Question

How long until I see effects of iron supplementation?

I’m a 52-year-old male and my running performance has been are off by about three minutes; it’s
twice that for a half-marathon. My doctor recently diagnosed low iron levels and prescribed a daily iron
supplement. How quickly should I see a change?
John Mailey, Phoenix, AZ

[Editor’s note: Hemoglobin resides in red blood cells, enabling them to carry and deliver oxygen to muscles and other tissues. Iron is an important component of hemoglobin and of muscle cells. Less than 20% of nonheme iron, the type found in non-animal-product foods, is absorbed into the body when consumed. Nonheme iron is absorbed better when taken with animal protein and vitamin C. Heme iron, the type found in animal products, is absorbed much better by the body.]