“Iron Man & Woman” — For hundreds of years the importance of dietary iron was common knowledge. Despite this understanding, one of the most common worldwide nutrient deficiencies is iron. This is also the only nutrient where the RDA for men is less than the RDA for young women. (3)
Every living cell contains iron, amounting to approximately 5 grams, or one teaspoon for the whole body. Iron absorption is based on a number of factors. This article provides an overview of what factors come into play in its absorption. (2)
Absorption – Controls
Once iron is absorbed it is not easily eliminated from our bodies, therefore, it is important to control iron absorption. Several mechanisms exist to regulate our body’s ability to absorb iron. Generally, iron absorption depends on:
the body’s need for iron,
its form in a particular food,
and many other factors.
Healthy people absorb approximately eighteen percent of the iron present in food, however people who are iron deficient absorb more. (2)
Absorption – Form Counts
Iron is found in different forms based on the food. The amount absorbed is influenced by the particular form. Within animal flesh, approximately forty percent of the total iron is:
hemoglobin, the form that is found in red blood cells, and
myoglobin, the pigment that is present in muscle cells.
This kind of iron is referred to as heme iron and is absorbed approximately 2 – 3 times better than nonheme iron (the simple elemental iron). Nonheme iron is the form that is added during the enrichment process to grain products. It is also found in:
vegetables, as well as
other plant foods. (2) (3)
Consuming nonheme iron with heme iron together increases the absorption of nonheme iron. Consuming more vitamin C rich foods will increase iron absorption, especially if blood iron is too low or there is inadequate dietary iron. Copper also aids with the body’s iron use.
Iron is the oldest known trace mineral critical for the growth and development of the human body. A number of factors influence its absorption, including its form (whether heme or nonheme) as well as other foods with which it is consumed. The body of knowledge is vast and this article just touches upon its absorption. The next article will further delve into what affects its absorption and its distribution.
Without the trace — minerals that is, you cannot maintain a healthy life. Also referred to as microminerals, this area of nutrition science is growing at a rapid rate. Although the importance of iron has been known for centuries, it is only within the last 50 years that scientists recognized the significance of other trace minerals. Even though only 100 milligrams or less of each of these minerals are required daily, they are as essential as major minerals for good health. (5)
This article provides a general overview of trace minerals. Discover additional key facts and findings including rich sources of specific trace minerals in this next series of articles.
The Mystery Uncovered
The importance of each micromineral is like following a good mystery, and still, evidence continues to unfold.
Scientists found a rare type of heart disease in a remote area of China. This disease was linked to a deficiency in selenium.
In 1961 other research scientists linked a zinc deficiency to dwarfism, prevalent among Middle Eastern villagers.
In the latter part of the 1960’s and early 1970’s synthetic formulas for intravenous feeding omitted some trace minerals. When recipients of these intravenous feedings showed symptoms of deficiencies, it led to the identification of these trace minerals. (1) (2)
The Difficulty in Identifying Trace Minerals
The difficulty lies in the ability to define precisely what our trace mineral needs are since only minuscule amounts are needed. In order to measure these minute amounts in both body tissues and food, highly complex technology is required.
Although the mystery continues to unfold, we are aware of iron, iodide, zinc, selenium, copper, fluoride, chromium, manganese, and molybdenum. In the next article, we will see how foods rich in vitamin C increases the absorption of minerals, and iron in particular, a trace mineral commonly found deficient in a large percent of the world’s population. (1) (2) (3) (4) (5) References: