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Which iron supplement should I take and how often?

by Anja Bauer.

When it comes to iron supplementation, choosing the right form and frequency can significantly impact its effectiveness and tolerability.

Iron is a vital mineral responsible for various functions in the body, such as oxygen transport, energy production, and DNA synthesis.

However, many people, particularly women, pregnant individuals, athletes and vegetarians, and those with certain medical conditions like anemia, may struggle to maintain adequate iron levels through diet alone.

iron supplelents

Here's a breakdown of some common forms of iron supplement and how often they should be taken:

  1. Form of Iron Supplement:

  • Ferrous Sulfate: This is one of the most common and inexpensive forms of iron supplements available. It contains a high concentration of elemental iron, however the iron has only 10-15% bioavalability. The 85% that is not absorbed in the gut often causes gastrointestinal side effects like constipation, nausea, and stomach upset, and can have a detrimental effect on the intestinal microbiome.

  • Ferrous Gluconate: Compared to ferrous sulfate, ferrous gluconate tends to be gentler on the stomach and may cause fewer side effects. It contains less elemental iron per dose but is still effective in replenishing iron stores. This form is often recommended for individuals who experience digestive issues with other iron supplements.

  • Ferrous Fumarate: Similar to ferrous sulfate, ferrous fumarate provides a high concentration of elemental iron. It may cause fewer gastrointestinal side effects than ferrous sulfate but more than ferrous gluconate. It's a suitable option for individuals who need a potent iron supplement and can tolerate moderate stomach discomfort.

  • Ferrous Bisglycinate: Although this form contains a lesser amount of iron, it is the most bioavailble, meaning that most of the iron in this suppplement is absobed into the blood and it has the least gastrointesinal side effects. For this reason, ferrous bisglycinate, (iron bisglycinate), is perhaps the best form of iron supplement to take.

2. Frequency:

  • The frequency of iron supplementation depends on the individual's iron status, the severity of deficiency, and the type of supplement used.

  • For mild iron deficiency, typically 25 mg of elemental iron per day is recommended. This can be achieved with one to two doses of most iron supplements.

  • For moderate to severe deficiency, higher doses may be necessary initially, but these should be adjusted based on blood tests and under medical supervision. Higher doses are best absorbed if taken every second day.

  • Iron supplements are best taken in the morning when blood iron levels are lowest to enhance absorbtion. Taking iron supplements with vitamin C can also improve absorption.

  • Once iron levels have been restored to normal, a maintenance dose may be prescribed to prevent relapse. This usually involves taking a lower dose of iron supplements less frequently, such as every other day or a few times per week.

In conclusion, the best form of iron supplement depends on individual tolerance and preference, with ferrous bisglycinate often being favored for its milder side effects.

The frequency of supplementation should be tailored to the individual's needs, with regular monitoring of iron levels to ensure efficacy and safety.

Consulting a healthcare professional is advisable to determine the most suitable iron supplement regimen for specific health conditions and circumstances.

Anja Bauer is our resident Naturopath-Nutritionist


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