Iron carries oxygen around in the blood. So, if you have more "good" iron, you will have more
oxygen in your blood! Boy, that would be great! More oxygen = more energy. More energy = more stuff gets done. Okay, you get the picture. Look for: elemental iron in your supplement.
Ferrous gluconate has much less chance of constipation (that's good). Remember that you should NOT take your iron supplement with your calcium. Calcium will reduce iron absorption. One supplement that I really like is Floravital Iron and Herbs, this is a liquid supplement that tastes like rusty prune juice, but boy does it work. Taken as directed, it can reduce some eye floaters, dizziness, headaches, constipation, and low energy to name a few!