Depending on who you ask, a morning cup of coffee can range in importance from comforting ritual to non-negotiable life-giving sustenance. But regardless of where you land on the coffee enthusiast-to-fanatic spectrum, chances are you’ve spent a decent amount of time in the Starbucks drive-thru. After all, who doesn’t need an a.m. pick-me-up on occasion?
But here’s the rub: As wellness routines have expanded to include everything from magnesium and B12 to ashwagandha and berberine, the question of whether coffee consumption could interfere with supplement absorption has come up. That’s right, the TikTok gods have been sounding the alarm around how caffeine may impact the absorption of key nutrients. Some influencers even recommend spacing your coffee and supplements apart by at least one hour to make sure you’re reaping the most health benefits.
We asked top nutrition experts to set the record straight on how coffee affects supplement absorption. Spoiler: You can have your cake and eat it, too. You just need to know how to time things right.
- ABOUT OUR EXPERTS: Sunjya Schweig, M.D., founder of the California Center for Functional Medicine. Kiera Lane, N.M.D., MSAc, L.Ac., Dipl. Ac., is a naturopathic doctor and the director of Arizona Natural Medicine. Tansy Rodgers, F.N.T.P. is a functional nutritional therapy practitioner.
How Caffeine Interacts with Key Nutrients
Caffeine wakes you up by stimulating the central nervous system, but it also affects digestion and nutrient absorption in some subtle ways.
Read More: 6 Signs You’re Not Absorbing Nutrients Well—And What To Do About It
“When caffeine is consumed, it acts as a central nervous system stimulant by blocking adenosine receptors and triggering a rise in adrenaline and cortisol,” explains Sunjya Schweig, M.D., founder of the California Center for Functional Medicine. “This not only promotes alertness but also stimulates gastric acid, impacts digestion, and can increase the excretion of certain nutrients.”
Your body is resilient—but certain nutrients are more likely to be impacted when caffeine is in the mix. These are the ones most likely to be affected:
Iron: Coffee and other polyphenol-rich caffeinated drinks can reduce non‑heme iron absorption by up to 80 percent, depending on timing and concentration, according to Schweig. “Polyphenols in coffee bind iron in the gut and block its absorption—especially if consumed alongside supplements or iron-rich meals,” he says.
Calcium & Magnesium: These essential minerals play a vital role in bone health, nerve function, and muscle contraction. Caffeine’s mild diuretic effect can cause you to lose fluids more quickly, which may lead to increased excretion of calcium and magnesium through urine, explains naturopath Kiera Lane, N.M.D., MSAc, L.Ac., Dipl. Ac., director of Arizona Natural Medicine. If your intake is already on the lower side, that can add up.
B vitamins: B vitamins are key players in energy production and mood regulation. “Caffeine may interfere with the metabolism of B1 (thiamine) and speed up the loss of B12 through increased urination,” says Lane. “If your gut health isn’t in great shape to begin with, these effects may be amplified, making it harder for your body to hang onto these important nutrients.”
Good news: You don’t have to choose between your coffee and your supplements. A few smart timing tweaks can make a big difference.
Tips for Consuming Coffee if You Take Supplements
Want to get the most from your supplements without giving up caffeine? These strategies can help.
Wait an hour
Lane recommends waiting at least 60 minutes between consuming coffee and supplements—especially for iron, magnesium, and B12. Why? Caffeine can temporarily alter your stomach’s acidity and kickstart a stress response in the body, both of which can impact how well certain nutrients get absorbed, she explains. That one-hour buffer helps your digestion reset, so you absorb more of what you take.
Read More: How To Tell If Your Multivitamin Is Working
“This gap is especially critical for iron,” says Schweig. “Coffee consumed even one hour after an iron-rich meal can still suppress absorption, so the further you can space it, the better.”
Start with water
Hydrating first thing in the morning supports digestion, wakes up your metabolism, and preps your stomach to process nutrients effectively, explains Lane. A full glass of water before coffee or supplements sets the tone for the rest of your routine.
Have a quick bite
Fueling your body with a little something that contains protein and healthy fats—like a boiled egg, a spoonful of nut butter, or a slice of avocado toast—can help stabilize blood sugar before caffeine kicks in. This not only buffers the stimulating effects of coffee but also preps your digestive system to better absorb nutrients, according to Lane.
Pair brushing with dosing
Build a healthy habit by keeping your supplements next to your toothbrush. “This visual reminder makes it easier to remember your vitamins—even when mornings get hectic,” says functional nutritional therapy practitioner Tansy Rodgers, F.N.T.P. “Once you’ve had a small snack, brushing your teeth and taking your supplements can become a simple, reliable part of your daily routine.”
Does the Form of Your Supplement Matter?
When your mornings are busy, every little decision counts—including the form of your supplements. Tablets can be harder to break down and may not fully dissolve, according to Teitelbaum.
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“Capsules or liquids may have a slight edge in absorption, especially if they dissolve before coffee polyphenols reach the gut,” notes Schweig. “However, the bigger issue isn’t the form—it’s the timing. Coffee will bind and block minerals like iron and calcium no matter the supplement delivery system.”
Regardless of the format, spacing out your coffee and supplements gives your body the best chance to make use of what you’re taking.
What About Multivitamins?
Multivitamins may seem like a one-and-done solution, but they often contain a mix of nutrients that are particularly sensitive to caffeine’s effects—iron (when included), calcium, magnesium, and B-complex vitamins among them.
“Iron and zinc in multivitamins are particularly vulnerable to coffee’s polyphenols,” says Schweig. “And water-soluble vitamins like B1 and folate can be lost through increased urination. For best results, take your multivitamin at lunch or dinner when caffeine isn’t a factor.”
Signs You Might Not Be Absorbing Supplements Well
Still not sure if your coffee is messing with your supplements? There are a few subtle signs your body might not be absorbing nutrients as efficiently as it could, according to Rodgers.
- Low energy or brain fog, especially if you’re taking B12 or iron
- Muscle cramps or twitches, which may be linked to calcium or magnesium
- Brittle nails or thinning hair, often associated with biotin or iron
- Mood swings or trouble sleeping, which could signal B vitamin imbalances
“These symptoms are often nonspecific but could indicate nutrient deficiencies if your intake and absorption don’t match up,” says Schweig. “For example, persistent fatigue despite taking B12 might suggest poor timing with caffeine.”
Bottom Line
Coffee and supplements don’t have to compete. With just a few tweaks to your morning timing, you can support better nutrient absorption and still savor every sip of your favorite drink. Optimizing coffee and supplement absorption is less about perfection and more about consistency; small shifts can yield real benefits over time.
This article was reviewed by Brian Tanzer, nutritionist and Director of Scientific and Regulatory Affairs at The Vitamin Shoppe.