Iron Deficiency, the most common nutritional deficiency.

Who is at Risk of Developing Iron Deficiency Anemia (IDA)?

Iron deficiency anemia (also referred to as microcytic anemia) is the most common nutritional deficiency across the globe (1). According to latest statistics, more than one-fourth of the world’s population is anemic (corresponding to 1.6 billion individuals); with 50% of the disease burden attributed to iron deficiency anemia (2).

The pathophysiology of IDA revolves around the depletion of body iron stores due to poor dietary intake, excessive utilization or a combination of both. Since iron is the primary component of hemoglobin, a moderate to severe decline in the stored iron can lead to compromised production of red blood cells and resulting circulatory dysfunction.

 

Who is at risk of developing Iron deficiency anemia?

The concentration of stored iron varies from person to person and depends on factors such as age, gender, iron intake and loss, and rate of iron utilization. According to clinical data and research statistics, young children and reproductive aged women are at a much higher risk of developing IDA (2).

 

1. Infants and Young Children

Significant quantities of iron are needed for the optimal growth and development in young children. It is imperative to mention that infants are born with reserved stores of iron at the time of birth which are usually utilized during first 4 to 6 months of extra-uterine life (12). In addition, maternal breastmilk is also a great source of iron.

Unfortunately, babies with following risk factors have insufficient iron stores and are therefore more prone to develop IDA in the absence of supplementation (3):

• Low birth weight babies (5.5 pounds or less at the time of birth)
• Babies born prematurely (before 37 weeks of gestation).
• Excessive consumption of unfortified cow’s milk is also known to cause deficiency of iron, since cow milk is low in iron content compared to human milk
• Babies of Alaskan, Native American and African-American origin.

Certain dietary choices can aggravate the risk of developing IDA in young children:

• Study reported in the Journal of Pediatrics (3) suggested that excessive milk consumption interferes with the absorption of dietary iron. The risk is even higher in babies who are born with cow milk protein allergy.
• Delayed weaning or excessive dependence on maternal milk after 6 months of age leads to iron deficiency anemia due to inadequate iron intake. According to a cross-sectional study conducted on 1647 healthy children (average age 36 months), it was discovered that the risk of developing iron deficiency increases by 4.8% with every additional month of delayed weaning or continued breastfeeding (4)
• Consumption of water contaminated with lead or exposure to lead in other forms (such as paints or soil) can aggravate the risk of lead poisoning, which may interfere with the formation of hemoglobin thus, leading to iron deficiency anemia (10,11,12).

According to latest statistics reported by Centers for Disease Control and Prevention, the prevalence of IDA in school-aged children is 1-3% (5).

 

2. Reproductive-aged Women

The average iron loss in an average non-menstruating adult is 1 mg/day. Women in reproductive age group loses up to 2.5% extra iron per day (6). According to clinical studies, an average woman loses up to 10 mg of iron in each menstrual cycle; however, this loss can exceed 42mg per cycle in females who experiences menorrhagia (6). Needless to say, these women are at high risk of developing iron deficiency anemia. Certain other factors can also make a female more prone to iron deficiency; such as (1):

• Being underweight or malnourished
• History of a chronic sickness
• Mexican or African American origin – the prevalence of IDA in white Americans is 7.1% as opposed to 25% in black women

According to latest statistics reported by CDC, the prevalence of IDA in reproductive-aged women is 3-5%, which corresponds to 3.3 million females (5).

Requirement of iron increases 2-3 folds during pregnancy to compensate for the changes in the plasma volume and placental circulation. According to statistics reported in the CDC annual report, more than 50% of women develop iron deficiency anemia during pregnancy. To minimize the risk of anemia, experts recommend that a pregnant female must consume at least 1200mg of Iron in supplemental forms from conception to childbirth (7).

