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Introduction
to iron and serum ferritin tests
Iron is fundamentally required by the body to form adequate numbers
of normal red blood cells. These are the cells that carry oxygen
throughout the body. The key protein in red blood cells to which
oxygen attaches is called hemoglobin (haemoglobin in Europe). Hemoglobin
is a very iron rich biochemical. Iron is also needed by other cells,
especially muscle cells which contain another oxygen binding protein
called myoglobin. Typically in the healthy individual, about 65%
of the iron in the body is in hemoglobin (in red blood cells) and
about 4% in myoglobin (in skeletal muscle). About 30% of the iron
in the body is stored (as ferritin or hemosiderin) in liver, bone
marrow, and the spleen. A small percentage of the body's iron is
in transport between various compartments of the body (in association
with transferrin) or is a component of enzymes in cells throughout
the body. Free iron is very reactive (it stimulates free radical
reactions) and is not normally in body fluids. Low iron levels can
lead to anemia, in which the body cannot produce enough red blood
cells. This results in a poor ability to transfer oxygen around
the body and the symptoms are chronic lethargy (tiredness) and a
very pale skin pallor. So for the body in general, iron is very
important.
However, there is a lot of argument among professionals as to whether
iron is important for hair growth. Some say it is vital and that
deficiencies in serum iron and ferritin, the biochemical state in
which iron is stored in the body, can have a dramatically negative
impact on hair growth. The predominant belief among most general
practitioners is that iron deficiency should not be a significant
cause of hair loss. Some dermatologists agree. However, there are
now several scientific studies and a growing number of dermatologists
claiming that iron deficiency is relatively common. Even with a
Western diet it is suggested that chronic iron deficiency is common
and can lead to a gradual development of diffuse hair loss - a kind
of telogen effluvium. It is believed that as people have reduced
their rate of red meat intake, a rich source of iron, and switched
to white meats or vegetarianism, so iron deficiency has become more
common.
Iron
and serum ferritin test result normal ranges table
| Factor tested |
Normal range for
test value |
| |
Adult men |
Adult women |
| Serum Iron (micro grams per deciliter) |
60 - 160 µg/dL |
60 - 160 µg/dL |
| Total Iron Binding Capacity (TIBC) (micrograms
per deciliter) |
240 to 450 µg/dL |
240 to 450 µg/dL |
| Serum Ferritin (micro grams per liter) |
20-300 µg/L (official value
stated by non-dermatologists)
OR
70-300 µg/L (claimed by dermatologists who believe
iron deficiency causes hair loss)
|
18-200 µg/L (official value stated by non-dermatologists)
OR
70-200 µg/L (claimed by dermatologists who believe
iron deficiency causes hair loss)
|
| Hemoglobin (grams per deciliter) |
13.0 –18.0 g/dL |
12.0 - 16.0 g/dL |
| Mean Corpuscular Hemoglobin (MCH) (pico grams
per cell) |
27 - 35 pg/cell |
27 - 35 pg/cell |
| Mean Corpuscular Hemoglobin Concentration (MCHC)
(grams per deciliter) |
32 - 37 g/dL |
32 - 37 g/dL |
| Mean Corpuscular Volume (MCV) (cubic micrometers)
|
78 - 100 cu µm |
78 - 102 cu µm |
| Red Blood Cell Count (RBC) (millions per microliter) |
4.2 - 6.9 million/µL (normal
range varies with age) |
4.2 - 6.9 million/µL (normal
range varies with age) |
| Transferrin (milligrams per deciliter) |
191 –365 mg/dL |
191 –365 mg/dL |
| Transferrin saturation (percentage) |
20-50% |
20-50% |
An
explanation of iron and serum ferritin tests
There are actually several aspects of the iron metabolic pathway
that can be tested. In terms of hair loss the most useful test value
is believed to be the serum ferritin level. However, testing other
iron parameters can be helpful in understanding the general health
of patients.
Serum iron level - Serum iron is a measure of circulating
iron bound to transferrin and reflects total body iron. Serum iron
measurements may be affected by menstrual cycle, time of day, diet,
hepatitis, and use of iron containing placebos found in some oral
contraceptive packages. On its own this test just gives a snap shot
in time of your iron levels and it is not very helpful for defining
a chronic iron deficiency or other iron problems. However, when
the test value is examined in comparison to other iron tests it
can help provide information leading to a disease diagnosis.
