Why Do We Need Iron?
Red blood cells contain a protein called hemoglobin, whose function is to transport oxygen to all parts of the body. Iron is a critical component of hemoglobin. Normally, the total amount of iron in our body is around 3-4g. About 75% of this iron is associated with hemoglobin and another muscle protein called myoglobin. The remaining 25% is stored in our body in various tissues to be released for contingencies.
Whenever the supply of iron for the normal synthesis of hemoglobin falls, symptoms of iron deficiency anemia develop.
The normal hemoglobin value ranges from 12 to 17 grams and is slightly higher in males as compared to females. The normal reference values in the Western countries and the corresponding Indian reference ranges are as follows:
|Men (g%)||Women (g%)|
|Western||13.5 – 17.5||12 – 15.5|
If the value of hemoglobin falls below the reference range, then the person is said to suffer from anemia.
The dietary requirements (recommended dietary allowance or RDA) of iron are higher in women than men. This requirement is further increased during pregnancy and lactation. It is important that this additional requirement is provided by iron supplements. The RDA of iron supplements for various groups is as follows:
|Population group||RDA (mg)|
In general, iron deficiency anemia is more common in women because of monthly menstrual blood loss and blood loss during childbirth.
Causes of Iron Deficiency Anemia
- Deficiency in diet
- Malabsorption states – examples include surgical removal of stomach (gastrectomy), inflammation of stomach lining (auto-immune gastritis) or gluten allergy and inflammation (gluten induced enteropathy).
- Increased demand states (especially associated with dietary deficiency) – pregnancy, growth states.
- States of chronic blood loss – abnormal bleeding from the uterus (menorrhagia), bleeding from stomach - peptic ulcer or esophageal varices, piles, colitis, diverticulitis, drug induced bleeding due to irritation of stomach lining (e.g. aspirin) and hookworm infestation.
Symptoms and Signs of Iron Deficiency Anemia
- Pale appearing mucous membranes of eyes and tongue.
- Severe iron deficiency can lead to brittle and spoon shaped nails (koilonychia), sores at the corners of the mouth and atrophy of the taste buds.
- Person may have difficulty in swallowing (dysphagia) due to pharyngeal web formation (Plummer – Vinson syndrome).
- Pica - wanting to eat non-food items such as mud (common in children).
- Breathlessness on exertion, fatigue, increased heart rate or palpitations and headaches.
As mentioned, iron deficiency anemia can be treated easily. Drugs used to treat this condition are termed hematinics or iron supplements. They are administered either orally, intra-muscularly or intravenously to treat or prevent iron deficiency anemia in susceptible groups example pregnant women.
It is important to investigate thoroughly and determine the cause of iron deficiency and treat that condition too. Common examples include:
- Menstrual problems
- Hookworm infestation
- Cancer stomach or colon
Oral Iron Supplements
In general easily dissociable ferrous salts are preferred since they are low-cost, have high iron content and are well absorbed compared to ferric salts.
The amount of elemental iron is more important than the quantity of iron per dose unit.
Sustained release preparations are expensive and not effective. In general, liquid iron preparations are less effective and may stain the teeth. If taken, they should be placed at the back of the tongue and swallowed.
Absorption is best on empty stomach, but side-effects may occur. Thus, a larger dose may be taken with meals or a smaller dose in between meals.
Unless the deficiency is severe, the preferred route of drug administration is oral. In severe cases, when a rapid rise in hemoglobin levels is desired, iron may be administered
parenterally, by intramuscular or intravenous route.
This route is also preferred in cases where the patient is unable to tolerate oral iron preparations due to side effects or malabsorption states limit absorption of iron in the gastrointestinal tract (GIT).
- Highly useful in the management of iron deficiency anemia. When the patient is responding to therapy, the hemoglobin usually rises at a rate of 0.5-1g% every week. The response is faster during early stages of treatment, when the deficiency is more severe.
Treatment has to be continued for 1-3 months to achieve normal hemoglobin levels and for two to three months thereafter to replenish the iron stores.
- Necessary in patients who are administered erythropoietin (example - kidney failure), since body is unable to mobilise the sudden increased requirement of iron needed to keep with the demand of erythropoiesis.
- As dietary supplement during pregnancy and infancy
These two populations are at risk for development of iron deficiency anemia unless medicinal supplements are administered.
- Treatment of megaloblastic anemia ( due to vitamin deficiency) may unmask latent iron deficiency. Iron supplements are also useful in such patients.
These are common even with therapeutic doses and include:
- Metallic taste,
- Epigastric (a segment in the abdomen) pain,
- Constipation is more common due to astringent action of iron.
As mentioned above, the side effects may be minimized by taking the medication with meals.
Dietary Sources of Iron
The following foods form good source of dietary iron
Iron rich foods
- Dry beans
- Dry fruits
- Wheat germ
- Egg yolk
Moderately Iron rich foods
Poor Source of Iron
- Milk and milk products
- Root vegetables
Health Tips - Prevention is better
- Necessary to eat a proper balanced diet. Vegetarians, especially should include greens at least thrice a week.
- Avoid self-medication with pain killers. Consult a doctor.
- Women, especially in childbearing age should have regular health check-ups and blood tests, at least once a year if not more.
- Medical Biochemistry, Fourth Edition, John. W. Baynes PhD
- Quick Review of Biochemistry for Undergraduates, Krishnananda Prabhu MD, Jeevan K Shetty MD
- Haematology at a glance, Fourth edition, Atul. B. Mehta, A. Victor Hofbrand Wiley-Blackwell
- Essentials of Medical Pharmacology, Sixth edition, K.D. Tripathi MD
- The Nutrition Foundation of India (NFI) - http://nutritionfoundationofindia.org/)
- Apollo Hospital Education and Research Centre - (http://aherf.org/)
- Iron Supplements for Women - (http://www.mayoclinic.org/)
Latest Publications and Research on Iron Supplements for WomenLong-Term Dose-Response Condensed Tannin Supplementation Does Not Affect Iron Status or Bioavailability. - Published by PubMed
A retrospective study of supplemental iron intake in singleton pregnancy women with risk of developing gestational diabetes mellitus. - Published by PubMed
Comparison of hematological parameters, iron levels, and oxidative stress in women with and without breast cancer: A case- control study. - Published by PubMed
Iron absorption from oral iron supplements given on consecutive versus alternate days in iron-depleted women. - Published by PubMed
A community-based cluster randomised controlled trial in rural Bangladesh to evaluate the impact of the use of iron-folic acid supplements early in pregnancy on the risk of neonatal mortality: the Shonjibon trial. - Published by PubMed