From the Guidelines
Tea consumption should be avoided within at least 1 hour after taking iron supplements to minimize inhibition of iron absorption. According to a recent clinical practice update on management of iron deficiency anemia 1, tea and coffee are powerful inhibitors of iron absorption. The study suggests that certain dietary manipulations may improve iron absorption, but tea and coffee should not be consumed within an hour after taking iron. Some key points to consider when taking iron supplements include:
- Taking iron with 80 mg ascorbic acid on an empty stomach may improve iron absorption 1
- Vitamin C improves absorption by forming a chelate with iron that prevents the formation of insoluble iron compounds and by reducing ferric to ferrous iron 1
- Ferrous iron salts (ferrous sulfate, ferrous fumarate, and ferrous gluconate) are a reasonable choice to start with because they are often the least expensive 1
- Side effects are common with oral iron, including constipation, diarrhea, and nausea 1 It is essential to note that the timing of tea consumption matters, as tea contains tannins that bind to iron molecules, forming insoluble compounds that the body cannot absorb. This effect is particularly important for people with iron deficiency anemia or those at risk of low iron levels. If you enjoy tea regularly, consider shifting your tea consumption to between meals rather than eliminating it completely from your diet.
From the Research
Tea and Iron Interaction
- Tea is known to contain polyphenols, which can reduce iron absorption from the diet 2
- Polyphenols in tea can bind to iron and form insoluble complexes, making it less available for absorption in the gut 2
- However, the exact mechanism of tea's effect on iron absorption is not fully understood and may depend on various factors such as the type of tea, amount consumed, and individual characteristics
Iron Absorption and Dietary Factors
- Iron absorption can be enhanced by components such as meat proteins and organic acids, while phytate, calcium, and polyphenols can reduce iron absorption 2
- Haem iron from animal sources has higher bioavailability than non-haem iron from plant sources 2
- Iron deficiency can be addressed through various solutions, including iron supplements, intravenous iron, and iron-fortified foods 2, 3
Oral Iron Supplementation
- Oral iron supplementation is often the first-line treatment for iron deficiency, but there is no consensus on the optimal formulation or dosing strategy 4, 5, 3
- Different oral iron formulations, such as ferrous and ferric forms, have varying efficacy and tolerability profiles 4, 5, 6
- Novel iron formulations, such as lipophilic iron donors and nanoparticle-encapsulated iron, have been developed to improve efficacy and reduce side effects 4