Iron deficiency

Iron deficiency affects a large proportion of the world’s population, an estimated 12% of the world population. This problem is especially relevant in females of childbearing potential, children, and those in low- and middle-income countries, the latter being due to insufficient nutrition. A deficiency could potentially be due to either lacking dietary intake, reduced absorption of iron taken, or blood loss.

Blood loss is the main cause in resource-rich populations, as dietary intake is usually adequate.  Overt bleeding is not difficult to recognize by the clinician or the patient and could be due to trauma, blood in vomitus or stools, blood when coughing, heavy menstrual bleeding, pregnancy and delivery and blood in the urine.

Blood in the vomitus could be due to a bleeding stomach ulcer or bleeding high up in the gut or due to liver disease causing varices in the esophagus, and blood in the stools (called melena, which is bad smelling, and tar-like in appearance) could be due to a cancerous growth in the bowels or hemorrhoids (typically the blood is visible when passing stools but it is not mixed with the stools but surrounds it).

Other causes of blood loss can be more problematic to identify, frequent blood donation, underestimation of menstrual blood loss, occult bleeding (due to gastritis, cancer, blood vessel pathology) and parasites (hookworm, whipworm). Occult bleeding refers to bleeding that is not seen by the naked eye and can only be seen when samples (stools, urine) are sent to the laboratory for evaluation.

Iron is absorbed in the upper gastrointestinal tract. Reduced iron absorption in the gut, is not a common cause of iron deficiency but can be a problem in patients who have celiac disease (also known as gluten-sensitive enteropathy, where gluten causes severe inflammation of the small bowel), atrophic gastritis (auto-immune disease, antibodies against certain cells in the stomach lining) and Helicobacter pylori infection (the organism prominent in patients with stomach ulcers), or those who have had bariatric surgery (procedure to reduce the stomach size) to aid weight loss.

It should be noted that iron from a meat source, is better absorbed than iron from other plant or grain sources, therefore iron deficiency is more common in vegetarians.

Dietary sources of iron
Dietary sources of iron are listed below and is divided into high-iron and moderate-iron content:

High-iron:  fortified cereals, kidney/liver of beef/chicken/calf, nuts, prune juice and sunflower seeds
Moderate-iron:  dried almonds, dried beans and peas, cooked meat (beef, ham, lamb, turkey), raisins, spinach, dried prunes

Some foods/chemicals may impair iron absorption such as tannates (found in tea), phosphates (found in whole grains and seeds), and foods high in calcium.

Patients usually present with anemia (low red blood cells) as the first sign of iron deficiency. Typical symptoms of anemia are fatigue, headache, weakness, exercise intolerance, pica (craving for substances that are not fit as food) and restless leg syndrome.

The physical examination of patient with iron deficiency (with or without anemia), could reveal the following: pallor (being pale), atrophic glossitis (inflammation of the tongue with a dry mouth, reduced tongue papillae or painful tongue), hair loss (in severe cases), dry or rough skin and “spoon nails”.

When an iron deficiency is suspected, blood tests are needed to confirm the diagnosis. The clinician will request a full blood count (FBC) as well as iron studies. The full blood count will typically reveal a low red blood cell count as well as a low hemoglobin and hematocrit.

These are all indicative of anemia.

Iron study panel
The iron study panel have several components, we will discuss the most common components of iron study panel here:

Serum iron: this test measures circulating iron, it is usually low in patients with iron deficiency and in those with anemia due to chronic disease or anemia of inflammation.

Serum transferrin: transferrin is a circulating transport protein for iron. Transferrin will be increased in iron deficiency and reduced in anemia due to chronic disease.

Transferrin saturation (TSAT): this result is the ration of serum iron to Total Iron Binding Capacity (TIBC). In iron deficiency, iron is reduced, TIBC is increased therefore resulting in lower transferrin saturation.

Serum ferritin: ferritin is the circulating iron storage protein that is increased in proportion to iron stores. Ferritin is an acute phase reactant that can increase independently of iron status in cases where inflammation, infection, liver disease, malignancy, and heart failure. There is a difference in opinion on which value should be used as the cut-off, most agree that a level of less than 30ng/ml is indicative of iron deficiency.

More tests can be done but the above should assist the medical professional to conclude, whether there is possible pathology and whether to pursue further testing. It is important to determine the cause of iron deficiency and to treat it accordingly. Iron deficiency can be rectified by taking iron supplements or in certain cases, to get intravenous iron via an infusion.

Dr. Janet Strauss is a Medical Doctor and the Chief Operational Officer at Medwell SA – The Home Health Care Specialists.
For more information visit www.medwell.co.za