Iron Supplements: How To Optimize Absorption?
Iron deficiency is the most common deficiency in the world(1). Your physician will prescribe iron supplement based on laboratory results and clinical examination. There are in the market many types of iron salts, some are combined with vitamins like vitamin C or vitamin B6, others are better absorbed or more tolerated. Whatever the brand you are prescribed, some recommendations are common. Let’s get the best out of your treatment!
Note that these recommendations are general, if you are taking chronic medications, or have chronic diseases, you may need to refer to your health care professional for a patient centered approach.
Avoid antacids and PPIs
While abdominal cramps and nausea are common side effects of iron supplementation, taking antacids and PPI to relieve these particular side effects, is not recommended and will not treat your symptoms. Increasing absorption, helps decreasing side effects!
In fact, stomach acidity enhances the solubility of ferric iron and thus its absorption in the small intestine, where the majority of nutrients are being absorbed. Taking over the counter medications, antacids, PPis (proton pump inhibitors) and anti-H2 (Cimetidine) decreases the degree of the acidity by respectively neutralizing the acids present in your gastrointestinal system, and by preventing its production(2).
However if you’re taking PPIs for the treatment of a chronic condition like GERD, your doctor will monitor your iron treatment efficacy through regular blood test. Depending on the case other measures could be taken like administering an intravenous iron, increasing the dose or prolonging the duration of treatment.(3,4)
Effect of Vitamin C
As it was mentioned above acidity protects the solubility of iron and help its absorption. Ascorbic acid( Vitamin C) and citric acid protect ferric iron from the diminished acidity in the small intestine where it will be absorbed.(5)
Accordingly taking your pill with a cup of orange juice, or with your Vitamin C supplement can enhance the absorption of iron. Some iron pills contain already a combination of iron salt and ascorbic acid! But studies have failed to support this recommendation.(6)
However vitamin, citric acid and lean meats enhance the absorption of dietary inorganic iron. Inorganic iron comes from vegetable sources (beans, lentils…). In that case it’s always advisable to add lemon juice or other source vitamin C, citric acid or meat proteins to your plate.
Take your pill on empty stomach and avoid some interactions
The best time to take your iron pill is one hour before meals or 2 hours after meal maximum, in other words, on empty stomach. That’s because the level of acidity in your stomach is the highest when you’re not eating. In fact, the food you eat has a capacity to lower the acidity of the gastro intestinal tract, which decreases the absorption of iron.
In addition, some types of food inhibit the iron absorption and must be avoided, like:
- Calcium and calcium containing food (dairy…) inhibit the uptake of iron in the intestines. Subsequently, and in order to enhance calcium absorption, do not schedule the administration of both supplements at the same time of the day.
- Proteins (egg whites, soy protein)
- Zinc supplements
- Legumes and vegetables, fruit, nuts: spinach, chard, beans
- Beverages: Black and herbal tea, coffee, wine(7)
- Some antiretroviral medications (Raltegravir…): iron decrease the absorption of those medication. Always consult your pharmacist or doctor to prevent drug-drug interaction.
In conclusion the best time to take your iron supplements is minimum one hour before meals (empty stomach). You may combine it with your vitamin C supplements or any other vitamin C or citric acid source (orange juices..). Do not forget to schedule your calcium and/or Zinc supplements at different timing from iron pill. Talk to your health care provider if you have any medical condition or if you feel uncomfortable with your treatment.
References
1. WHO | Micronutrient deficiencies [Internet]. WHO. World Health Organization; [cited 2022 Aug 15]. Available from: http://www.who.int/nutrition/topics/ida/en/
2. Vitamin C | The Nutrition Source | Harvard T.H. Chan School of Public Health [Internet]. [cited 2022 Aug 12]. Available from: https://www.hsph.harvard.edu/nutritionsource/vitamin-c/
3. Drug Interactions results – MICROMEDEX [Internet]. [cited 2022 Aug 16]. Available from: https://www.micromedexsolutions.com/micromedex2/librarian/PFDefaultActionId/evidencexpert.ShowDrugInteractionsResults
4. Ajmera AV, Shastri GS, Gajera MJ, Judge TA. Suboptimal response to ferrous sulfate in iron-deficient patients taking omeprazole. Am J Ther. 2012 May;19(3):185–9.
5. Lynch SR, Cook JD. Interaction of vitamin C and iron. Ann N Y Acad Sci. 1980;355:32–44.
6. Li N, Zhao G, Wu W, Zhang M, Liu W, Chen Q, et al. The Efficacy and Safety of Vitamin C for Iron Supplementation in Adult Patients With Iron Deficiency Anemia. JAMA Netw Open. 2020 Nov 2;3(11):e2023644.
7. Alternative Medicine Result Page – In-Depth Answers – Pharmacokinetics – Adme [Internet]. [cited 2022 Aug 16]. Available from: https://www.micromedexsolutions.com/micromedex2/librarian/CS/2403F6/ND_PR/evidencexpert/ND_P/evidencexpert/DUPLICATIONSHIELDSYNC/8DB63F/ND_PG/evidencexpert/ND_B/evidencexpert/ND_AppProduct/evidencexpert/ND_T/evidencexpert/PFActionId/evidencexpert.IntermediateToDocumentLink?docId=44&contentSetId=137&title=IRON&servicesTitle=IRON#