Why Your Iron Supplements Aren't Working

Last episode was about understanding the problem. This one is about what to actually do about it.

A lot of women come to me having tried iron supplements for months, sometimes much longer, and their ferritin hasn't moved, or it improves and then drops straight back down as soon as they stop. The assumption is usually that they need a higher dose or a different brand. But rebuilding iron requires strategy around food, supplement form, timing, and what's happening in the gut. Most women who struggle aren't not seeing changes because they aren't trying. They're missing one or more of these variables.

This episode covers all of it.

This week's question comes from a listener on the difference between shyness and social anxiety in children. And my recco is a brand I've been using for years - Chief Nutrition's protein powders, which I use personally and with my kids. (Use the code KATEHOLM10 for 10% off)

In this episode:

• Why the form of iron you eat matters as much as how much you eat

• The meat factor - the under appreciated absorption trick

• Vitamin C as your most practical tool for non-heme iron absorption

• The inhibitors most people don't know about, including why spinach isn't the iron hero you've been told it is

• Supplement forms compared and what to avoid

• Iron infusions - when oral iron isn't enough, and my own experience with them

• Why taking iron every other day might actually get your ferritin moving faster

• The gut piece - and why it's getting its own full episode

The free download

I've put together a free iron and food combinations guide - how much iron is in specific foods, and practical meal combinations that incorporate the absorption principles from this episode. Not because I want you tracking every milligram, but to give you a practical reference point. Grab it below.

Links mentioned:

• ⁠Free iron download⁠

• ⁠In My Clinical Opinion⁠

• ⁠Book a 1:1 consult⁠

• ⁠Chief Nutrition⁠ - use code KATEHOLM10 for 10% off

References:

1. Barney DE et al. Prolonged exercise increases hepcidin and decreases iron absorption in trained athletes. Journal of Nutrition. 2022;152(9):2100-2108.

2. Christides T, Fairweather-Tait S. Inhibitory effects of iron absorption inhibitors and enhancers on haem and non-haem iron. British Journal of Nutrition. 2010;103(6):843-849.

3. Coplin M et al. Tolerability of iron: a comparison of bis-glycino iron II and ferrous sulfate. Clinical Therapeutics. 1991;13(5):606-612.

4. Da Silva Lopes K et al. Nutrition-specific interventions for preventing and controlling anaemia throughout the life cycle. Cochrane Database of Systematic Reviews. 2021;Issue 9.

5. Dignass A et al. How to manage iron deficiency in inflammatory bowel disease. Journal of Crohn's and Colitis. 2018;12(6):748-755.

6. Hallberg L et al. Phytates and the inhibitory effect of bran on iron absorption. American Journal of Clinical Nutrition. 1987;45(5):988-996.

7. Hallberg L et al. The role of vitamin C in iron absorption. International Journal for Vitamin and Nutrition Research Supplement. 1989;30:103-108.

8. Hurrell R, Egli I. Iron bioavailability and dietary reference values. American Journal of Clinical Nutrition. 2010;91(5):1461S-1467S.

9. Litton E et al. Safety and efficacy of intravenous iron therapy in reducing requirement for allogeneic blood transfusion. British Medical Journal. 2013;347:f4822.

10. Lynch SR. The effect of calcium on iron absorption. Nutrition Research Reviews. 2000;13(2):141-158.

11. McCormick R et al. Refuelling with carbohydrate after morning exercise does not alter the afternoon iron absorption response. Journal of Science and Medicine in Sport. 2020;23(9):847-852.

12. Milman N et al. Ferrous bisglycinate 25mg iron is as effective as ferrous sulfate 50mg iron in the prophylaxis of iron deficiency and anaemia during pregnancy. Journal of Perinatal Medicine. 2014;42(2):197-206.

13. Moretti D et al. Oral iron supplements increase hepcidin and decrease iron absorption from daily or twice-daily doses in iron-depleted young women. Blood. 2015;126(17):1981-1989.

14. Moretti D et al. Increasing iron absorption from oral supplements given on alternate days and as single morning doses in iron-depleted women. The Lancet Haematology. 2017;4(11):e524-e533.

15. Name JJ et al. Iron bisglycinate chelate and polymaltose iron for the treatment of iron deficiency anaemia. Current Pediatric Reviews. 2018;14(4):261-268.

16. Nemeth E, Ganz T. The role of hepcidin in iron metabolism. Acta Haematologica. 2009;122(2-3):78-86.

17. Pizarro F et al. Iron bis-glycine chelate competes for the nonheme-iron absorption pathway. American Journal of Clinical Nutrition. 2002;76(3):577-581.

18. Tolkien Z et al. Ferrous sulfate supplementation causes significant gastrointestinal side-effects in adults: a systematic review and meta-analysis. PLOS ONE. 2015;10(2):e0117383.

19. Van Swelm RP et al. The multifaceted role of iron in renal health and disease. Nature Reviews Nephrology. 2020;16(2):77-98.

20. Vaucher P et al. Effect of iron supplementation on fatigue in nonanemic menstruating women with low ferritin. Canadian Medical Association Journal. 2012;184(11):1247-1254.

21. Verdon F et al. Iron supplementation for unexplained fatigue in non-anaemic women. British Medical Journal. 2003;326(7399):1124.

22. World Health Organization. WHO recommendations on antenatal care for a positive pregnancy experience. Geneva: WHO. 2016.

23. Zimmermann MB, Hurrell RF. Nutritional iron deficiency. The Lancet. 2007;370(9586):511-520.

This episode is for educational purposes and does not replace individualised medical or naturopathic advice. Always seek assessment from a qualified health professional for your specific situation.

New here? Find me on Instagram (@kate__holm) or at kateholm.com. Thanks for listening!