Iron and Iron Deficiency

What is iron and why do we need it?

Iron is a mineral needed by our bodies. Iron is a part of all cells and does many things in our bodies. For example, iron (as part of the protein hemoglobin) carries oxygen from our lungs throughout our bodies. Having too little hemoglobin is called anemia. Iron also helps our muscles store and use oxygen.
Iron is a part of many enzymes and is used in many cell functions. Enzymes help our bodies digest foods and also help with many other important reactions that occur within our bodies. When our bodies don't have enough iron, many parts of our bodies are affected.

What is iron deficiency and why is it a concern?

Iron deficiency is a condition resulting from too little iron in the body. Iron deficiency is the most common nutritional deficiency and the leading cause of anemia in the United States.¹
The terms anemia, iron deficiency, and iron deficiency anemia often are used interchangeably but equivalent. Iron deficiency ranges from depleted iron stores without functional or health impairment to iron deficiency with anemia, which affects the functioning of several organ systems.²
Iron deficiency is a concern because it can:

• Iron deficiency can delay normal infant motor function (normal activity and movement) or mental function (normal thinking and processing skills).^3,4,5,6
  
• Iron deficiency anemia during pregnancy can increase risk for small or early (preterm) babies.^7,8 Small or early babies are more likely to have health problems or die in the first year of life than infants who are born full term and are not small.
  
• Iron deficiency can cause fatigue that impairs the ability to do physical work in adults.^9,10 Iron deficiency may also affect memory or other mental function in teens.¹¹

• What causes iron deficiency?

  Iron deficiency has many causes. (See table below for a summary). These causes fall into two main categories:
  
• Increased iron needs

Many common conditions can cause people to need additional iron:

• Because of their rapid growth, infants and toddlers need more iron than older children. Sometimes it can be hard for them to get enough iron from their normal diet.
  
• Women who are pregnant have higher iron needs. To get enough, most women must take an iron supplement as recommended by their healthcare provider.
  
• When people lose blood, they also lose iron. They need extra iron to replace what they have lost. Increased blood loss can occur with heavy menstrual periods, frequent blood donation, as well as with some stomach and intestinal conditions (food sensitivity, hookworms.)
  

2. Decreased iron intake or absorption (not enough iron taken into the body)

The amount of iron absorbed from the diet depends on many factors:

• Iron from meat, poultry, and fish (i.e., heme iron) is absorbed two to three times more efficiently than iron from plants (i.e., non-heme iron).
  
• The amount of iron absorbed from plant foods (non-heme iron) depends on the other types of foods eaten at the same meal.
  
• Foods containing heme iron (meat, poultry, and fish) enhance iron absorption from foods that contain non-heme iron (e.g., fortified cereals, some beans, and spinach).
  
• Foods containing vitamin C (see Dietary Sources of vitamin C) also enhance non-heme iron absorption when eaten at the same meal.
  
• Substances (such as polyphenols, phytates, or calcium) that are part of some foods or drinks such as tea, coffee, whole grains, legumes and milk or dairy products can decrease the amount of non-heme iron absorbed at a meal. Calcium can also decrease the amount heme-iron absorbed at a meal. However, for healthy individuals who consume a varied diet that conforms to the Dietary Guidelines for Americans, the amount of iron inhibition from these substances is usually not of concern.
  
• Vegetarian diets are low in heme iron, but careful meal planning can help increase the amount of iron absorbed.
  
• Some other factors (such as taking antacids beyond the recommended dose or medicine used to treat peptic ulcer disease and acid reflux) can reduce the amount of acid in the stomach and the iron absorbed and cause iron deficiency.

Increased Iron Needs	Decreased Iron Intake and Absorption
Rapid growth Pregnancy Blood loss Heavy menstrual periods Frequent blood donation Some stomach and intestinal conditions (food sensitivity, hookworms)	Lack of heme iron sources in the diet (e.g., vegetarian diets) Low absorption Taking antacids beyond the recommended dose or medicine used to treat peptic ulcer disease and acid reflux can reduce the amount of iron absorbed in the stomach.