Can I Drink Coffee While Taking Iron Supplements?

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<p>If you take an iron supplement with your morning coffee or tea, you may be reducing how much iron your body absorbs. But that doesn’t necessarily mean your caffeine habit is sabotaging your iron levels.</p>
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<p>Yes, coffee and tea can interfere with iron absorption under certain circumstances. But it’s largely because of compounds called polyphenols, not the caffeine itself. For many people, this interaction is unlikely to cause problems. But if you’re taking an iron supplement due to low iron levels, or you’re at risk of developing low iron, paying attention to when you drink these beverages may be more important.</p>
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<h2 class="wp-block-heading">It’s Not the Caffeine, It’s Polyphenols</h2>
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<p>Coffee and tea don’t interfere with iron because of caffeine. Other compounds called polyphenols are primarily to blame, says <a href="https://www.linkedin.com/in/mgblyumin">Michael Blyumin</a>, PharmD, a clinical ambulatory care pharmacist at Stanford Health Care. </p>
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<p><a href="https://www.mdpi.com/1420-3049/29/10/2231">Polyphenols</a> are plant chemicals with <a href="https://medlineplus.gov/antioxidants.html">antioxidant</a> and anti-inflammatory properties that help protect cells from damage. The major polyphenols in coffee are chlorogenic acids, and the major polyphenols in teas are tannins. Polyphenols bind to certain types of iron in your gut, forming a larger iron-polyphenol molecule that your body can’t absorb as well. Because your body can only absorb iron in a usable, soluble form, less iron gets into your bloodstream. </p>
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<p>Although decaf coffee and teas have less caffeine, they can still contain polyphenols, though the amount may vary. And matcha, a type of green tea, is <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC7231151/">highly concentrated with polyphenols</a>.</p>
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<h2 class="wp-block-heading">Heme or Non-heme: Your Primary Source of Iron Matters</h2>
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<p>Iron comes in two main forms: <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC6567869/">heme and non-heme</a>. Heme iron, found in meat, chicken, and seafood, is mostly unaffected by polyphenols. It’s absorbed through a different pathway. </p>
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<p>Non-heme iron, found in plant foods like lentils, beans, and spinach, is also the form used in most iron supplements. Non-heme iron absorption is <a href="https://www.sciencedirect.com/science/article/pii/S0022316622099254?via%3Dihub">blocked by polyphenols</a> in coffee or tea.</p>
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<p>“Someone who gets most of their iron from animal sources usually doesn’t need to worry as much about timing their coffee or tea intake,” says <a href="https://profiles.mountsinai.org/christopher-anthony-gold">Christopher Gold</a>, DO, an internal medicine physician at Mount Sinai in New York, adding that those with a vegetarian or vegan diet, or who take iron supplements, may need to pay closer attention to timing.</p>
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<h2 class="wp-block-heading">What the Research Shows</h2>
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<p>Research suggests that coffee and tea can reduce non-heme iron absorption. But how much this matters in real life is harder to answer.</p>
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<p>“The real-world impact seems to vary,” says Dr. Gold. Some studies show that drinking coffee or tea decreases iron absorption or bioavailability, while others don’t show a clinically significant effect on iron levels, he says.</p>
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<p>Part of the challenge is that many iron absorption studies are small and short-term. They often look at how much iron is absorbed from one meal or one supplement dose, not whether someone’s iron levels change over months. And while observational studies from the past few years are useful, they often depend on people accurately reporting how much coffee or tea they drink, which is not always reliable.</p>
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<p>Even with those limitations, several studies have found associations between coffee or tea consumption and lower iron absorption or ferritin levels:</p>
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<li>A few older studies found that <a href="https://www.researchgate.net/publication/16793217_Inhibition_of_food_iron_absorption_by_coffee">coffee</a> and <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC1410962/?page=1">tea</a> can reduce iron absorption when consumed with a meal or iron-containing foods. In an older coffee study, larger amounts of coffee reduced absorption, whereas drinking coffee 1 hour before a meal did not appear to reduce iron absorption to the same extent.</li>
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<li>A 2023 Japanese study of nearly 10,500 adults found that <a href="https://pubmed.ncbi.nlm.nih.gov/37637954/">higher green tea and coffee intake was linked to lower ferritin</a> levels in men and postmenopausal women. In premenopausal women, only green tea consumption was associated with lower ferritin. <a href="https://medlineplus.gov/lab-tests/ferritin-blood-test/">Ferritin</a> is a protein that binds to and stores iron in the body.</li>
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<li>A 2023 Korean study of<a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC10040265/"> 4,322 premenopausal women</a> found that coffee intake was linked to lower ferritin levels. And the more coffee participants drank, the lower their ferritin levels tended to be. </li>
