Help! My Iron Supplement Is Making Me Constipated
Taking an iron supplement may be necessary to replace low iron stores in the body that cannot be done with dietary changes. Iron is needed because it is part of blood cells, which carry oxygen throughout the body. Low iron levels may occur more frequently in certain groups of people such as teenage girls and women with heavy periods, infants, and people with certain conditions (cancer, gastrointestinal conditions, heart failure).
What are common side effects of taking iron supplements?
Iron supplements most often affect the gastrointestinal (GI) tract and cause nausea, vomiting, constipation, diarrhea, gas, or upset stomach. Tarry, black stools often occur as well.
Other side effects include a metallic taste in the mouth and staining of the teeth, particularly with liquid products.
How should I take my iron supplement?
Take your iron medication at least 30 minutes before a meal for the best absorption. Taking it with orange juice or other vitamin C products may also help to absorb it better. If you begin to have GI effects, you may take it with a small amount of food. Avoid taking iron with milk or other dairy products, high fiber foods, or caffeine.
Iron supplements may interact with certain medications so always check with your pharmacist before taking them together. It is best to take iron products at least 2 hours before other medications. Do not take iron supplements together with calcium or antacid products.
So many products are available, which one should I take?
If your doctor recommends that you take an iron supplement, it is best to ask your doctor or pharmacist for specific recommendations based on your health.
Generally, the ferrous products are available over the counter and are affordable. These products include ferrous sulfate, ferrous gluconate, and ferrous fumarate. However, these products are reported to cause GI side effects. Slow-release ferrous products (e.g., Slow Fe) are available and by releasing the iron over a longer period, the GI effects may be reduced.
Ferric iron supplements are reported to cause less side effects, but they are not absorbed as well and are more expensive. Examples include:
- iron protein succinylate (Ferretts IPS® liquid)
- polymaltose complex (Accrufer®; note this is only available as a prescription product)
- carbonyl iron (Ferra Cap®, Feosol® natural release)
Summary
Ask your pharmacist to help you select the best iron product for your needs. If you have side effects, ask your doctor or pharmacist for help to select another product or adjust how you are taking it to lessen these effects.