Iron is an important mineral that the human body needs to function properly. Understanding how the body uses iron and what happens if there are deficiencies is important for health and for peak athletic performance.
Here are answers to some frequently asked questions about iron and iron deficiency.
1. What is foot-strike hemolysis?
Hemolysis means the rupturing of red blood cells. Exercise-induced hemolysis has been found in endurance runners but not in endurance cyclists, suggesting that repeated foot strikes in running destroy red blood cells (Schumacher et al. 2002).
2. Is it true that women who use oral contraceptives have higher iron stores?
Yes, a noticeable effect in women who take oral contraceptives is lighter blood loss during menstruation; as a result, iron stores are significantly higher in these women than in those who don’t use oral contraceptives (Frassinelli-Gunderson, Margen & Brown 1985).
3. What is the difference between heme iron and nonheme iron?
Dietary iron has two main forms: heme and nonheme (NIH 2014). Heme iron is found in foods that contain hemoglobin; for example, meat, poultry and fish. Plants and iron-fortified foods contain only nonheme iron. Heme iron is absorbed better than nonheme iron. Eating heme and nonheme iron together enhances iron absorption.
4. Are elderly people more vulnerable to iron deficiency?
There is little direct evidence of iron deficiency occurring in elderly men and women unless other predisposing health conditions, such as inflammatory diseases, are present.
5. Is iron deficiency more common in women?
Yes, particularly in women who are pregnant or breastfeeding or in those who have recently given birth (ASH 2014).
6. What are some animal sources of iron?
- Fish: shellfish, sardines and anchovies.
- Poultry: chicken, turkey and duck, especially liver and dark meat.
- Meat: beef, pork and lamb, especially organ meats such as liver (ASH 2014).
7. What are some plant sources of iron?
Rice, grains, iron-enriched pastas, cereals, lima beans, peas, pinto beans, black-eyed peas, broccoli, kale, turnip greens and collard greens (ASH 2014).
To read the full article which ran in the September 2014 issue of IDEA Fitness Journal click here.
ASH (American Society of Hematology). 2014. Iron deficiency anemia. www.hematology.org/Patients/ Anemia/Iron-Deficiency.aspx; accessed May 22, 2014.
Frassinelli-Gunderson, E.P., Margen, S., & Brown, J.R. 1985. Iron stores in users of oral contraceptive agents. American Journal of Clinical Nutrition, 41 (4), 703-12.
MedicineNet.com. 2014. Hematocrit. www.medicinenet.com/hematocrit/article.htm; accessed May 21, 2014. NIH (National Institutes of Health). 2014. Office of
Schumacher, Y.O., et al. 2002. Hematological indices and iron status in athletes of various sports and performances. Medicine & Science in Sports & Exercise, 34 (5), 869-75.
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