latent iron deficiency

• complete blood count{{Cite web|url=http://www.merckmanuals.com/professional/hematology-and-oncology/anemias-caused-by-deficient-erythropoiesis/iron-deficiency-anemia|title=Iron Deficiency Anemia|website=Merck Manuals Professional Edition|access-date=2016-06-22}}
• hemoglobin{{Cite web|url=http://www.mayoclinic.org/diseases-conditions/iron-deficiency-anemia/basics/definition/con-20019327|title=Iron deficiency anemia - Mayo Clinic|website=www.mayoclinic.org|access-date=2016-06-22}}
• serum iron
• total iron binding capacity
• serum ferritin
• bone marrow examination (rarely)

Note: Iron therapy must be suspended 48 hours beforehand to ensure valid test results.

The normal range for hemoglobin is 13.8 to 17.2 grams per deciliter (g/dL) for men and 12.1 to 15.1 g/dL for women.{{Cite web|url=https://www.nlm.nih.gov/medlineplus/ency/article/003645.htm|title=Hemoglobin: MedlinePlus Medical Encyclopedia|website=www.nlm.nih.gov|access-date=2016-06-22}} Low hemoglobin indicates anemia but the individual will be normal for LID.

Normal serum iron is between 60 and 170 micrograms per dL (μg/dL).{{Cite web|url=https://www.nlm.nih.gov/medlineplus/ency/article/003488.htm|title=Serum iron test: MedlinePlus Medical Encyclopedia|website=www.nlm.nih.gov|access-date=2016-06-22}} Normal total iron-binding capacity for both sexes is 240 to 450 μg/dL. Total iron-binding capacity increases when iron deficiency exists.

Serum ferritin levels reflect the iron stores available in the body. The normal range is 20 to 200 nanograms per milliliter (ng/mL) for men and 15 to 150 ng/mL for women.{{Cite web|url=https://www.nlm.nih.gov/medlineplus/ency/article/003490.htm|title=Ferritin blood test: MedlinePlus Medical Encyclopedia|website=www.nlm.nih.gov|access-date=2016-06-22}} Low levels (< 12 ng/mL) are specific for iron deficiency. However, inflammatory and neoplastic disorders can cause ferritin levels to increase – this may be seen in cases of hepatitis, leukemia, Hodgkin lymphoma, and gastrointestinal (GI) tract tumors.

The most sensitive and specific criterion for iron-deficient erythropoiesis is depleted iron stores in the bone marrow. However, in practice, a bone marrow examination is rarely needed.

LID is present in Stages 1 and 2, before anemia occurs in Stage 3. These first two Stages can be interpreted as depletion of iron stores and reduction of effective iron transport.

Stage 1 – Characterized by loss of iron stores in the bone marrow while hemoglobin and serum iron levels remain normal. Serum ferritin falls to less than 20 ng/mL. Increased iron absorption, a compensatory change, results in an increased amount of transferrin and consequently increased iron-binding capacity.

Stage 2 – Erythropoiesis is impaired. In spite of an increased level of transferrin, serum iron level is decreased along with transferrin saturation. Erythropoiesis impairment begins when the serum iron level falls to less than 50 μg/dL and transferrin saturation is less than 16%.

Stage 3 – Anemia (reduced hemoglobin levels) is present but red blood cell appearance remains normal.

Stage 4 – Changes in the appearance of red blood cells are the hallmark of this stage; first microcytosis and then hypochromia develop.

Stage 5 – Iron deficiency begins to affect tissues, manifesting as symptoms and signs.

There is no consensus on how to treat LID but one option is to treat it as iron-deficiency anemia by giving the individual ferrous sulfate (Iron(II) sulfate) at a dose of 100 mg per day in two doses (one at breakfast and the other at dinner){{cite journal |title=Iron absorption studies in iron deficiency |journal=Scandinavian Journal of Haematology. Supplementum |volume=20 |pages=1–125 |year=1974 |pmid=4526330|last1=Norrby |first1=A }}https://pmc.ncbi.nlm.nih.gov/articles/PMC1272837/ or 3 mg per kilogram (kg) per day in children (also in two doses){{cite journal |title=Iron deficiency in infancy and childhood |journal=The American Journal of Clinical Nutrition |volume=33 |issue=1 |pages=86–118 |date=January 1980 |pmid=6986756 |url=http://www.ajcn.org/cgi/pmidlookup?view=long&pmid=6986756|last1=Dallman |first1=P. R. |last2=Siimes |first2=M. A. |last3=Stekel |first3=A |doi=10.1093/ajcn/33.1.86 |doi-access=free }} for 2 or 3 months. The ideal is to increase the body's iron deposits, measured as levels of ferritin in serum, with the aim of reaching a ferritin value between 30 and 100 ng/mL. A clinical study has shown an increase in ferritin levels in those taking iron compared with others receiving a placebo.{{cite journal|last2=Chalmers|first2=K. A.|last3=Collins|first3=C. E.|last4=Patterson|first4=A. J.|date=April 2014|title=Comparison of two doses of elemental iron in the treatment of latent iron deficiency: efficacy, side effects and blinding capabilities|journal=Nutrients|volume=6|issue=4|pages=1394–405|doi=10.3390/nu6041394|pmc=4011041|pmid=24714351|last1=Leonard|first1=A. J.|doi-access=free }} With ferritin levels higher than 100 ng/mL, an increase in infections has been reported.{{cite journal |title=Anemia of chronic disease |journal=The New England Journal of Medicine |volume=352 |issue=10 |pages=1011–23 |date=March 2005 |pmid=15758012 |doi=10.1056/NEJMra041809|last1=Weiss |first1=G |last2=Goodnough |first2=L. T. }} Another way to treat LID is with an iron-rich diet with ascorbic acid or vitamin C, contained in many types of fruits such as oranges, kiwifruits, etc., which will increase iron absorption 2- to 5-fold.{{cite journal |title=Iron absorption from rice meals cooked with fortified salt containing ferrous sulphate and ascorbic acid |journal=The British Journal of Nutrition |volume=31 |issue=3 |pages=367–75 |date=May 1974 |pmid=4835790 |doi=10.1079/BJN19740045|last1=Sayers |first1=M. H. |last2=Lynch |first2=S. R. |last3=Charlton |first3=R. W. |last4=Bothwell |first4=T. H. |last5=Walker |first5=R. B. |last6=Mayet |first6=F |doi-access=free }}{{cite journal |title=The fortification of common salt with ascorbic acid and iron |journal=British Journal of Haematology |volume=28 |issue=4 |pages=483–95 |date=December 1974 |pmid=4455301|last1=Sayers |first1=M. H. |last2=Lynch |first2=S. R. |last3=Charlton |first3=R. W. |last4=Bothwell |first4=T. H. |last5=Walker |first5=R. B. |last6=Mayet |first6=P |doi=10.1111/j.1365-2141.1974.tb06667.x|s2cid=5516683 }}

