Your morning coffee can offer some impressive health benefits, from reducing the risk of diseases like type 2 diabetes and liver cancer to boosting concentration and energy.
But if you’re washing down your daily supplements with it, you might be missing out on some of their benefits.
Here’s what you need to know about how coffee impacts vitamin and mineral absorption.
Research shows that coffee can reduce the absorption of certain nutrients.
Coffee contains caffeine and tannins, which are types of polyphenols that combine with minerals such as calcium, magnesium, zinc, phosphorus, and iron, and prevent their absorption.
There’s also some evidence that heavy coffee consumption may affect B vitamin levels. For example, higher coffee intake has been linked to lower folate levels in certain studies.
However, researchers note that more studies are needed to determine exactly how coffee impacts B vitamin absorption or metabolism, and whether these effects are significant in people with balanced diets.
Drinking coffee may impact the absorption of certain nutrients and increase your body’s excretion of others.
- Iron: Coffee contains polyphenols that inhibit non-heme iron absorption. Studies show reductions of 40–90%, depending on the polyphenol content and coffee type.
- Calcium: Studies show that caffeine consumption can slightly increase urinary excretion of calcium, which may result in a decrease in bone mineral density, particularly in those who follow low-calcium diets and in people with inflammatory bowel disease (IBD).
- Zinc: “Coffee also inhibits zinc absorption, but to a lesser degree than iron,” Steph Greunke, MS, RD, CPT, PMH-C, told Health. The tannins and caffeine in coffee bind with zinc, making it less available for the body to absorb.
- B vitamins: Some evidence suggests that caffeine intake reduces blood levels of folate, though the exact mechanism isn’t fully understood. While more research is needed, some studies have found an association between high caffeine or coffee consumption and lower folate status.
- Vitamin D: Higher caffeine intakes may be associated with lower vitamin D levels. A 2021 study found that people with the highest dietary caffeine intake had 48% higher odds of having vitamin D deficiency compared to people with the lowest intake. However, more research is needed.
- Magnesium: Research shows that caffeine may increase magnesium excretion. Though moderate coffee consumption likely won’t have a significant impact on magnesium status, chronic, high coffee consumption may lead to low magnesium levels.
Keep in mind that while drinking coffee may decrease the absorption of or increase the excretion of certain nutrients, these effects are generally mild and unlikely to cause low nutrient levels if you’re eating a balanced diet.
However, excessive coffee consumption may lead to low levels of certain nutrients, like iron and calcium, especially in people with poor dietary intake and those with preexisting health conditions.
It’s best to time your coffee intake accordingly to maximize nutrient absorption, especially if you’re taking supplements.
Drinking coffee with an iron-rich meal can reduce absorption by 39 to 90%. However, studies found no decrease in iron absorption when coffee was consumed one or two hours before a meal.
You should also wait at least one hour before or after coffee to take other minerals, like zinc, magnesium, and calcium, as well as multivitamins that contain minerals.
In addition to timing, it’s important to limit your overall caffeine intake and follow a balanced diet to maintain optimal nutrient levels. Consuming too much caffeine can also lead to side effects like anxiety, rapid heartbeat, agitation, and trouble sleeping.
It’s recommended that adults keep their intake to less than 400 milligrams per day, or around 4 cups of caffeinated coffee.
Caffeine has little to no effect on the absorption of many common supplements. Most fat-soluble vitamins, including vitamins A and E, as well as water-soluble vitamins like vitamin C and vitamin B12, are not significantly impacted.
Additionally, supplements such as omega-3 fatty acids and probiotics are generally unaffected by caffeine and can be taken alongside your morning coffee without concern.
Here is a morning routine to prioritize nutrient absorption while enjoying your morning coffee:
- Start with water: Drinking water before your coffee helps keep you hydrated, prevent dehydration, and support healthy digestion.
- Time your coffee wisely: Try to avoid drinking coffee immediately before or after taking supplements that contain iron, calcium, zinc, or magnesium, as it may interfere with the absorption of these nutrients.
- Take certain supplements with food: Fat-soluble vitamins, like vitamins A, D, and E, are best taken with food to maximize absorption.
- Don’t stress: While drinking coffee alongside certain supplements can affect their absorption, doing so now and then isn’t something to worry about. What matters most is sticking to a consistent supplement routine to help support and maintain healthy nutrient levels over time.
Coffee comes with impressive health benefits, but pairing your morning brew with certain supplements may interfere with how well your body absorbs key nutrients.
If you’re taking supplemental minerals, like iron and zinc, it’s best to take them 1–2 hours before or after coffee to optimize their absorption.
