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Iron Deficiency Anemia: A Public Health Problem of Global Proportions


Sun 23 Apr 2023 | 06:52 PM
 Dr. Magdy Badran
Dr. Magdy Badran
Dr Magdy Badran

Iron deficiency anemia is a condition where there are too few red blood cells in the body due to a shortage of iron. Iron deficiency anemia is still a major global health problem. Approximately 25% of people worldwide have anemia. Iron deficiency is responsible for 50% of all anemias. Iron is important for healthy brain development and growth in children and for the normal production and function of various cells and hormones. Hemoglobin is the part of the red blood cells that binds to oxygen. When the body does not have enough hemoglobin circulating, not enough oxygen gets to all parts of the body either. As a result, organs and tissues may not function properly. 

Causes

Some common causes of iron deficiency anemia are poor diet, not enough iron in the diet, blood loss, a decreased ability to absorb iron and pregnancy.

Blood Loss

An iron deficiency may result when a person loses a lot of blood from an injury, giving birth, or heavy menstruation. Women with heavy periods are at risk of iron deficiency anemia because they lose blood during menstruation. Slow, chronic blood loss within the body — such as from a peptic ulcer, a hiatal hernia, a colon polyp or colorectal cancer — can cause iron deficiency anemia. Gastrointestinal bleeding can result from regular use of Non-steroidal anti-inflammatory drugs (NSAIDs. Ibuprofen and aspirin are two commonly prescribed NSAIDs.

Other conditions that cause blood loss and may lead to iron deficiency anemia include: esophagitis caused by stomach acid leaking through it, bilharzia, donating a large amount of blood, trauma, nosebleeds and haematuria.

Allergic Colitis

Cow’s milk protein intolerance is a common condition that causes gastrointestinal bleeding in the first year of life. It is the most common cause of chronic blood loss and anemia. It is the most common food allergy in young children affecting approximately (1.9–4.9)% of children under four years of age with a peak in the first year. It is associated with several distinct entities such as Immunoglobulin E -mediated cow’s milk protein intolerance, food protein-induced enterocolitis syndrome, food protein-induced proctitis/proctocolitis, food protein-induced enteropathy, infantile colic, GERD disease and constipation. Cow’s milk protein intolerance may present as vomiting, chronic diarrhea sometimes containing blood and mucus, hematemesis, urticaria, colicky abdominal pain. Severe massive gastrointestinal hemorrhage is a rare symptom among infants. 

Up to 50-60% of babies/children with delayed type cow’s milk protein allergy may also react to the soya protein with similar symptoms, which are usually gut-related symptoms such as abdominal pain, vomiting, diarrhea, constipation or blood in the stools in an otherwise well child. Interestingly only around 10% of babies with immediate type cow’s milk protein allergy react to the soya protein.

Pregnancy

Iron deficiency is a global nutritional problem affecting up to 52% of pregnant women. Throughout pregnancy, the amount of blood in the body increases by 20% to 30%. That means iron stores need to serve the increased blood volume as well as the need of hemoglobin for the growing fetus. Teenage mothers are another group of women at increased risk. They have a greater nutritional requirement due to their own growth spurts. Teenage pregnancies are usually unplanned, and therefore these mothers may already experience suboptimal nutritional status prior to conception making them at an even higher risk for developing iron deficiency anemia.

Malabsorption

Malabsorption occurs when the body can't absorb iron from food and is another possible cause of iron deficiency anemia. Intestinal iron absorption is critical for maintaining iron balance in the body. Iron absorption is regulated by the hepatic peptide hormone hepcidin. Iron excess stimulates hepcidin production and increased concentrations of the hormone in turn block dietary iron absorption thus preventing further iron loading. Hepcidin also controls iron release from cells that recycle or store iron, thus regulating plasma iron concentrations. 

High hepcidin levels block intestinal iron absorption and macrophage iron recycling, causing iron restricted erythropoiesis (the formation of red blood cells) and anemia. Low hepcidin levels favor bone marrow iron supply for hemoglobin synthesis and red blood cells production.