Many studies have evaluated LID; its frequency varies according to country of origin, diet, pregnancy status, age, gender, etc. Depending on these previous conditions, the frequency can vary from 11% in male athletes (Poland) to 44.7% in children less than 1 year old (China):

The frequency of LID in different countries and populations is as follows:

• Poland: 14 of 131 male athletes (11%); 31 of 121 female athletes (26%) with ID{{cite journal |title=The assessment of frequency of iron deficiency in athletes from the transferrin receptor-ferritin index |journal=International Journal of Sport Nutrition and Exercise Metabolism |volume=11 |issue=1 |pages=42–52 |date=March 2001 |pmid=11255135|last1=Malczewska |first1=J |last2=Szczepańska |first2=B |last3=Stupnicki |first3=R |last4=Sendecki |first4=W |doi=10.1123/ijsnem.11.1.42 }}
• India: 27.5% amongst student nurses{{cite journal |title=Iron deficiency amongst nursing students |journal=Indian Journal of Medical Sciences |volume=58 |issue=9 |pages=389–93 |date=September 2004 |pmid=15470280 |url=http://www.indianjmedsci.org/article.asp?issn=0019-5359;year=2004;volume=58;issue=9;spage=389;epage=393;aulast=Mehta|last1=Mehta |first1=B. C. }}
• Spain: 31 of 211 women of child-bearing age (14.7%) in Barcelona{{cite journal |first1=Maria J. |last1=Capel-Casbas |first2=Jose J. |last2=Duran |first3=Jorge |last3=Diaz |first4=Gerardo |last4=Ruiz |first5=Ramon |last5=Simon |first6=Francisco |last6=Rodriguez |first7=Josep |last7=Piqueras |first8=Dolors |last8=Pelegri |first9=Nuria |last9=Pujol-Moix |year=2005 |title=Latent Iron Metabolism Disturbances in Fertile Women and Its Detection with the Automated Hematology Instrument LH750® |journal=Blood |volume=106 |issue=11 |pages=3707 |doi=10.1182/blood.V106.11.3707.3707 |url=http://abstracts.hematologylibrary.org/cgi/content/abstract/106/11/3707 }}
• China: In 3,591 pregnant and 3,721 premenopausal women from 15 provinces, LID was found in 1,529 (42.6%) pregnant women (urban first-trimester = 41.9%; rural = 36.1%) and in 1,280 (34.4%) premenopausal non-pregnant women (urban = 35.6%; rural = 32.4%).{{cite journal |title=[Prevalence of iron deficiency in pregnant and premenopausal women in China: a nationwide epidemiological survey] |language=zh |journal=Zhonghua Xue Ye Xue Za Zhi |volume=25 |issue=11 |pages=653–7 |date=November 2004 |pmid=15634568|last1=Liao |first1=Q. K. |last2=Chinese Children |first2=Pregnant Women & Premenopausal Women Iron Deficiency Epidemiological Survey Group }} For pediatric samples: in 9,118 children from 31 provinces, aged 7 months to 7 years old, the incidence of LID was 32.5% (2,963 children). Sub-classifying the cases according to age and origin (global/countryside): less than 1 year old (7 to 12 months), LID was 44.7% (35.8% in countryside); 1 – 3 years old, LID was 35.9% (31% in countryside); 4 to 7 years old, LID was 26.5% (30.1% in countryside).{{cite journal |title=[Prevalence of iron deficiency in children aged 7 months to 7 years in China] |language=zh |journal=Zhonghua Er Ke Za Zhi |volume=42 |issue=12 |pages=886–91 |date=December 2004 |pmid=15733354|last1=Zhu |first1=Y. P. |last2=Liao |first2=Q. K. |author3=Collaborative Study Group for "The Epidemiological Survey of Iron Deficiency in Children in China" }}

{{Reflist}}

{{Medical resources

| ICD10 = {{ICD10|E|61.1}}

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{{Nutritional pathology}}

Category:Mineral deficiencies

Deficiency

Category:Red blood cell disorders