Serum ferritin level - Ferritin is an indicator of stored
iron in the body. Ferritin is the main protein that stores iron
for areas that need it, especially the liver and the bone marrow
where red blood cells are made. The iron ferritin level is the first
in line to drop if the individual suffers any iron insufficiency
from diet, malabsorption or loss during heavy or menstruation lasting
more than 5 days. A drop in the iron ferritin level occurs before
any depletion in serum iron (as seen in iron-deficient anemia) and
may decrease significantly without any obvious symptoms whatsoever.
While the serum ferritin level at which a deficiency can be claimed
is hotly argued by different schools of doctors, an excess of serum
ferritin is generally agreed to be a bad thing. Iron stored at high
levels is toxic. The body can only metabolize so much iron in a
day. If it receives too much, the body is overwhelmed and toxic
effects develop. It is possible to overdose on iron supplements.
For this reason, taking large supplement doses of iron is not recommended.
If, in response to a low iron and ferritin test result, you start
to take iron supplements and feel ill, it probably means you are
taking to much for your body to cope with. Take a lower dose.
Total Iron Binding Capacity (TIBC) - TIBC measures the
amount of transferrin you have. Transferrin is a blood protein that
transports iron from the gut, where the iron is absorbed from food,
to the cells that use it. When iron stores are low, the body will
make more transferrin so that it can collect more iron absorbed
from food and make more efficient use of it. If there is too much
iron coming from the gut, the body will reduce production of transferrin
so that less of the iron is taken up and transported around the
body. On average about one third of the transferrin in the body
is being used to transport iron. Because of this, the blood serum
of healthy individuals has an excess iron-binding capacity. This
is called the Unsaturated Iron Biding Capacity (UIBC). The TIBC
equals UIBC plus the serum iron measurement. Some laboratories measure
UIBC, some measure TIBC, and some measure transferrin. These tests
are usually done together and analyzed in relation to each other.
On their own the values do not mean much, but together the test
results are helpful in defining several iron problems.
Hemoglobin and Hematocrit – Hemoglobin and hematocrit
levels are tested when anemia is suspected. Serum hemoglobin is
a test that measures the level of free (outside red blood cells)
hemoglobin in the blood while hematocrit is the measurement of the
percentage of red blood cells in whole blood. It is an important
determinant of anemia (decreased), dehydration (elevated) or possible
overhydration (decreased). These tests can be useful for understanding
iron metabolism in the body as one cause of anemia is iron deficiency.
These tests are usually conducted in conjunction with a complete
blood cell count (CBC) looking at numbers of while blood cells (see
the blood cell count test page in this section). Of these other
test values the Mean (average) Corpuscular Volume (MCV) can also
indirectly help understand iron metabolism as MCV measures how big
the red blood cells are. Corpuscule is just a fancy word for cell.
When a deficiency in iron occurs, not enough hemoglobin is made.
This leads to a somewhat reduced rate of red blood cell production
and the red blood cells are often smaller than normal (microcytic)
and paler than normal (hypochromic).
An
explanation of what iron and serum ferritin test results mean for
hair loss
Iron, UIBC, TIBC and ferritin test results are often looked at
from the global perspective. A change in one test value exerts an
influence on one or more of the other test values. Depending on
how these different test values deviate from the norm and each other,
an iron problem can be diagnosed. Classic iron deficiency due to
a lack of iron intake results in a test result pattern where the
serum iron level and serum ferritin level is low while the TIBC
and UIBC levels are high. If this is observed, and the claim that
iron deficiency causes telogen effluvium hair loss is believed,
then iron supplements or an iron rich diet may help.
Other test result patterns can suggest other problems that may
affect hair growth in a different way. If the serum iron and TIBC
levels are low While UIBC is low to normal and ferritin levels are
normal to high, the pattern is consistent with a chronic illness.
Chronic illness may itself cause hair loss through a general reduction
in nutrients and sometimes hormonal stimulation for hair follicles.
A diffuse telogen effluvium hair loss can be the result.
Telogen effluvium can also develop after exposure to toxins and
iron in excessive amounts is toxic. A test result pattern where
the serum iron and and ferritin levels are excessively high, but
the TIBC and UIBC are low suggests an excessive intake of iron.
