Iron is present in all cells in the human body, and has
several vital functions. Examples include as a carrier of oxygen to the tissues
from the lungs in the form of hemoglobin, as a transport medium for electrons
within the cells in the form of cytochromes, and as an integral part of enzyme
reactions in various tissues. Too little iron can interfere with these vital
functions and lead to morbidity and death.
The eventual consequence of iron deficiency is iron deficiency
anemia where the body's stores of iron have been depleted and
the body is unable to maintain levels of haemoglobin in the
blood. Children and pre-menopausal women are the groups
most prone to the disease.
Total body iron averages approximately 3.8 g in men and 2.3 g in
women. In blood plasma, iron is carried tightly bound to the
protein transferrin. There are several mechanisms that control
human iron metabolism and safeguard against iron deficiency.
The main regulatory mechanism is situated in the
gastrointestinal tract. When loss of iron is not sufficiently
compensated by adequate intake of iron from the diet, a state of
iron deficiency develops over time. When this state is
uncorrected, it leads to iron deficiency anemia.
Symptoms of iron deficiency can occur even before the condition has
progressed to iron deficiency anemia.
Symptoms of iron deficiency are not unique to iron deficiency (i.e. not
pathognomonic). Iron is needed for many enzymes to function normally, so a
wide range of symptoms may eventually emerge, either as the secondary
result of the anemia, or as other primary results of iron deficiency. Symptoms
of iron deficiency include:
brittle or grooved nails
chronic bleeding (haemoglobin contains iron)
excessive menstrual bleeding
bleeding from the gastrointestinal tract (ulcers, hemorrhoids, Ulcerative
Colitis gastric or colonic carcinoma etc.)
rarely, laryngological bleeding or from the respiratory tract
substances (in diet or drugs) interfering with iron absorption
inflammation where it is adaptive to limit bacterial growth in infection, but is
also present in many other chronic diseases such as Inflammatory bowel
disease and rheumatoid arthritis
Though genetic defects causing iron deficiency have been studied in
rodents, there are no known genetic disorders of human iron metabolism
that directly cause iron deficiency.
Possible reasons that athletics may contribute to lower iron levels includes
mechanical hemolysis (destruction of red blood cells from physical
impact), loss of iron through sweat and urine, gastrointestinal blood loss, and
haematuria (presence of blood in urine). Although small amounts of
iron are excreted in sweat and urine, these losses can generally be seen as
insignificant even with increased sweat and urine production, especially
considering that athlete’s bodies appear to become conditioned to retain iron
better. Mechanical hemolysis is most likely to occur in high impact
sports, especially among long distance runners who experience “foot-strike
hemolysis” from the repeated impact of their feet with the ground. Exercise-
induced gastrointestinal bleeding is most likely to occur in endurance
athletes. Haematuria in athletes is most likely to occur in those that undergo
repetitive impacts on the body, particularly affecting the feet (such as running
on a hard road or Kendo) and hands (e.g.Conga or Candombe drumming).
Additionally, athletes in sports that emphasize weight loss
(ballet, gymnastics, marathon running, wrestling) as well as sports that
emphasize high-carbohydrate, low-fat diets, may be at an increased risk for
A complete blood count can reveal microcytic anemia, although this is not always
present - even when iron deficiency progresses to iron deficiency anaemia.
Low serum ferritin *see below
Low serum iron
High TIBC (total iron binding capacity), although this can be raised in cases of anaemia
of chronic inflammation
It is possible that the fecal occult blood test might be positive, if iron deficiency is the
result of gastrointestinal bleeding, although the sensitivity of the test may mean that
in some cases it will be negative even with enteral blood loss
As always, laboratory values have to be interpreted with the lab's reference values in
mind and considering all aspects of the individual clinical situation.
Serum ferritin can be elevated in inflammatory conditions and so a normal serum
ferritin may not always exclude iron deficiency, and the utility is improved by taking a
concurrent C reactive protein (CRP). The level of serum ferritin that is viewed as "high"
depends on condition. For example, in Inflammatory bowel disease the threshold is
100, where as in chronic heart failure (CHF) the levels are 200.
Before commencing treatment, there should be definitive diagnosis of the underlying
cause for iron deficiency. This is particularly the case in older patients, who are most
susceptible to colorectal cancer and the gastrointestinal bleeding it often causes. In
adults, 60% of patients with iron deficiency anemia may have underlying
gastrointestinal disorders leading to chronic blood loss. It is likely that the cause of
the iron deficiency will need treatment as well.
