Do you recommend/prescribe iron to any of your patients? Are they iron deficient? Or maybe they have low ferritin levels and benefit from iron supplementation? Regardless, you should know the differences between the various iron formulations.

Remember, you are dosing based off the ELEMENTAL IRON dosage, not the actual dosage of the iron supplement itself. Only a fraction of iron supplements contain elemental iron, and that is what is important.

Standard dosing is 50-60mg of elemental iron 1-2x daily for 3 months in those with iron deficiency anemia, but recent research indicates that dosing every other day carries with it the same clinical efficacy without the bothersome side effects.

Iron supplements:

Ferrous Sulfate:  Standard dose of 325mg and it contains 65mg of elemental iron. The downside with ferrous sulfate is that it is notorious for causing gastrointestinal symptoms such as stomach cramping, constipation, and nausea.

Ferrous gluconate: Standard dose of 325mg and it contains only 35mg of elemental iron. It is generally better tolerated than the ferrous sulfate in terms of gastrointestinal symptoms.

Ferrous fumarate: Standard dose of 325mg and contains the most elemental iron at 108mg. The only issue is that the bioavailability of the iron is low, and it carries with it significant gastrointestinal side effects.

Ferrous bisglycinate: Standard dose is 25mg and it contains 25mg of elemental iron. It essentially is a 1:1 ratio so it makes dosing simple since the elemental iron amount is what is important. Other benefits include that it is highly bioavailable and has the lower gastrointestinal side effect profile out of all the iron supplements. This is my GO-TO iron supplement I recommend to patients!