There is also a genetic condition called hemochromatosis where the
affected individual cannot process iron properly and even with low
iron intake the iron can build up in the body to toxic levels. In
affected individuals the pattern of iron tests results show a high
serum iron level, but normal levels for ferritin and TIBC and low
to normal levels for UIBC. Where hemochromatosis is suspected and
genetic test should be conducted to if the individual carries a
certain gene mutation (below).
Testing
for hemochromatosis
Hemochromatosis is relatively common in Northern Europe and descendants
of Europeans in the Americas. It has an official expression frequency
at approximately 6 in 100,000 people although some doctors believe
the condition is under diagnosed and the frequency of expression
could be as high as 1 in 200. It is caused by a mutation in a gene
called "HFE". The most common mutation is called C282Y
but there are other rarer mutations as well. The HFE gene regulates
the amount of iron absorbed from the gut. In people who have two
copies of an abnormal form of the gene, the protein made by the
gene cannot tell the cells in the gut when the body is “full”
of iron, so the gut keeps on absorbing iron and excess iron damages
many different organs. If a blood iron test suggests hemochromatosis
may be a problem then another blood sample may be drawn and subjected
to the HFE gene test. People with hemochromatosis may suffer from
chronic telogen effluvium - although there are usually other associated
clinical symptoms of iron poisoning.
In February 1997, a panel of medical experts convened by the CDC
recommended that transferrin saturation (TS) be used as the initial
diagnostic test for hereditary hemochromatosis. A value above 50%
indicates a potential hemochromatosis diagnosis and further tests
should be done.
Iron
and serum ferritin tests references
- Jacobs P, Wood L. Hematology of malnutrition,
part one. Dis Mon. 2003 Oct;49(10):555-618.
- Chorney MJ, Yoshida Y, Meyer PN, Yoshida
M, Gerhard GS. The enigmatic role of the hemochromatosis protein
(HFE) in iron absorption. Trends Mol Med. 2003 Mar;9(3):118-25.
- Neff LM. Current directions in hemochromatosis
research: towards an understanding of the role of iron overload
and the HFE gene mutations in the development of clinical disease.
Nutr Rev. 2003 Jan;61(1):38-42.
- Borgaonkar MR. Hemochromatosis. More common
than you think. Can Fam Physician. 2003 Jan;49:36-43.
- Sinclair R. There is no clear association
between low serum ferritin and chronic diffuse telogen hair loss.
Br J Dermatol. 2002 Nov;147(5):982-4.
- Rushton DH. Nutritional factors and hair
loss. Clin Exp Dermatol. 2002 Jul;27(5):396-404.
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tissue iron status have a role in female alopecia? J Eur Acad
Dermatol Venereol. 1999 Jul;13(1):65-7.
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in women. Clin Dermatol. 1997 Jan-Feb;15(1):113-25.
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J Dermatol. 1994 Feb;130(2):261-3.
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capacity in iron poisoning. Is it useful? Am J Dis Child. 1991
Apr;145(4):437-9.
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B. Clinical utility of serum tests for iron deficiency in hospitalized
patients. Am J Clin Pathol. 1990 Feb;93(2):240-5.
- Rushton DH, Ramsay ID, James KC, Norris
MJ, Gilkes JJ. Biochemical and trichological characterization
of diffuse alopecia in women. Br J Dermatol. 1990 Aug;123(2):187-97.
- Pootrakul P, Josephson B, Huebers HA, Finch
CA. Quantitation of ferritin iron in plasma, an explanation for
non-transferrin iron. Blood. 1988 Apr;71(4):1120-3.
- Cazzola M, Pootrakul P, Bergamaschi G,
Huebers HA, Eng M, Finch CA. Adequacy of iron supply for erythropoiesis:
in vivo observations in humans. J Lab Clin Med. 1987 Dec;110(6):734-9.
- Finch CA, Huebers HA. Iron metabolism.
Clin Physiol Biochem. 1986;4(1):5-10.
- Mussalo-Rauhamaa H, Lakomaa EL, Kianto
U, Lehto J. Element concentrations in serum, erythrocytes, hair
and urine of alopecia patients. Acta Derm Venereol. 1986;66(2):103-9.
- [No authors listed]. Non-anemic iron deficiency
as an etiologic factor in diffuse loss of hair of the scalp in
women. Acta Derm Venereol. 1963;43:562-9.
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