Nutrition Diet: What vitamins should not be taken with coffee?

October 6, 2025 •

3 min read

According to research, drinking coffee with certain supplements can significantly reduce their effectiveness. A 2022 study found that iron absorption decreased by 54% when an iron supplement was taken with coffee by women with iron deficiency. This highlights why understanding what vitamins should not be taken with coffee is vital for your health regimen.

Quick Summary

Coffee contains compounds like caffeine and polyphenols that can interfere with the absorption and effectiveness of specific nutrients, particularly B vitamins, Vitamin D, and several key minerals. Understanding proper timing for supplements is crucial to maximize benefits.

Key Points

B-Vitamins: Coffee's diuretic effect may increase the excretion of water-soluble B vitamins like folate and B6, potentially reducing their levels.
Vitamin D: Research suggests caffeine intake might interfere with Vitamin D absorption by affecting its receptors.
Iron: Polyphenols in coffee bind to non-heme iron, significantly reducing its absorption; timing is important.
Calcium and Magnesium: Caffeine increases the urinary excretion and can reduce the absorption of these minerals.
Optimal Timing: Take vitamins and minerals at least one hour before or after coffee for proper absorption.
Less Affected Nutrients: Fat-soluble vitamins A and E are generally not significantly impacted by coffee and are best taken with a meal containing fat.

How Coffee Impacts Nutrient Absorption

Coffee contains caffeine and polyphenols that can interfere with the body's absorption of vitamins and minerals. Caffeine's diuretic effect increases the excretion of water-soluble nutrients, while polyphenols can bind to minerals, making them harder to absorb. Coffee's acidity may also affect nutrient digestion.

B-Vitamins and the Coffee Clash

Coffee can increase the excretion of water-soluble B-vitamins such as folate, B6, and B2 due to its diuretic properties. Some research suggests heavy coffee consumption may lead to lower B-vitamin levels. Polyphenols might also play a role in reducing B-vitamin absorption. B12 seems less affected, and coffee may even help its absorption by increasing stomach acid, but it's still advisable to separate coffee from B-complex supplements.

The Negative Interaction with Vitamin D

Studies suggest coffee might interfere with Vitamin D by potentially reducing the expression of its receptors, which could lower circulating Vitamin D levels. Since Vitamin D aids calcium absorption, this interference can indirectly impact bone health. Higher caffeine intake has been linked to a higher risk of Vitamin D deficiency in some research.

Key Minerals Also Affected by Your Brew

Coffee can significantly affect the absorption and excretion of important minerals.

Iron: Polyphenols in coffee bind to non-heme iron, drastically reducing absorption, potentially by up to 90%.
Calcium: Caffeine can increase calcium excretion in urine. While generally mild, heavy coffee consumption with low calcium intake could impact bone density.
Magnesium and Zinc: Polyphenols inhibit the absorption of magnesium and zinc, and caffeine increases magnesium excretion.

Your Optimized Supplement and Coffee Routine

The key to avoiding interference is separating coffee and supplement intake by at least one to two hours.

Take water-soluble supplements and minerals in the morning with water.
Wait at least an hour before having coffee.
Take fat-soluble vitamins (A, D, E, K) with a fat-containing meal to enhance absorption, preferably separate from coffee, especially if taking a multivitamin with minerals.
Consider taking supplements like magnesium in the evening.

Comparison of Nutrient Interactions with Coffee


Nutrient Type	Primary Interaction	Optimal Timing
B-Vitamins (Folate, B6)	Increased excretion due to diuretic effect	Wait 1-2 hours after taking supplements
Vitamin D	Potential interference with absorption via receptors	Wait 1-2 hours; take with a fat-containing meal
Iron	Absorption is greatly inhibited by polyphenols	Wait 1-2 hours; take with Vitamin C
Calcium & Magnesium	Increased urinary excretion and reduced absorption	Wait 1-2 hours, especially with high intake
Fat-Soluble (A, E)	Minimal direct interaction	Take with a meal containing fat, timing with coffee less critical for these specifically

Conclusion

For most healthy individuals who drink a moderate amount of coffee, the impact on nutrient absorption is typically mild. However, those with deficiencies, risk of deficiency, or heavy coffee drinkers should be mindful of timing. Separating supplements and coffee by at least an hour can prevent interference. Consult a healthcare provider for personalized advice, especially if you have concerns about nutrient levels or a diagnosed deficiency. For further information, the National Institutes of Health (NIH) Office of Dietary Supplements is a valuable resource {Link: NIH Office of Dietary Supplements https://www.goodhousekeeping.com/health/diet-nutrition/a65500983/vitamins-you-shouldnt-mix-with-coffee/}.

Frequently Asked Questions

It is not recommended. Most multivitamins contain minerals like iron, calcium, and zinc, and B-vitamins, all of which have their absorption negatively impacted by coffee's compounds.

You should wait at least one hour after drinking coffee before taking your supplements. For minerals like iron, a two-hour window is even better to maximize absorption.

Yes, even decaffeinated coffee contains polyphenols, such as tannins, which can bind to and inhibit the absorption of minerals like iron and zinc. However, the diuretic effect is removed, so water-soluble vitamin depletion is less of an issue.

Coffee contains polyphenols that form a complex with non-heme iron in the digestive system, making it much harder for the body to absorb. This can significantly reduce iron uptake from both food and supplements.

Most water-soluble B-vitamins, such as folate, B6, and riboflavin, are affected by coffee's diuretic effect. However, Vitamin B12 appears to be less impacted, and coffee can even help its absorption by increasing stomach acid.

To improve iron absorption, take your iron supplement separately from coffee, ideally in the morning on an empty stomach. You can also pair your iron-rich meals and supplements with a source of Vitamin C, which significantly enhances iron absorption.

Vitamin D is a fat-soluble vitamin and is best taken with a meal that contains healthy fats to maximize absorption. While coffee's interaction with Vitamin D is still being studied, it's prudent to take it at a different time from your coffee.