Iron Supplements: a Review

Iron supplements are often given to individuals who for some reason or another are low in Iron concentrations in their blood. This article aims to provide some clarification about what iron is, when iron deficiency can occur, who may need to take iron supplements to prevent a deficiency, and the risk of iron toxicity.

What is Iron?

Iron is an essential element that plays a key role in normal human physiology. In humans, iron combines with proteins in the blood that are responsible for the transportation of oxygen through the bloodstream. It also plays a regulatory role in cell growth and differentiation. When humans are deficient in iron (anemic) oxygen delivery to tissues is hampered, leading to fatigue, confusion, and decreased immunity. But before you run out and take a few iron supplements, keep in mind that too much iron can lead to iron toxicity and even death.

When can iron deficiency occur?

It is estimated by the WHO (World Health Organization) that iron deficiency is the number 1 nutritional disorders in the world with as much as 80% of the world afflicted. Iron deficiency occurs when the balance of iron that is taken into the body is less than what is required by the body for normal function. The process of iron deficiency is usually slow because the body will first try to compensate for the imbalance by tapping into the forms of iron storage within the body. Once the iron storage forms are depleted, blood hemoglobin levels begin to decrease leading to iron deficiency anemia.

Iron deficiency anemia can be associated with low amounts of iron being taken in through the diet, poor absorption of iron from the GI tract, or excessive blood loss. Individuals who have the greatest need for iron such as pregnant woman, woman of child bearing age, premature or low birth weight infants, older infants, and teenage girls, may be at the greatest risk of developing iron deficient anemia. Woman who tend to have very heavy menstrual flow during their period may also be at a substantial risk for developing iron deficiency.

Individuals with certain disorders such as kidney failure, vitamin A deficiencies, and absorption disorders are also open to iron deficiencies. Kidney failure can lead to an iron deficiency because these individuals have a hard time making sufficient amounts of erythropoietin, a hormone needed to make red blood cells. Vitamin A is needed to help utilize stored Iron in the body. If you have low amounts of vitamin A, stored iron can't be utilized. Absorption disorders simply do not allow the body to absorb from the diet the iron that is needed to meet the body’s needs.

Chronic inflammation caused by an infectious disease, cancer, or auto-immune disease like arthritis can lead to an iron deficiency. People with these disorders tend to take in a sufficient amount of iron to support normal health if they were healthy, but these disorders may activate a protein that is responsible for increasing the metabolism of iron.

Who needs iron supplements?

There are three types of people who may need to take iron supplements. Those who lose more iron, those who do not absorb sufficient amounts of iron and those who require more amounts of iron.  It has already been mentioned that pregnant women, woman of childbearing age, premature infants, toddlers, teenage girls, people suffering from renal failure, and people with GI disorders who do not absorb normal amounts of iron may benefit from iron supplements. Vegetarians may need to consider iron supplements as the vegetarian's diet may not be sufficient to reach the recommended daily intake of iron.  It is not just that fruits and vegetables have lower amounts of iron in them than meat, but the absorption of plant iron vs. meat iron is much more difficult in the human body.  With this in mind, a vegetarian would have consume more amounts of plant iron just to reach the same level as somebody who eats meat.

There is some evidence that suggests that men and woman who engage in regular intense exercise may have insufficient iron stores.  The three groups of athletes that may be at the highest risk of iron deficiency are female athletes, distance runners, and vegetarian athletes. These groups need to ensure that they have sufficient amounts or iron in their diet as well as take the necessary steps to ensure adequate absorption from the gut such as having sufficient amounts of Vitamin C in their diet.

It is imperative to note that men and post-menopausal women should not be taking iron supplements unless explicitly instructed to do so by their physician.

What is the risk of iron toxicity?

The risk for iron toxicity can run very high if someone is taking iron supplementation that does not need it.  This is because iron is lost from the body at a very slow rate.  Remember to keep any iron supplement away from children.  As little as 200mg has been reported to kill a child.

The institute of Medicine has set certain guidelines on the upper limit of iron intake on a daily basis for adults, children, and infants. The upper limit for adults is 45mg/day regardless if pregnant or lactating.  The same is true for teenagers 14-18. Infants and children have a maximum recommended dose of 40mg/day.  Any healthy individual taking in more than these amounts may be at risk of developing iron toxicity. Keep in mind that a physician may prescribe higher amounts of iron supplementation than these amounts and that these recommended doses are for otherwise healthy people individuals.

It is still emphasized by the Dietary Guidelines for Americans that a healthy diet be the goal and that consuming foods be the primary way that we meet our nutrient needs.