Upon diagnosis, the condition can be treated with iron supplements. The choice of
supplement will depend upon both the severity of the condition, the required speed
of improvement (e.g. if awaiting elective surgery) and the likelihood of treatment
being effective (e.g. if has underlying IBD, undergoing dialysis or is having ESA
Examples of oral iron that are often used are ferrous sulfate, ferrous gluconate, or
amino acid chelate tablets. Recent research suggests the replacement dose of iron, at
least in the elderly with iron deficiency, may be as little as 15 mg per day of elemental
Mild iron deficiency can be prevented or corrected by eating iron-rich foods and by
cooking in an iron skillet. Because iron is a requirement for most plants and animals, a
wide range of foods provide iron. Good sources of dietary iron have heme-iron as this
is most easily absorbed and is not inhibited by medication or other dietary
components. Three examples are red meat, poultry and insects
Non-heme sources do contain iron, though it has reduced bioavailability. Examples are
lentils, beans, leafy vegetables, pistachios, tofu, fortified bread, and fortified breakfast
Iron from different foods is absorbed and processed differently by the body; for
instance, iron in meat (heme iron source) is more easily absorbed than iron in grains
and vegetables ("non-heme" iron source)
but heme/hemoglobin from red meat has effects which may increase the likelihood of
colorectal cancer.Minerals and chemicals in one type of food may also inhibit
absorption of iron from another type of food eaten at the same time.
For example, oxalates and phytic acid form insoluble complexes which bind iron in the
gut before it can be absorbed.
Because iron from plant sources is less easily absorbed than the heme-bound
iron of animal sources, vegetarians and vegans should have a somewhat
higher total daily iron intake than those who eat meat, fish or poultry.
Legumes and dark-green leafy vegetables like broccoli, kale and oriental
greens are especially good sources of iron for vegetarians and vegans.
However, spinach and Swiss chard contain oxalates which bind iron making it
almost entirely unavailable for absorption. Iron from nonheme sources is
more readily absorbed if consumed with foods that contain either heme-
bound iron or vitamin C. This is due to a hypothesised "meat factor" which
enhances iron absorption.
Many medicinal herbs can offer iron boosting properties to those who suffer
from iron deficiency. These medicinal properties can easily be assimilated into
the bloodstream as a hot water infusion (tea). Iron enhancing herbs include
yellow dock, red raspberry
leaf, gentian, yellowroot, turmeric, mullein, nettle, parsley, ginseng, watercres
s, and dandelion.
Following are two tables showing the richest foods in heme and non-heme
iron. In both tables, foods serving size may differ from the usual 100g
quantity for relevancy reasons. Arbitrarily, the guideline is set to 18 mg, which
is the USDA Recommended Dietary Allowance for women aged between 19
Iron deficiency can have serious
health consequences that diet may
not be able to quickly correct,
hence an iron supplement is often
necessary if the iron deficiency has
Bioavailability and bacterial
Iron is needed for bacterial growth making its bioavailability
an important factor in controlling infection. Blood
plasma as a result carries iron tightly bound to
transferrin, which is taken up by cells by endocytosing
transferring, thus preventing its access to bacteria.Between
15 and 20 percent of the protein content in human milk
consists of lactoferrinthat binds iron. As a comparison, in
cow's milk, this is only 2 percent. As a result, breast fed
babies have fewer infections.Lactoferrin is also concentrated
in tears, saliva and at wounds to bind iron to limit bacterial
growth. Egg white contains 12% conalbumin to withhold it
from bacteria that get through the egg shell (for this reason
prior to antibiotics, egg white was used to treat infections)
To reduce bacterial growth, plasma concentrations of iron are lowered in a
variety of systemic inflammatory states due to increased production of
hepcidin which is mainly released by the liver in response to increased
production of pro-inflammatory cytokines such as Interleukin-6. This
functional iron deficiency will resolve once the source of inflammation is
rectified, however if not resolved it can progress to Anaemia of Chronic
Inflammation. The underlying inflammation can be caused by fever,
Inflammatory Bowel Disease, infections, Chronic Heart Failure
(CHF), carcinomas and following surgery.
Reflecting this link between iron bioavailability and bacterial growth, the
taking of oral iron supplements causes a relative over abundance of iron that
can alter the types of bacteria that are present within the gut. There have
been concerns regarding parenteral iron being administered whilst
bacteremia is present, although this has not been borne out in clinical
practice. A moderate iron deficiency, in contrast, can provide protection
against acute infection, especially against organisms that reside within
hepatocytes and macrophages such as Malaria and TB. This is mainly
beneficial in regions with a high prevalence of these diseases and where
standard treatment is unavailable.