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<li>Another <a href="https://onlinelibrary.wiley.com/doi/full/10.1002/ajh.26987">2023 randomized crossover study of 34 women</a> with iron deficiency found that drinking coffee with an iron supplement reduced absorption. </li>
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<li>However, a 2007 French study of nearly 2,600 healthy adults <a href="https://pubmed.ncbi.nlm.nih.gov/17299492/">found no association</a> between tea intake and ferritin levels, regardless of tea type, strength, or time of day.</li>
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<h2 class="wp-block-heading">Who Should Be Most Careful</h2>
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<p>“The significance of the interaction between iron and coffee or tea depends on the individual,” says Dr. Gold. Most healthy adults with normal iron levels probably don’t need to worry too much about coffee or tea lowering their iron. But this interaction matters more if you’re already at higher risk for iron deficiency, including <a href="https://www.hematology.org/education/patients/anemia/iron-deficiency">those who</a>:</p>
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<li>Have heavy menstrual bleeding</li>
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<li>Are pregnant or breastfeeding</li>
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<li>Eat a vegetarian or vegan diet</li>
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<li>Have celiac disease or inflammatory bowel disease</li>
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<li>Have had bariatric surgery</li>
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<li>Take <a href="https://medshadow.org/conditions-treatments/alzheimers-dementia/the-ppi-debate-are-heartburn-drugs-like-prilosec-and-nexium-linked-to-dementia/">proton pump inhibitors long term</a>, such as omeprazole (Prilosec) or pantoprazole (Protonix).</li>
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<p>If you fall into one of these categories, or you’re among the roughly <a href="https://ods.od.nih.gov/factsheets/Iron-HealthProfessional/">15% of Americans</a> who take an iron-containing supplement, making sure iron actually gets absorbed matters. So it’s worth talking to your doctor about checking your iron status. And you may also need to pay closer attention to when you drink your coffee or tea.</p>
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<h2 class="wp-block-heading">How to Take Iron if You Drink Coffee or Tea</h2>
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<p>If you are taking iron supplements for low iron, the simplest plan is to separate them from coffee or tea. The American Gastroenterological Association recommends <a href="https://www.cghjournal.org/article/S1542-3565(24)00410-5/fulltext">avoiding coffee and tea within one hour of taking oral iron</a>. Here are a few real-life ways to make this work:</p>
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<li><strong>Take iron first thing in the morning</strong>, then wait at least one hour before coffee or tea. If you sip coffee or tea all morning, take iron later in the day, ideally away from coffee, tea, and meals.</li>
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<li><strong>Try an iron supplement that you can stomach.</strong> “Ferrous sulfate is the most common oral iron supplement, but it tends to have the most gastrointestinal side effects,” Dr. Blyumin says, “so switching to something else, like ferrous bisglycinate, may be useful.”</li>
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<li><strong>Ask whether every-other-day dosing makes sense. </strong>Both Dr. Gold and Dr. Blyumin say “every other day” dosing of iron is usually <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC9892593/">as effective as daily dosing</a> and may be an option for some people to limit how many pills they take, save money, and potentially have fewer side effects. Ask your healthcare professional whether this is an option for you.</li>
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<li><strong>Take it with food if you have to</strong>. Though iron is best taken in the morning on an empty stomach, this <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC4336293/">can often cause nausea</a>. Just taking your iron is “more important than taking it at the optimal time,” says Dr. Gold. So if you can’t take iron on an empty stomach, go ahead and take it with a small amount of food. Another option is to have an early dinner, then take it at bedtime several hours after you last ate.</li>
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<li><strong>Check your levels</strong>. If you’re worried about your iron levels, or you have a known iron deficiency, ask your healthcare provider what labs to check and how often. This will help give you an idea of whether your coffee or tea is affecting your iron levels.</li>
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<li><strong>Consider pairing iron with vitamin C. </strong>Though the evidence is mixed on whether taking iron with vitamin C <a href="https://pubmed.ncbi.nlm.nih.gov/11124756/">improves iron levels long-term</a>, consider this pairing to boost short-term absorption.</li>
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<p>Like many supplements, iron shouldn’t be taken without medical guidance — especially given potential <a href="https://www.mdpi.com/2036-7481/12/2/33">gastrointestinal and gut microbiota side effects</a> — or used long term without follow-up. If you’re living with low iron, make sure you continue to monitor your levels with your doctor, and, if possible, leave some time between your morning coffee or tea and taking your supplement.</p>
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