Which iron salt is better

Oral iron therapy is suitable as first line therapy in patients with iron deficiency or iron deficiency anemia. When your doctor advises you to start taking iron supplements, it can be a challenge to choose the right one with so many options on the market.

There are different types of iron found in iron supplements. Here's what you need to know about them.

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Iron supplements come in different forms either as solid or liquid preparations. Many different iron tablets and tonics can be bought over-the-counter (without a prescription) but not all of these have enough iron in them to make a difference.

Ferrous iron such as ferrous sulfate ferrous fumarate and ferrous gluconate are the most commonly recommended and prescribed forms of iron.19

All types of supplemental iron help to increase red blood cell production but vary in cost and amounts of elemental iron. Each form has a different amount of iron. Dosage is noted either as the amount of iron or the percentage of iron.

Read the label closely. For example, 325 mg of ferrous sulfate contains only 65 mg of elemental iron.


When choosing an iron supplement, read the label to see what type of iron and the concentration of elemental iron. Elemental iron is the amount of active iron available for absorption.

Speaking of absorption, an iron supplement is usually best taken on an empty stomach (if tolerated) or with foods that are high in vitamin C to enhance iron absorption.

On the other hand, you should avoid taking certain foods and drinks while taking iron supplements. Tea, coffee, milk, antacids or calcium supplements can decrease the amount of iron absorbed, so these foods should be avoided for an hour before and after taking a supplement.


Not all iron salts contain the same amounts of iron per dose. This means that different iron salts will require different dosing regimens in order to meet your doctor's recommendation.

Though high-dose supplements are available, your body absorbs iron better when taken in smaller doses spread throughout the day. Look for supplements that allow you to take in smaller doses a day that, in total, meet your recommended daily dosage.


It is normal to notice dark coloured bowel movements when you are taking iron. Sometimes iron supplements can cause indigestion, constipation diarrhea or nausea.21 The risk of these side effects increases with higher dosages. These common side effect may plague up to 20% of patients and limit compliance with iron therapy.

Recent evidence suggests that lower doses of iron are preferred to high doses in non-urgent cases so as to avoid iron overload, tolerance issues and impacting compliance. Your doctor may recommend that you start with a smaller dose of iron and gradually increase the dose to minimize side effects. Slow-release (enteric-coated) forms of iron are usually not recommended, though they may have fewer side effects because they aren't absorbed as well by the body.22

Some forms of iron are better absorbed than others and therefore the dose prescribed depends on the type of iron. Ferrous gluconate, in some clinical studies, have shown that it is most easily absorbed of all ferrous salts and with less gastrointestinal intolerance the ferrous sulfate. Sangobion (P&G Health) contains clinically proven ferrous gluconate formulated to help the body absorb iron more effectively and to reduce gastric side effects and constipation, with proper diet and exercise. It is a blood health builder as it includes other key nutrients such as Vit B6, B12, Folic Acid, Manganese and Vit C to enhance absorption.


Normally, it may take from a week to a month (after you start your iron supplement) before you start to feel better. On the optimal duration of iron supplementation, most experts recommend continuing iron supplementation for three months after normalization of haemoglobin in order to replenish iron stores.

Compliance is a crucial part of iron supplementation and treating iron deficiency and anemia, so look for a supplement with a dosing schedule that fits your lifestyle. Speak to your doctor or pharmacist about your needs and which supplement is right for you.

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  • 19 Santiago, Palacios. Ferrous versus Ferric Oral Iron Formulations for the Treatment of Iron Deficiency: A Clinical Overview. The ScientificWorld Journal. Volume 2012, Article ID 846824, 5 pages. doi:10.1100/2012/846824

  • 21 A patient's guide to oral iron supplements. Society for the Advancement of Blood Management Inc. Dec 2018. www.iron.sabm.org.

  • 22 Callender, Sheila T. M.D., F.R.C.P. Quick and Slow release Iron: A double blind trial with a single daily dose regimen. British Medical Journal 1969, 4, 531-532.

If symptoms persist, consult your doctor. ASC Ref. No. P045N071221SS

If symptoms persist, consult your doctor. ASC Reference No.: P170P062921SS