Back in the days of black and white television, a popular commercial cautioned viewers about the dangers of iron-poor blood. While those ads trumpeting the debilitating fatigue of iron deficiency have disappeared from our colorized video world, medical researchers now recognize that many of us, in fact, are hampered by an iron shortage. What those old ads missed: a lack of iron can slow you down mentally and physically even before it shows up in your blood.

A Woman's Dilemma: Hidden Deficiencies
Experts estimate that one in 10 American women are low in iron but many haven't become so deficient that they are aware of their shortage. In other countries, up to eight in 10 women run short on iron. While researchers once believed that iron deficiency was only serious if it was drastic enough to cause anemia (what used to be called "tired blood"), studies now show that even mild deficiencies can compromise health.

Worldwide, public health experts believe that the lives of about 2 billion people are affected by iron deficiency. Most of these people are women, who lose blood on a monthly basis during their childbearing years. Men are generally not low in iron.
Iron is necessary for the formation of red blood cells-particularly the creation of hemoglobin, the reddish pigment in these cells that enables them to deliver oxygen to muscles and other bodily tissues. If you are very low in iron, the resulting anemia leaves you feeling fatigued.

Your body stashes iron not only in your blood cells, but in your liver and other tissues as well. When you don't consume enough iron, first your liver stores decrease, then your tissue supplies disappear and, finally, your blood runs low and you develop anemia.
Early on in the iron-depletion process, a low iron count won't make your daily activities more difficult. Cornell University researchers found, in experiments on women who were mildly depleted, that taking or not taking iron supplements had no effect on how these women felt while exercising.

" Supplementation makes no difference in exercise-training improvements in women with low iron storage who are not yet tissue-iron deficient or anemic," says Thomas Brownlie, one of the Cornell researchers.

Supplementing Your Supply
Even in the beginning stages of iron deficiency, however, experts still believe you should take supplements: an uncorrected iron shortage can mean serious problems lurk ahead (American Journal of Clinical Nutrition 5/04).
For that reason, the next time you visit your healthcare practitioner you should request a serum transferrin receptor concentration test, which can detect an early iron shortage. (Don't start taking iron supplements without consulting a knowledgeable medical professional.)

" It would be useful for women who test low for iron but who are not yet anemic to have this test," notes Cornell's Brownlie. "Women found to be tissue-iron deficient will find exercise exceedingly difficult without improving their iron status-which could be achieved by increasing consumption of iron-rich foods or iron supplementation."

Iron-Poor Blood
If you let your iron levels run down so low that it shows up as anemia, not only will you be tired but your thinking may be fogged as well. " Millions of women who are mildly iron deficient must work harder than necessary when exercising or working physically, and they can't reap the benefits of endurance training very easily," says Jere Haas, PhD, one of the researchers involved in these studies and a nutrition professor at Cornell. "As a result, exercise is more difficult so these women are more apt to lose their motivation to exercise."

Meanwhile, researchers at Wake Forest University in North Carolina report that, as you age, anemia can make you more vulnerable to disabilities while weakening your muscles and draining your strength (Journal of the American Geriatric Society 5/04). That type of anemia may be linked to shortages of both iron and vitamin B12.

" Our results suggest that anemia is a risk factor for disability, poor physical function and low muscle strength-all which can threaten the independence of older adults," says Brenda Penninx, PhD, lead researcher. If you are a woman who exercises frequently, cuts calories to lose weight or eats a mostly vegetarian diet, watch out-you may be at high risk for iron depletion.

To steer clear of iron shortages, the Cornell researchers recommend eating lean red meat. If you are a vegetarian, taking vitamin C with meals improves your iron absorption from iron-rich foods like peanuts, whole wheat, brown rice and leafy green vegetables, as does using iron cookware.

Chelated Minerals
When it comes to absorbing supplemental minerals like iron, not all minerals may be created equal. In particular, minerals that are in chelated form are generally believed to be absorbed more efficiently in your digestive system.
The word "chelate" comes from the Greek word for claw. Chelated minerals are chemically implanted into proteins known as peptides. This bound molecular structure mirrors the way minerals are contained in natural whole foods, which have been found to contain their own natural chelates.

Chelated minerals are more well-suited to your digestive tract. A key advantage of chelated formulations is their stability after you swallow them. Many other forms of supplemental minerals-which are often combined with inorganic salts or organic acids-may be broken down prematurely in the digestive tract, leading to poor absorption and a stomachache.

Chelates, however, maintain their structure sufficiently to reach the spot in the digestive tract where they are most efficiently taken into the bloodstream. Once there, the body's digestive enzymes dismember the proteins and convert the minerals into absorbable form.

Getting enough iron and other minerals is not that difficult a task-it's just one that is too often overlooked. But if you pride yourself on your iron will or iron constitution, or just seek to iron out a few of the kinks in your health, you may need to significantly pump up your iron.