Although iron deficiency may be a concern, a word of caution about taking too much (such as iron supplements if you (the general "you") are not a menstruating female): you can ingest too much iron. If you are low in iron, eat iron-rich foods (eggs, spinach, beans/lentils, fortified cereals), rather than take supplements.

Easy non-scientific way to check if you're low: pull down your lower eyelid and check the color of your skin of the uncovered lid. A pale red suggests you should be checked for anemia.