It's January – time to make New Year's resolutions! More than two-thirds of Americans who make resolutions choose to focus on health and fitness, which probably means a lot of us are planning to exercise more in the new year. 

After pumping more iron at the gym, we hope you'll find out if you need to pump up your body's internal iron stores as well. Iron deficiency is common, especially in pre-menopausal women who lose blood during menstruation. In fact, according to the National Heart, Lung and Blood Institute, 20% of women under 50 are iron deficient. 

If you're ramping up your exercise regimen, it's important to know that the rate is even higher among female athletes. "Anywhere from 33 percent to 80 percent of female athletes are iron deficient," says Thomas DeLoughery, M.D., M.A.C.P., professor of medicine in the Divisions of Hematology/Oncology and Laboratory Medicine at OHSU. 

Why is iron so important?  

Your body uses iron to make hemoglobin, the protein in your blood that carries oxygen to all your tissues and muscles. If you are iron deficient, your whole body can't get the amount of oxygen it needs. 

Furthermore, even mild iron deficiency can be harmful. "The biggest sign is fatigue," says Dr. DeLoughery. "This can be seen even with a modestly low iron level." 

Did you know iron deficiency can also cause: 

• Restless leg syndrome 
• Hair loss 
• Pulmonary hypertension (a type of high blood pressure that affects your lungs and heart) 
• Shortness of breath 
• Cognition problems 
• Cravings for ice

For athletes, iron deficiency can quickly impact stamina and endurance, strength, and cold tolerance. 

If you are experiencing any of these symptoms, talk to your health care provider. There are simple blood tests that can help your provider determine if your iron stores are low. 

Treating iron deficiency 

The good news is that iron deficiency is extremely treatable! Both diet and supplements can play a role. 

"We don't know exactly why, but iron from meat sources is ten times better absorbed than iron from plant sources," says Dr. DeLoughery. For example, a serving of roast chicken and a serving of whole grain bread contain similar amounts of iron, but three times as much will be absorbed into the bloodstream from the chicken as from the bread. The best dietary source of iron for those who eat it is red meat, like lean steak. A serving has 5.5mg of iron, 20% of which can be absorbed. 

For vegetarians, the best dietary sources are tofu and legumes. Dark, leafy greens, like spinach, contain a lot of iron, but our bodies absorb just 2% of it. 

If your provider finds that you are iron deficient, oral iron supplements are a great option. "Oral iron pills can be very effective, especially in young women," says Dr. DeLoughery. Two types, ferrous sulfate and ferrous gluconate (which is often easier on the stomach) are available over-the-counter.  

"Take one iron pill per day containing at least 18mg of elemental iron," Dr. DeLoughery says. He recommends taking the supplement with an iron-rich meal which helps improve absorption. 

If you are working to pump up your iron levels, there are several ways beyond eating meat that will help you better absorb the iron in supplements. First, calcium and fiber can block iron absorption, so don't take your iron supplement with a meal rich in these elements. Vitamin C, on the other hand, aids in iron absorption. 

"You should avoid coffee and especially tea within a few hours of taking iron supplements," says Dr. DeLoughery. Both decrease iron absorption, tea by as much as 80 percent, and the effects last up to four hours after drinking. 

It can take a month or longer to build up iron stores. For his patients, Dr. DeLoughery repeats blood tests after about a month to check on progress. 

For those of you who are pumping more iron in 2017, we wish you the best of luck in achieving your health and fitness goals! We hope you'll keep an eye out for symptoms of iron deficiency too. After all, maintaining your iron stores is an easy way to boost your stamina and strength.