Infection and inflammation cause an increase in hepcidin synthesis resulting in decreased availability of circulating iron, which is considered to represent a defense mechanism of the human body against extracellularly proliferating (iron-dependent) pathogens. In chronic inflammatory states, this ultimately leads to a deficiency of iron available for erythropoiesis called anemia of chronic disease.  

Enhancing factors of iron absorption are vitamin C, meat, fish and poultry. The absorption rate of iron has been reported as 25–30% in the consumption of organ meats, 7–9% in green leafy vegetables, 4% in grains and 2% in dried legumes, indicating that food types or other dietary factors might influence iron bioavailability.

The most important inhibitors of iron uptake are phytic acid/phytates, polyphenols/tannins, proteins from soya beans, milk, eggs, and calcium. Polyphenols are found in the human diet mainly due to their presence in vegetables, cereals, spices, tea, coffee and cocoa. Polyphenols are known iron bioavailability inhibitors and are assumed to work similarly to phytate by forming a complex with iron. While proteins from meat were reported to be enhancers, other proteins such as eggs were indicated to be inhibitory.

An intestinal disorder, such as celiac disease, which affects the intestine's ability to absorb nutrients from digested food, can lead to iron deficiency anemia. If a part of the small intestine has been bypassed or removed surgically, that may affect the ability to absorb iron and other nutrients.

The Iron and Vitamin D Deficiency Connection

Vitamin D may influence iron metabolism and erythropoiesis, whereas iron is essential for vitamin D synthesis. Vitamin D is essential to absorb iron. It is known that a deficit of vitamin D may cause deterioration of iron status and increase the risk of anemia. Studies have suggested that vitamin D, by down-regulating pro-inflammatory cytokines and hepcidin, may increase iron availability and there is also evidence that vitamin D may support erythropoiesis. A study found that 23% of iron-deficient female athletes were three times more likely to get vitamin D deficiency. Also, vitamin D-deficient women were 2.7 times more likely to have iron deficiency. Maintaining sufficient vitamin D levels is essential for preventing inflammatory type anemia. Your body needs iron, especially your liver which also processes vitamin D. Iron is essential to make hemoglobin and myoglobin which is another protein that gives oxygen to muscles. Also, iron is necessary to synthesize connective tissue and normal cellular functioning. 

Vitamin B-12 and Iron

Vitamin B-12 activates an enzyme called methionine synthase that has many essential functions, including helping your body use folate, which is needed for production of new DNA during cell division. Normally, about 1 percent of the red blood cells in your circulation are replaced by new cells each day, so that their number always remains adequate to provide oxygen to all your cells, tissues and organs. If you don't consume enough vitamin B-12, usable folate can become low, slowing production of new red blood cells in your bone marrow. Eventually, this problem can lead to low levels of iron in your blood as old red cells wear out and die but aren't effectively replaced.

Symptoms

Iron deficiency anemia often takes a long time to develop. People may not know they have it until the symptoms are severe. A person with an iron deficiency can have general weakness, dizziness or lightheadedness, extreme fatigue, fast heartbeat, easily broken and brittle nails, paler than normal skin, chest pain, shortness of breath, headaches, cold hands and feet, soreness or inflammation of the tongue, cravings for non-nutritive things, such as dirt, starch, or ice and poor appetite, especially in children.

Complications of Iron Deficiency Anemia

Complications can occur if the iron deficiency anemia is left untreated. The complications of iron deficiency anemia include increased risk of infections, heart problems, including heart failure or an enlarged heart due to it compensating for lack of oxygen, slow growth and developmental delays in infants and children, depression and pregnancy complications, including low birth weights and an increased risk for premature birth.

Prevention

You can reduce your risk of iron deficiency anemia by choosing iron-rich foods. Foods rich in iron include red meat and poultry, seafood, legumes, dark green leafy vegetables, such as spinach and dried fruits, such as raisins and apricots. 

Choose foods containing vitamin C to enhance iron absorption. Vitamin C in citrus juices, like orange juice, helps your body to better absorb dietary iron. Vitamin C is also found in broccoli, grapefruit, kiwi, leafy greens, melons, oranges, peppers, and strawberries. Cow's milk isn't a good source of iron for babies and isn't recommended for infants under 1 year.