Iron deficiency
Iron deficiency | |
---|---|
Other names | Sideropenia, hypoferremia |
Iron in heme | |
Specialty | Hematology |
Iron deficiency, or sideropenia, is the state in which a body lacks enough
Total body iron averages approximately 3.8 g in men and 2.3 g in women. In
Anemia is a condition characterized by inadequate
Signs and symptoms
Symptoms of iron deficiency can occur even before the condition has progressed to iron deficiency anemia.
Symptoms of iron deficiency are not unique to iron deficiency (i.e. not pathognomonic). Iron is needed for many enzymes to function normally, so a wide range of symptoms may eventually emerge, either as the secondary result of the anemia, or as other primary results of iron deficiency. Symptoms of iron deficiency include:[citation needed]
- fatigue
- dizziness/lightheadedness
- pallor
- hair loss
- twitches
- irritability
- weakness
- pica
- brittle or grooved nails
- hair thinning
- pharynx and the esophagus
- impaired immune function[5]
- pagophagia
- restless legs syndrome[6]
Continued iron deficiency may progress to
Signs and symptoms in children
- pale skin
- fatigue
- slowed growth and development
- poor appetite
- decrease in the size of testes
- behavioral problems
- abnormal rapid breathing
- frequent infection
Iron requirements in young children to teenagers
Age group | Recommended daily amount of iron[7] |
---|---|
7–12 months | 11 mg |
1–3 years | 7 mg |
4–8 years | 10 mg |
9–13 years | 8 mg |
14–18 years, girls | 15 mg |
14–18 years, boys | 11 mg |
Causes
- blood loss (hemoglobin contains iron)
- donation
- excessive menstrual bleeding
- non-menstrual bleeding
- bleeding from the colon cancer, etc.)
- rarely, laryngological bleeding or from the respiratory tract
- inadequate intake
- substances (in diet or drugs) interfering with iron absorption
- Fluoroquinolone antibiotics[8]
- malabsorption syndromes
- inflammation where it is adaptive to limit bacterial growth in infection, but is also present in many other chronic diseases such as Inflammatory bowel disease and rheumatoid arthritis
- parasitic infection
Though
Athletics
Possible reasons that athletics may contribute to lower iron levels includes mechanical
Inadequate intake
A U.S. federal survey of food consumption determined that for women and men over the age of 19, average iron consumption from foods and beverages was 13.1 and 18.0 mg/day, respectively. For women, 16% in the age range 14–50 years consumed less than the Estimated Average Requirement (EAR), for men ages 19 and up, fewer than 3%.[11] Consumption data were updated in a 2014 U.S. government survey and reported that for men and women ages 20 and older the average iron intakes were, respectively, 16.6 and 12.6 mg/day.[12] People in the U.S. usually obtain adequate amounts of iron from their diets. However, subgroups like infants, young children, teenaged girls, pregnant women, and premenopausal women are at risk of obtaining less than the EAR.[13] Socio-economic and racial differences further affect the rates of iron deficiency.[13]
Bioavailability
Iron is needed for
To reduce bacterial growth, plasma concentrations of iron are lowered in a variety of systemic inflammatory states due to increased production of
Reflecting this link between iron bioavailability and bacterial growth, the taking of oral
Diagnosis
- A complete blood count can reveal microcytic anemia,[18] although this is not always present – even when iron deficiency progresses to iron-deficiency anemia.
- Low serum ferritin (see below)
- Low serum iron
- High TIBC(total iron binding capacity), although this can be elevated in cases of anemia of chronic inflammation.
- It is possible that the fecal occult blood test might be positive, if iron deficiency is the result of gastrointestinal bleeding; although the sensitivity of the test may mean that in some cases it will be negative even with enteral blood loss.
As always, laboratory values have to be interpreted with the lab's
Serum ferritin can be elevated in inflammatory conditions; so a normal serum ferritin may not always exclude iron deficiency, and the utility is improved by taking a concurrent C-reactive protein (CRP). The level of serum ferritin that is viewed as "high" depends on the condition. For example, in inflammatory bowel disease the threshold is 100, where as in chronic heart failure (CHF) the levels are 200.[citation needed]
Treatment
Before commencing treatment, there should be definitive diagnosis of the underlying cause for iron deficiency. This is particularly the case in older patients, who are most susceptible to colorectal cancer and the gastrointestinal bleeding it often causes. In adults, 60% of patients with iron-deficiency anemia may have underlying gastrointestinal disorders leading to chronic blood loss.[19] It is likely that the cause of the iron deficiency will need treatment as well.
