@LarissaW, here is the other thing I was mentioning about iron absorption. Sorry it took me a while to get to this…
For runners who have an iron deficiency, there is an additional problem because the release of the hormone hepcidin can be triggered from exercise-induced inflammation.
As you may already know, hepcidin is the regulator of iron metabolism. And when hepcidin levels are higher, iron absorption is decreased.
(This link may be behind a paywall, I am not sure. You can try it. But I put the key points of the entire article in the text below.)
Researchers found that inflammation and hepcidin levels significantly increased three hours after each running session, though the levels were highest following the afternoon runs, since hepcidin levels naturally rise during the afternoon hours.
They also discovered iron was best absorbed in the morning right after exercise, before hepcidin hit its high point.
In fact, when runners consumed iron within 30 minutes following their 90-minute morning run, they absorbed about 40 percent more of the mineral than when they consumed iron after an afternoon run. The morning runners also absorbed the mineral better than those who took iron in the morning, but ran later in the day.
The wiki is short and gives a very good description of what hepcidin does…
And if you want the more sciencey info on it, here is one that tells you the same thing. Same thing as above, but with more details.
And the final part is this, which we’ve already discussed, but the fact that vitamin C improves iron absorption.
So the quick and easy thing to say - you can improve your iron absorption by taking it right after you run in the morning, and also taking it with a big glass of orange juice (carbs too!! 
), right after you finish!
)