How to Boost Magnesium Absorption
You’ve done your research, bought a magnesium supplement, and now it’s as simple as remembering to take it every day - no? Well, yes, taking it is the most important step, but what if there were a few simple tips you could follow to increase your magnesium absorption? Read on to discover how to boost magnesium absorption, what interferes with it, and how you can maximise your supplement for the best effects.
Why take magnesium?
Magnesium is used by hundreds of different enzymes in your body. It’s essential for [1]:
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Energy production.
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Normal muscle function.
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Manufacturing hormones and neurotransmitters.
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Blood sugar regulation.
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Mental wellbeing.
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Electrolyte balance.
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Protein manufacture.
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Healthy bones and teeth.
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Normal cell division.
Because magnesium has so many roles to play, signs of deficiency vary from person to person. Common indicators of low magnesium include muscle cramps and twitches, low energy, anxiety and depression, nausea, high blood pressure, and constipation.
Where is magnesium absorbed?
Magnesium is mainly absorbed in the ileum (the last part of the small intestine), and a small amount is absorbed in the large intestine [2]. Up to 76% of the magnesium we take in is absorbed, the rest is excreted via the kidneys and bowel [2]. This absorption rate is tightly controlled by a hormonal feedback loop that detects how much you need.
Does coffee block magnesium absorption?
Unfortunately, yes! Caffeine in tea and coffee can irritate the digestive tract which may impair magnesium absorption, and it also increases magnesium excretion by making you pee more [3].
Alcohol has the same diuretic effect [4]. Both caffeine and alcohol stimulate urine production in the kidneys which increases the loss of electrolyte minerals including magnesium.
6 ways to boost magnesium absorption
If you’re taking a magnesium supplement, you’ll want to get as much from it as you can. Here are 6 steps you can take to boost your magnesium absorption and retention.
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Minimise free sugars. Eating a lot of free and added sugars in sweets, biscuits, cakes, fruit juices, and syrups, means your body has to work harder to metabolise all the glucose. When your kidneys metabolise and excrete excess glucose, magnesium can be lost in the process [5].
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Take calcium supplements separately. Calcium and magnesium compete for absorption in the gut and for transportation into cells [6] so it’s wise to take any extra calcium at a different time of day, away from your magnesium supplement.
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Take high-dose zinc supplements separately. High amounts of supplementary zinc are known to interfere with magnesium absorption and overall magnesium balance [7]. However, there’s no known issue with the 15-25mg of zinc normally used in supplements.
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Avoid fizzy drinks. Carbonated drinks contain phosphate in the form of phosphoric acid. It’s used to provide a tangy flavour and stop the growth of mould and bacteria. Phosphate can bind to magnesium in the intestines and block its absorption [8].
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Minimise tea, coffee, and alcohol. Caffeine and alcohol increase magnesium excretion via the kidneys.
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Soak nuts, seeds, legumes, and wholegrains before eating. The outer skin of nuts, seeds, and wholegrains contain phytates, the plant storage form of phosphate. Phytates can bind to minerals like magnesium, iron, and zinc, in the intestines and impair their absorption.
We can’t escape phytates completely but if you want to enhance your magnesium absorption, try soaking these foods in water for a few hours (or overnight) before cooking and eating. Soaking helps to lower the phytate content so there’s less available to bind to magnesium.
Magnesium and the gut microbiome
One more way to enhance magnesium absorption is to nurture your gut microbiome. Research shows that several types of bacteria including strains of Lactobacillus and Bacillus influence mineral absorption in the gut [10].
These bacteria produce phytase enzymes that help you breakdown phytic acid in the digestive tract and access magnesium and other minerals [10]. They also maintain a low pH environment in the gut. This increases the solubility of minerals making them more accessible for absorption. When the gut microbiome is disturbed and in a state of dysbiosis, mineral absorption is impaired [10].
A healthy, diverse microbiome gives your gut the best chance to absorb magnesium and other essential nutrients. For top tips on how to support your microbiome read The Power of Prebiotics: Nurturing Your Gut for Optimal Health.
Do medications interfere with magnesium absorption?
Yes, a significant number of medications either interfere with magnesium absorption, increase your magnesium requirements, or are affected by magnesium supplements [9]. These include:
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Bisphosphonates
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Blood pressure medications
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Corticosteroids
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Proton-pump inhibitors
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Diuretics
We recommend you consult your healthcare practitioner before using a magnesium supplement alongside prescription medications.
We hope you feel inspired to make the most of your magnesium supplements! You can view our full range of magnesium products in the store and check out our popular Magnesium Bundle here.
You might also enjoy reading
How to Maintain Normal Blood Sugar Balance
The Role and Health Benefits of Magnesium Glycinate

References
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Nutraceuticals Group, 2024. Full list of EFSA health claims [online] Available at https://nutraceuticalsgroup.com/uk/full-list-of- efsa-health-claims/
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Jahnen-Dechent, W., & Ketteler, M. 2012. Magnesium basics. Clinical Kidney Journal, 5(Suppl 1), i3. https://doi.org/10.1093/ndtplus/sfr163
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Bergman, E. A., Massey, L. K., Wise, K. J., & Sherrard, D. J. 1990. Effects of dietary caffeine on renal handling of minerals in adult women. Life Sciences, 47(6), 557-564. https://doi.org/10.1016/0024-3205(90)90616-Y
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Romani A. M. 2008. Magnesium homeostasis and alcohol consumption. Magnesium Research, 21(4), 197–204.
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Barbagallo, M., & Dominguez, L. J. 2015. Magnesium and type 2 diabetes. World Journal of Diabetes, 6(10), 1152. https://doi.org/10.4239/wjd.v6.i10.1152
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Dai, Q., Shrubsole, M. J., Ness, R. M., Schlundt, D., Cai, Q., Smalley, W. E., Li, M., Shyr, Y., & Zheng, W. 2007. The relation of magnesium and calcium intakes and a genetic polymorphism in the magnesium transporter to colorectal neoplasia risk1. The American Journal of Clinical Nutrition, 86(3), 743. https://doi.org/10.1093/ajcn/86.3.743
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Spencer, H., Norris, C., & Williams, D. 1994. Inhibitory effects of zinc on magnesium balance and magnesium absorption in man. Journal of the American College of Nutrition, 13(5), 479–484. https://doi.org/10.1080/07315724.1994.10718438
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Brink, E. J., Beynen, A. C., Dekker, P. R., Van Beresteijn, E. C., & Van der Meer, R. 1992. Interaction of Calcium and Phosphate Decreases Ileal Magnesium Solubility and Apparent Magnesium Absorption in Rats. The Journal of Nutrition, 122(3), 580-586. https://doi.org/10.1093/jn/122.3.580
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Gröber, U. 2019. Magnesium and Drugs. International Journal of Molecular Sciences, 20(9), 2094. https://doi.org/10.3390/ijms20092094
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Varvara, R., & Vodnar, D. C. 2024. Probiotic-driven advancement: Exploring the intricacies of mineral absorption in the human body. Food Chemistry: X, 21, 101067. https://doi.org/10.1016/j.fochx.2023.101067