Upon diagnosis, the condition can be treated with
Examples of oral iron that are often used are
Low-certainty evidence suggests that IBD-related anemia treatment with
Ferric maltol, marketed as Accrufer and Ferracru, is available in oral and IV preparations. When used as a treatment for IBD-related anemia, very low certainty evidence suggests a marked benefit with oral ferric maltol compared with placebo. However it was unclear whether the IV preparation was more effective than oral ferric maltol.[21]
A Cochrane review of controlled trials comparing intravenous (IV) iron therapy with oral iron supplements in people with chronic kidney disease, found low-certainty evidence that people receiving IV-iron treatment were 1.71 times as likely to reach their target hemoglobin levels.[22] Overall, hemoglobin was 0.71g/dl higher than those treated with oral iron supplements. Iron stores in the liver, estimated by serum ferritin, were also 224.84 µg/L higher in those receiving IV-iron.[22] However there was also low-certainty evidence that allergic reactions were more likely following IV-iron therapy. It was unclear whether type of iron therapy administration affects the risk of death from any cause, including cardiovascular, nor whether it may alter the number of people who may require a blood transfusion or dialysis.[22]
Food sources
Mild iron deficiency can be prevented or corrected by eating iron-rich foods and by cooking in an iron skillet. Because iron is a requirement for most plants and animals, a wide range of foods provide iron. Good sources of dietary iron have
Iron from different foods is absorbed and processed differently by the body; for instance, iron in meat (heme iron source) is more easily absorbed than iron in grains and vegetables ("non-heme" iron sources).[25] Minerals and chemicals in one type of food may also inhibit absorption of iron from another type of food eaten at the same time.[26] For example, oxalates and phytic acid form insoluble complexes which bind iron in the gut before it can be absorbed.
Because iron from plant sources is less easily absorbed than the heme-bound iron of animal sources,
Following are two tables showing the richest foods in heme and non-heme iron.
% RDA | ||||
---|---|---|---|---|
Food | Serving size | Iron | 18 mg | 8 mg |
pork liver | 3 oz (85 g) | 15.2 mg | 84% | 190% |
lamb kidney | 3 oz (85 g) | 10.2 mg | 57% | 128% |
octopus | 3 oz (85 g) | 8.1 mg | 45% | 101% |
lamb liver | 3 oz (85 g) | 7 mg | 39% | 88% |
cooked oyster | 3 oz (85 g) | 6.6 mg | 37% | 83% |
mussel | 3 oz (85 g) | 5.7 mg | 32% | 71% |
beef liver | 3 oz (85 g) | 5.5 mg | 31% | 69% |
duck breast | 3 oz (85 g) | 3.8 mg | 21% | 48% |
bison | 3 oz (85 g) | 2.9 mg | 16% | 36% |
beef | 3 oz (85 g) | 2.5 mg | 14% | 31% |
clams[a] | 3 oz (85 g) | 2.4 mg | 13% | 30% |
lamb | 3 oz (85 g) | 2 mg | 11% | 25% |
Food | Serving size | Iron | % guideline (figs don't agree) |
---|---|---|---|
raw yellow beans | 100g | 7 mg | 35% |
spirulina | 15g | 4.3 mg | 24% |
falafel | 140g | 4.8 mg | 24% |
soybean kernels | 125ml (~1⁄2 cup) | 4.6 mg | 23% |
spinach | 125g | 4.4 mg | 22% |
lentil | 125ml (~1⁄2 cup) | 3.5 mg | 17.5% |
treacle (CSR Australia) | 20ml (1 tbsp) | 3.4 mg | 17% |
rye bread | 100g | 2.8 mg | 14% |
buckwheat | 100g | 2.2 mg | 11% |
molasses (Bluelabel Australia) | 20ml (1 tbsp) | 1.8 mg | 9% |
candied ginger root | 15g | 1.7 mg | 8.5% |
toasted sesame seeds | 10g | 1.4 mg | 7% |
cocoa (dry powder) | 5g | 0.8 mg | 4% |
Food recommendations for children
Children at 6 months should start having solid food that contains enough iron, which could be found in both heme and non-heme iron.[35]
Heme iron:
- Red meat (for example, beef, pork, lamb, goat, or venison)
- Fatty fish
- Poultry (for example, chicken or turkey)
- Eggs
Non-heme iron:
- Iron-fortified infant cereals
- Tofu
- Beans and lentils
- Dark green leafy vegetables
Iron deficiency can have serious health consequences that diet may not be able to quickly correct; hence, an iron supplement is often necessary if the iron deficiency has become symptomatic.
Blood transfusion
Blood transfusion is sometimes used to treat iron deficiency with hemodynamic instability.[36] Sometimes transfusions are considered for people who have chronic iron deficiency or who will soon go to surgery, but even if such people have low hemoglobin, they should be given oral treatment or intravenous iron.[36]
- Intravenous iron therapy for non-anaemic, iron-deficient adults
Current evidence is limited to base any recommendations that intravenous iron therapy is beneficial for treating non-anaemic, iron-deficient adults.[37] Further research in this area is needed as current body of evidence is very low quality.
