While active, childbearing age women are most likely to have low iron stores, he notes, "Men are not safe, especially if they don't eat meat and have a high level of physical activity." An estimated 15% of male long distance runners have low iron stores. Beard and other experts say it's advisable for people in these groups to have a yearly blood test to check blood iron reserves. If iron levels are low, talk with a physician to see if the deficiency should be corrected by modifying your diet or by taking supplements. In general, it's better to undo the problem by adding more iron-rich foods to the diet, because iron supplements can have serious shortcomings.