Caffeine is a natural stimulant. Some studies claim it interferes with the absorption of iron, but research is mixed.

In addition to helping you start your day in the morning, consuming caffeine has several beneficial effects, including a decreased risk of developing:

  • diabetes and pre-diabetes
  • stroke
  • cardiovascular disease

However, some studies claim that it may inhibit your body’s ability to absorb iron. Iron is essential for growth and development, as well as for other vital bodily functions.

Continue reading to discover more about the impact of coffee and caffeine on iron absorption.

Several studies have found that coffee and other caffeinated drinks can reduce iron absorption.

A 2021 study in 83 men found that heavy caffeine consumption was associated with reduced iron bioavailability, or the amount of iron that the body can utilize.

A 2023 study found that black tea and coffee were associated with a significantly increased risk of iron deficiency anemia. However, the researchers did not observe this effect in green tea.

A different 2023 study gave women with iron deficiency anemia iron supplements at different times of the day. They found that in women who took the supplement in the morning with coffee, iron absorption was reduced by 66%.

However, it is essential to note that the research findings are mixed.

A 2024 study in 113 individuals found that coffee consumption did not significantly affect serum iron levels.

Moreover, the inhibition of iron absorption may be caused by the polyphenols in coffee and tea, rather than caffeine itself.

Iron absorption is a complex process that is influenced by numerous dietary factors.

Certain types of foods enhance iron absorption, while others inhibit it. The type of iron you consume is also important.

Iron is present in food in two forms: heme and non-heme iron.

Non-heme iron, which is found mainly in plant-based foods, is relatively unstable and affected by many dietary factors. Non-heme iron accounts for approximately 90% of total iron intake, but only around 17% of it is absorbed.

In contrast, heme iron, which is found only in animal tissues (such as meat, poultry, and seafood), has a higher absorption rate of around 25%.

Consuming coffee and green tea may inhibit the absorption of non-heme iron.

Additionally, incorporating animal protein into meals can enhance the absorption of non-heme iron. This includes:

  • meat
  • fish
  • poultry

Vitamin C can also positively influence the amount of iron your body can absorb. Thus, including meat and vitamin C in meals with vegetables and other sources of non-heme iron can help your body absorb more iron.

Moreover, waiting one hour between consuming caffeine and meals or supplements containing iron may help improve absorption.

Drinking coffee or tea should not cause iron deficiency anemia in individuals who are not at a heightened risk.

Many people get enough iron from the food they eat. Regularly consuming an adequate amount of vitamin C and heme iron — found in meat, poultry, and seafood — can help counteract the iron inhibition caused by drinking coffee and tea.

However, for those at risk of iron deficiency, high consumption of coffee and tea may not be the best idea.

Groups at risk include:

  • women who menstruate, particularly those with heavy menstrual periods
  • women who are pregnant, breastfeeding, or have recently given birth
  • vegetarians and vegans
  • people who have undergone bariatric procedures, especially gastric bypass operations
  • people with certain medical conditions, like inflammatory bowel disease

Yet, it may not be necessary for these groups to completely cut out coffee and caffeine.

Instead, people at risk are advised to follow these tips:

  • drink coffee or tea between meals
  • increase vitamin C intake at mealtimes
  • eat iron-fortified foods
  • eat foods high in calcium and high fiber foods, like whole grains, separately from iron-rich foods.

This may help limit the effects that coffee and caffeinated drinks have on iron absorption.

Caffeinated drinks, such as coffee and tea, have been shown to inhibit iron absorption. However, this is more likely due to their polyphenol contents, not caffeine itself.

Caffeinated foods and drinks are not associated with iron deficiency in healthy individuals, as iron absorption is influenced by numerous other dietary factors.

However, those at risk of deficiency would benefit from avoiding coffee and tea at mealtimes and waiting an hour after drinking coffee or tea to eat a meal.