Cancer research
The presence of Helicobacter pylori in the stomach can cause inflammation and can lower the threshold for the development of gastric cancer. In the setting of iron deficiency, H. pylori causes more severe inflammation and the development of premalignant lesions.[38] This inflammatory effect appears to be mediated, in part, through altered bile acid production including an increase in deoxycholic acid, a secondary bile acid implicated in colon cancer and other gastrointestinal cancers.[38]
See also
- Haemochromatosis - a condition in which the body stores too much iron
- Bahima disease
- CO2 fertilization effect
Notes
References
- ^ PMID 9563847.
- ^ "Women of reproductive age (15-49 years) population (thousands)". www.who.int.
- ^ "Iron and Iron Deficiency". Centers for Disease Control and Prevention. 23 February 2011. Archived from the original on 8 September 2014. Retrieved 12 August 2014.
- ^ "Mortality and Burden of Disease Estimates for WHO Member States in 2002" (xls). World Health Organization. 2002.
- S2CID 1108612.
- PMID 17368978.
- ^ "Is your child getting enough iron?". Mayo Clinic. Retrieved 26 April 2019.
- PMID 26205818.
- ^ ]
- ^ S2CID 32504228.
- ^ Moshfegh A, Goldman J, Cleveland L (September 2005). "Table A12: Iron" (PDF). What we eat in America, NHANES 2001-2002: usual nutrient intakes from food compared to dietary reference intakes. National Health and Nutrition Examination Survey (NHANES) (Report). US Department of Agriculture, Agricultural Research Service. Archived from the original on 6 January 2015.
- ^ "What We Eat In America, NHANES 2013-2014" (PDF). National Health and Nutrition Examination Survey (NHANES). US Department of Agriculture, Agricultural Research Service.
- ^ a b "Iron". Fact Sheet for Health Professionals. Office of Dietary Supplements. National Institutes of Health. February 2020.
- PMID 760197.
- ^ ISBN 978-0-679-74674-4.
- ISBN 978-1-4612-3956-7.
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- ^ PMID 33471939.
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- ^ "Iron deficiency". UK Food Standards Agency. Archived from the original on 8 August 2006.
- ^ "Iron in diet". MedlinePlus. U.S. National Library of Medicine.
- ^ Reed M. "Iron in the vegan diet". The Vegetarian Resource Group.
- ^ "Iron". The Merck Manuals Online Medical Library. Archived from the original on 17 October 2015. Retrieved 27 October 2015.
- ^ PMID 37665781.
- ^ "Food Sources of Iron". Dietary Guidelines for Americans. USDA CNPP; HHS Office of Disease Prevention and Health Promotion. Archived from the original on 26 March 2024.
- ^ "Dietary Reference Intakes: Recommended Intakes for Individuals" (PDF). National Academy of Sciences. Institute of Medicine. Food and Nutrition Board. Archived from the original (PDF) on 6 September 2013.
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- ^ CDC (3 December 2018). "Iron - Infant and Toddler Nutrition". Centers for Disease Control and Prevention. Retrieved 26 April 2019.
- ^ ABIM Foundation, American Association of Blood Banks, archived from the originalon 24 September 2014, retrieved 25 July 2014, which cites
- AABB (2011). Guidelines for Patient Blood Management and Blood. ISBN 978-1-56395-333-0. Archived from the originalon 15 October 2014. Retrieved 28 July 2014.
- Lin DM, Lin ES, Tran MH (October 2013). "Efficacy and safety of erythropoietin and intravenous iron in perioperative blood management: a systematic review". Transfusion Medicine Reviews. 27 (4): 221–34. PMID 24135037.
- AABB (2011). Guidelines for Patient Blood Management and Blood.
- PMID 31860749.
- ^ a b Noto JM, Piazuelo MB, Shah SC, Romero-Gallo J, Hart JL, Di C, Carmichael JD, Delgado AG, Halvorson AE, Greevy RA Jr, Wroblewski LE, Sharma A, Newton AB, Allaman MM, Wilson KT, Washington MK, Calcutt MW, Schey KL, Cummings BP, Flynn CR, Zackular JP, Peek RM Jr. Iron deficiency linked to altered bile acid metabolism promotes Helicobacter pylori-induced inflammation-driven gastric carcinogenesis. J Clin Invest. 2022 Mar 22:e147822. doi: 10.1172/JCI147822. Epub ahead of print. PMID 35316215
Further reading
- Gropper SS, Smith JL, Groff JL (2009). "Enhancers and inhibitors of iron absorption". Advanced Nutrition and Human Metabolism (5th ed.). Belmont, California: ISBN 978-0-495-11657-8.
- Umbreit J (March 2005). "Iron deficiency: a concise review". American Journal of Hematology. 78 (3): 225–31. PMID 15726599.
- Nutrition,Iron (2018).Centers for Disease Control and Prevention.
- "Iron deficiency in children: Prevention tips for parents". The Mayo Clinic. 10 December 2019.
External links
- "Recommendations to Prevent and Control Iron Deficiency in the United States". U.S. Centers for Disease Control and Prevention.
- "Advice for Improving your Iron Intake" (PDF). University of South Hampton, NHS Foundation Trust. Archived from the original (PDF) on 29 November 2015.