I’m sure you’ve heard of the term “trace minerals.” But what exactly are they? They’re essential minerals that work with enzymes throughout your body. Necessary, but only in small amounts.

We get our trace minerals from many food sources – depending on the soil and water composition in which the foods were grown and on how the food was processed.

As well, many factors in our diet and within our bodies affect how much of the mineral our body actually absorbs (bioavailability). You get the most trace minerals from unprocessed whole foods.

But we have to be careful with trace minerals because it is easy to take too much. Because we need such a small amount, they become toxic when we get a lot more than the estimated daily requirement.

Don’t make a habit of taking more because your body stores these minerals and does not get rid of them easily.

If you want to take a supplement, look for ones that just contain the recommended daily value.

Balancing trace minerals can be a little tricky because they interact with each other.

So, too much of one can cause a deficiency of another: a slight magnesium overload may aggravate an iron deficiency; an iron deficiency makes you vulnerable to lead poisoning; and Vitamin C helps your body absorb iron, but prevents it from absorbing copper.

That’s why too much or too little of the trace minerals may hurt you. Now let’s look at one specific trace mineral – iron.

Most of the body’s iron is found in two proteins: hemoglobin (in red blood cells) and myoglobin (in muscle cells). Iron helps these cells accept, carry, and release oxygen. Iron is also found in many enzymes that break down compounds during metabolism.

These enzymes use iron to make amino acids (protein), hormones, and neurotransmitters (nerves).

Iron makes sure that your whole body is getting the oxygen it needs.

Because it is a trace mineral, the body handles iron carefully. Very little is excreted, so the body keeps things in balance by regulating how much iron it absorbs.

In digestion, iron is absorbed and held in the mucosal cells of the small intestine.

When iron levels get a little low, some of this stored iron gets transferred through a series of proteins into the blood, which carries it to the depleted areas throughout the body.

Some iron is lost when the mucosal cells in the intestine are replaced (about every three days) and excreted.

But not all sources of iron are equal.

How easily the body absorbs iron depends on what kind of iron it is: “heme” or “non-heme.” Heme iron is only found in meats. Non-heme iron comes from both meats and plants. On average, about 10% of the iron you get in a day is from heme sources.

But since it is absorbed so easily (about 23% absorption), this low percentage of intake contributes significantly to your body’s iron level.

Your body can’t absorb the non-heme iron quite so well. Only from two to 20 per cent is absorbed. How much iron your body absorbs also depends on other things going on in your body at the time.

Some foods actually include an ingredient that helps your body absorb more iron. Meat, fish and poultry contain the heme iron but also a factor (MFP) that boosts your body’s ability to absorb non-heme iron from other foods eaten at the same time. Vitamin C and some acids and sugars do too. So having a glass of orange juice and eating meats with other sources of iron will help you get the most out of the other sources too.

Other foods make your less able to use the iron by not allowing it to get broken down. Some of these are: soy products; whole grain cereals; nuts; the calcium and phosphorus in milk; EDTA additives in foods; the tannic acid in tea, and coffee and a few fruits and vegetables. So don’t eat these at the same time you eat your iron-rich foods.

Even so, at best, only about 10-15 per cent of the dietary iron you eat gets used.

Most iron gets used in the bone marrow to make new red blood cells. Our bodies are very efficient and don’t waste much.

A red blood cell only lasts about four months, after that the spleen and liver remove it from the blood, take it apart and prepare the parts for recycling.

Any extra iron is stored in the liver, bone marrow and spleen.

Although iron deficiencies are not common in North America, one of the most common causes is through blood loss. For example, in an active ulcer the bleeding may not be obvious but even small chronic blood losses may deplete your iron reserves. This is also true for women and people who donate blood often.

There are three stages in developing an iron deficiency. First, the stored iron diminishes.

Second, the body has less iron to transport throughout the body. Third, the body can’t produce hemoglobin.

Without enough hemoglobin, you may become anemic.

In iron deficiency anemia, the red blood cells are pale and small. They can’t carry enough oxygen from the lungs to the tissues, so energy and metabolism in the cells goes down.

You feel tired, weak and apathetic. You get severe headaches, and can’t keep warm when it’s cold out.

Since the red pigment of the blood gives the skin its color, people with an iron deficiency appear quite pale. In a dark-skinned person the eye lining – normally pink – will become pale.

Not enough iron can also affect how you act. You won’t be able to work as hard, or be as productive as you would like.

You have less energy to think, play or learn-so you’ll do these things less. You seem unmotivated, apathetic and less physically fit. You won’t be able to fight infections and are sick more often.

If you have these symptoms, ask your doctor for a hemoglobin or hematocrit test.

See if you need an iron boost. And go to the grocery store and start eating more of these iron-rich foods: clams, beef liver, tofu, shrimp, tomato juice, parsley, artichoke, spinach, broccoli and green beans.

Boost your iron levels now. Don’t wait until you’re sick and tired of being sick and tired.

– Karen Bowen is a professional health and nutrition consultant. She can be reached by e-mail at karen_bowen@yahoo.com.