 

3. Anemia in Adult Males and Non-Reproductive-aged Women:

The prevalence of anemia in non-menstruating women and adult males is generally low (1-2%). However, some common risk factors that may aggravate the risk of developing IDA are:

• Internal bleeding: Conditions like cancer of colon, intestinal bleeding and chronic ulcers are associated with significant loss of blood; thereby leading to iron deficiency anemia. It is imperative to mention that iron deficiency anemia in elderly subjects (older than 65 years) should always be investigated thoroughly for possible risk of gastrointestinal malignancy (8). According to another study, 6% of adults who present with iron deficiency anemia have occult gastrointestinal cancer (9). Excessive use of aspirin can also cause internal bleeding, resulting in iron deficiency.
• Gastric bypass surgery: Gastric or gut resection surgeries interferes with the absorption and assimilation of dietary iron.
• Patients on kidney dialysis: Dialysis patients are also at high risk of developing iron deficiency anemia due to direct loss of blood. Furthermore, kidneys produce erythropoietin (which is required for the production of red blood cells). With compromised renal functions, the secretion of hormone also suffers a great deal.
• Blood Donations: Individuals who donate blood frequently develops IDA, which can be prevented by consuming supplemental formulations of Iron (up to 20 mg/ day) with Vitamin C (1).  
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Dietary factors:

Certain dietary and lifestyle choices can lead to iron deficiency anemia; such as:

• Prolong intake of extremely low fat diet
• Malnutrition due to socioeconomic issues or health problems
• Intake of fiber rich diet, as fiber interferes with iron absorption
• Limited intake of meat and fish, as animal products are best sources of heme.

Early identification and prompt management of iron deficiency anemia is helpful at minimizing the risk of complications. Experts recommend that individuals who are at risk of developing IDA should consider following interventions to replenish iron stores in the body:

• Incorporate iron rich foods in your diet: For example, dark green vegetables such as spinach are great source of bioavailable iron. Cereals, tofu, dry fruits, beans are also enriched with iron.
• Consider iron supplements: Symptomatic iron deficiency is ideally managed with iron supplementation. The dosing frequency and duration of regimen vary according to age of patient, severity of anemia and nature of formulation.

Speak to a primary care provider to learn more about iron deficiency anemia and if you are a candidate for iron supplementation.

 

 

References:

1. http://www.aafp.org/afp/2007/0301/p671.html
2. Pasricha, S. R., Drakesmith, H., Black, J., Hipgrave, D., & Biggs, B. A. (2013). Control of iron deficiency anemia in low-and middle-income countries. Blood, 121(14), 2607-2617.
3. Vanderhoof, J. A., & Kleinman, R. E. (2015). Iron Requirements for Infants with Cow Milk Protein Allergy. The Journal of pediatrics, 167(4), S36-S39.
4. Maguire, J. L., Salehi, L., Birken, C. S., Carsley, S., Mamdani, M., Thorpe, K. E., … & Parkin, P. C. (2013). Association between total duration of breastfeeding and iron deficiency. Pediatrics, 131(5), e1530-e1537.
5. Powers, J. M., Mccavit, T. L., Adix, L., & Buchanan, G. R. (2015). Low Dose Once Daily Oral Iron Treatment of Young Children with Nutritional Iron Deficiency Anemia. Blood, 126(23), 2147-2147.
6. McDonagh, M. S., Blazina, I., Dana, T., Cantor, A., & Bougatsos, C. (2015). Screening and routine supplementation for iron deficiency anemia: a systematic review. Pediatrics, 135(4), 723-733.
7. https://www.cdc.gov/mmwr/preview/mmwrhtml/00051880.htm#00003036.htm
8. Silva, A. C., Sheppard, Z. A., Surgenor, S. L., Williams, E. J., Thomas, P. W., & Snook, J. A. (2014). Clinical risk factors for underlying gastrointestinal malignancy in iron deficiency anaemia: the IDIOM study. Frontline Gastroenterology, flgastro-2013.9.
9. Miller, J. L. (2013). Iron deficiency anemia: a common and curable disease. Cold Spring Harbor perspectives in medicine, 3(7), a011866.10.
10. JAIN, Akshat, WOLFE, Lawrence C., et JAIN, Ginee. Impact of lead intoxication in children with iron deficiency anemia in low-and middle-income countries. Blood, 2013, vol. 122, no 13, p. 2288-2289.
11. SHORT, Matthew W. et DOMAGALSKI, Jason E. Iron deficiency anemia: evaluation and management. American family physician, 2013, vol. 87, no 2.
12. PARK, Sangkyu, SIM, Chang Sun, LEE, Heun, et al. Effects of iron therapy on blood lead concentrations in infants. Journal of Trace Elements in Medicine and Biology, 2014, vol. 28, no 1, p. 56-59.
13. Iron needs of babies and children. Paediatrics & Child Health. 2007;12(4):333-334.