JANA DENGEL, MS. RD. LD. REGISTERED DIETITIAN AND SPORTS NUTRITIONIST
Phone Number (952) 451-6159
Iron: A Key Nutrient for Performance Disclaimer: This fact sheet provides information that should not take the place of medical advice. Talk to your doctor prior to iron supplementation.
What You Should Know about Iron
Iron is a part of proteins and enzymes that maintain health and optimal performance Iron deficiency limits oxygen delivery to cells/muscles and can result in fatigue, poor performance, and decreased immunity Those most vulnerable to anemia: distance runners, female athletes and vegetarians Approximately one in three male elite athletes may have iron deficiency More than half of female elite athletes may have iron deficiency While rare, excess amounts of iron can result in toxicity and even death
What are the Signs of Iron Deficiency Anemia?
Feeling tired and weak Decreased work and school performance Difficulty maintaining body temperature or cold hands and feet Decreased immune function, which increases susceptibility to infection Glossitis or inflamed tongue
What Causes Iron Deficiency? Inadequate iron intake Strenuous training with repeated foot strikes Sweating loss of 4 pounds body weight can result in 1-2 mg of iron loss Blood loss due to GI bleeding with high exercise intensity and distance and dehydration Blood loss due to menstruation can result in a iron loss of approximately 0.5 mg per day How Much Iron do I need? Table 3: Recommended Dietary Allowances for Iron for Children, and Adults Males Females Age (mg/day) (mg/day) 9 to 13 years
8
8
14 to 18 years
11
15
19 to 50 years
8
18
The need for iron may be 30% greater in those who engage in regular intense exercise.
JANA DENGEL, MS. RD. LD. REGISTERED DIETITIAN AND SPORTS NUTRITIONIST
Phone Number (952) 451-6159
What Foods Provide Iron? Information from U.S. Department of Agriculture, Agricultural Research Service. 2011. USDA National Nutrient Database for Standard Reference, Release 24. Nutrient Data Laboratory Home Page, http://www.ars.usda.gov/ba/bhnrc/ndl.
There are two forms of dietary iron: heme and non-heme. Heme iron is found in animal foods such as red meats, fish, and poultry. Non-heme iron is found in plant foods and is the type of iron added to ready to eat cereals and breads.
Heme Iron Foods
Mg per serving
Non-heme Iron Foods
Mg per serving
Chicken liver, pan-fried, 3 ounces
11.0
Ready-to-eat cereal, 100% iron fortified, ¾ cup
18.0
Beef liver, pan-fried, 3 ounces
5.2
Oatmeal, instant, fortified, prepared with water, 1 packet
11.0
Beef, chuck, braised 3 ounces
3.1
Soybeans, mature, boiled, 1 cup
8.8
Turkey, dark meat, roasted, 3 ounces
2.0
Lentils, boiled, 1 cup
6.6
Beef, ground, 85% lean, patty, broiled, 3 ounces
2.2
Beans, kidney, mature, boiled, 1 cup
5.2
Beef, top sirloin, steak, lean only, broiled, 3 ounces
1.6
Beans, lima, large, mature, boiled, 1 cup
4.5
Tuna, light, canned in water, 3 ounces
1.3
Ready-to-eat cereal, 25% iron fortified, ¾ cup
4.5
Turkey, light meat, roasted, 3 ounces
1.1
Blackeye peas, (cowpeas), mature, boiled, 1 cup
4.3
Chicken, dark meat, meat only, roasted, 3 ounces
1.1
Beans, navy, mature, boiled, 1 cup
4.3
Chicken, light meat, meat only, roasted, 3 ounces
0.9
Beans, pinto or black, mature, boiled, 1 cup
3.6
Crab, Alaskan king, cooked, moist heat, 3 ounces
0.7
Tofu, raw, firm, ½ cup
3.4
Pork, loin chop, broiled, 3 ounces
0.7
Spinach, frozen, chopped or leaf, boiled ½ cup
1.9
Shrimp, cooked moist heat, 4 large
0.3
Raisins, seedless, packed, ½ cup
1.6
Halibut, cooked, dry heat, 3 ounces
0.2
Molasses, 1 tablespoon
0.9
Bread, white, commercially prepared, 1 slice
0.9
JANA DENGEL, MS. RD. LD. REGISTERED DIETITIAN AND SPORTS NUTRITIONIST
Phone Number (952) 451-6159
Iron Diagnostic Testing and Supplementation Information from Gusmer, R and Dengel, D. Techniques for Track and Field and Cross Country, Volume 6, Number 1, August, 2012
Iron testing should be done 3-4 times per year to determine the normal iron levels for each athlete and monitored through seasons. A combination of diagnostic blood test should be monitored to determine iron stores and supplement needs. Recommended Diagnostic levels for Supplementation Supplement Serum Ferritin Transferrin Saturation No >40 ug/L >16% Yes <30-35 ug/L <16% Yes
< 20 ug/L
<16%
Hemoglobin >12 g/dL <12 g/dL <12 g/dL
Dose per Day None 125-325 mg ferrous sulfate 325 mg ferrous sulfate
.
Iron Supplements Information from Office of Dietary Supplements, National Institute of Health, http://ods.od.nih.gov
Supplemental iron is available in two forms: ferrous and ferric. Ferrous iron salts (ferrous fumarate, ferrous sulfate, and ferrous gluconate) are the best absorbed forms of iron supplements.
It is recommended that most people take their prescribed daily iron supplement in two or three equally spaced doses. For adults who are not pregnant, the Centers of Disease Control and Prevention recommends taking 50 mg to 60 mg of oral elemental iron (the approximate amount of elemental iron in one 300 mg tablet of ferrous sulfate) twice daily for three months for the therapeutic treatment of iron deficiency anemia. However, physicians evaluate each person individually, and prescribe according to individual needs.
Iron supplements may cause gastrointestinal side effects such as nausea, vomiting, constipation, diarrhea, dark colored stools, and/or abdominal distress.
Starting with half the recommended dose and gradually increasing to the full dose will help minimize these side effects. Taking the supplement in divided doses and with food also may help limit these symptoms. Iron from enteric coated or delayed-release preparations may have fewer side effects, but is not as well absorbed and not usually recommended.
Iron supplements should be consumed with a vitamin C source like orange juice apart from calcium (milk, yogurt, cheese or fortified calcium juices) or caffeine (tea or coffee).
Physicians monitor the effectiveness of iron supplements by measuring laboratory indices, including reticulocyte count (levels of newly formed red blood cells), hemoglobin levels, and ferritin levels. In the presence of anemia, reticulocyte counts will begin to rise after a few days of supplementation. Hemoglobin usually increases within 2 to 3 weeks of starting iron supplementation.
