Iron in Foods

Iron, a mineral, is an essential micronutrient. It is in all cells of the human body and is known to have many vital functions. It is the major component of hemoglobin in red blood cells and of numerous enzymes. It carries oxygen from the lungs to all parts of the body and facilitates oxygen use and storage in muscles. Every cell in the body needs iron to produce energy. Inadequate intake and absorption of iron leads to depletion of iron stores and iron deficiency anemia.

Adequate iron intake through a varied diet of iron rich, bioavailable foods and /or iron supplementation significantly reduces iron deficiency and iron deficiency anemia (microcytic hypochromic anemia), in which the size and number of red blood cells are reduced. 

Benefits of Iron

Adequate iron intake:

• Decreases fatigue and apathy

• Increases work capacity and economic productivity

• Increases ability to fight infection

• Maintains body temperature

• Decreases pica

• Improves pregnancy outcomes

1. Decreases risk of death from hemorrhage, spontaneous abortion, stress of labor and other delivery complications
2. Decreases chance of preterm delivery, low birth weight and mortality

• Improves fetal / infant health

1. May improve iron status for first 6 months
2. Decreases susceptibility to lead poisoning
3. Decreases cognitive impairment and developmental delay

Foods Rich in Iron

There are two types of iron in the foods we eat: heme and non-heme. Non-heme iron is not absorbed well by the body as heme iron. However, the absorption of non-heme iron is greatly improved if foods rich in Vitamin C are included in the meal.

For Non-Vegetarians	For Vegetarians
Heme Iron	Non-Heme Iron + Vitamin C-rich Foods
Meat Poultry Fish	Eggyolk
	Whole wheat bread
	Whole grain cereals
	Green leafy vegetables
	Nuts
	Seeds

Recommendations for Iron

The Dietary Reference Intake (DRI) for iron varies with age and reproductive status, including menstruation, pregnancy and lactation. It also depends on the type of iron consumed, i.e. heme or non-heme iron. The requirement for iron is 1.8 times higher for vegetarians.

Dietary Reference Intake (DRI) (2) DRI Dietary Reference Intake	Reproductive Status	Milligrams of Iron Per Day For 14-18 Year Old Females	Milligrams of Iron Per Day For 19-50 Year Old Females
EAR Estimated Average Requirement	Nonpregnant, menstruating Pregnant Lactating, non menstruating	7.9 23 7	8.1 22 6.5
RDA Recommended Dietary Allowance	Nonpregnant, menstruating Pregnant Lactating, non menstruating	15 27 10	18 27 9
UL Tolerable Upper Intake Level	Nonpregnant, menstruating Pregnant Lactating, non menstruating	45 45 45	45 45 45

Consequences of Excessive Iron

The Tolerable Upper Intake Level (UL) of iron is the highest level of daily iron intake, likely to have no adverse health effects on most healthy individuals.

• Acute iron toxicity can result from overdoses of medicinal iron. 

• Excessive intake of iron supplements reduces zinc absorption. Women need 15 mg zinc and 2 mg copper daily when daily intake of iron exceeds 30 mg of elemental iron (3).                              

• Excessive intake of iron may also result in gastrointestinal effects such as constipation, nausea, vomiting and diarrhea.

• Researchers are studying cardiovascular and cancer risk associated with increased body iron stores. Hereditary hemochromatosis is characterized by excessive absorption of iron.

References:

Healing Wonders of Diet Effective Guide to Diet Therapy p.239 © 2003 Philippine Publishing House ISBN 971-581-013-6

http://www.cdph.ca.gov/healthinfo/healthyliving/childfamily/documents/mo-agb-ironhandout.pdf Retrieved on April 18, 2011