Can cloves cause iron deficiency? A look at nutrition and absorption

October 6, 2025 •

4 min read

While a tiny 2.1-gram teaspoon of ground cloves contains 0.25 mg of iron, this popular spice also contains compounds that can influence mineral absorption. A common question that arises is, can cloves cause iron deficiency through their impact on mineral uptake? The answer is nuanced and depends on the amount consumed and overall dietary patterns.

Quick Summary

Cloves contain tannins, which can inhibit the absorption of non-heme iron from food, but this is typically only a concern with excessive consumption. The impact is negligible in a balanced diet with normal spice use, and several strategies can mitigate any effect on mineral absorption.

Key Points

Tannins in Cloves: Cloves contain polyphenols called tannins, which can inhibit the absorption of non-heme (plant-based) iron in the digestive tract.
Normal Use is Safe: In typical culinary amounts, the effect of cloves on iron absorption is minimal and unlikely to cause a deficiency.
Heme vs. Non-Heme Iron: Heme iron from animal products is not significantly affected by cloves, while non-heme iron from plant sources is more sensitive to inhibitors.
Counteract with Vitamin C: Pairing iron-rich meals with foods high in Vitamin C can effectively counteract the inhibitory effects of tannins and other compounds.
Focus on Overall Diet: True iron deficiency is caused by a range of factors, including inadequate intake, blood loss, or malabsorption issues, not typically by normal spice consumption.
Risk Groups and Precautions: Vegetarians, vegans, and those with certain medical conditions should be most mindful of iron absorption, but simple dietary strategies can manage any potential issues.

The role of tannins in cloves

Cloves, the dried flower buds of the Syzygium aromaticum tree, are rich in powerful compounds called polyphenols, primarily tannins. Tannins are naturally occurring molecules found in many plant-based foods and beverages, such as tea, coffee, wine, and certain fruits. While these polyphenols offer antioxidant benefits, they are also known to be potent inhibitors of non-heme iron absorption.

Non-heme iron is the form of iron found in plant-based sources like spinach, lentils, and fortified cereals. When you consume cloves, especially in large quantities or with an iron-rich meal, the tannins can bind to the non-heme iron in your digestive tract. This binding process makes it difficult for your body to absorb the iron, thereby reducing its bioavailability. It is important to note that this effect is dose-dependent, meaning a small, normal amount of cloves used for seasoning is unlikely to cause a significant issue.

Heme vs. non-heme iron absorption

Understanding the two different types of dietary iron is crucial for grasping how foods like cloves can impact mineral uptake. The iron we consume comes in two forms:

Heme Iron: Found in animal products like red meat, poultry, and fish. It is highly bioavailable, and its absorption is largely unaffected by dietary inhibitors such as tannins.
Non-Heme Iron: Found in plant-based sources, as well as eggs and dairy products. It is absorbed less efficiently and is highly sensitive to both enhancers and inhibitors present in a meal.

Since cloves primarily inhibit the absorption of non-heme iron, individuals following vegetarian or vegan diets, who rely solely on plant-based sources of iron, may need to be more mindful of their intake of tannin-rich foods and beverages.

Other dietary factors influencing iron absorption

Cloves are just one of many dietary factors that can affect your body's ability to absorb iron. A holistic approach to your nutrition diet is the most effective way to ensure proper mineral status. Here are some key inhibitors and enhancers to consider:

Calcium: This essential mineral, found in dairy products and supplements, can inhibit the absorption of both heme and non-heme iron. For this reason, it is often recommended to take calcium and iron supplements at separate times of the day.
Phytates: Present in whole grains, nuts, seeds, and legumes, phytates can also bind to iron and hinder its absorption. Soaking, sprouting, or fermenting these foods can help to reduce their phytate content.
Oxalates: Found in vegetables like spinach, rhubarb, and beet greens, oxalates can inhibit iron absorption, though their effect is generally considered less significant than that of phytates or tannins.
Vitamin C: The most powerful enhancer of non-heme iron absorption. Vitamin C captures non-heme iron and converts it into a form that is more easily absorbed by the body. Pairing iron-rich plant foods with sources of vitamin C, like citrus fruits, bell peppers, or strawberries, can significantly increase absorption.

Table: Inhibitors and Enhancers of Iron Absorption


Dietary Factor	Effect on Iron Absorption	Food Examples
Tannins	Inhibit non-heme iron absorption	Cloves, coffee, tea, red wine
Phytates	Inhibit non-heme iron absorption	Whole grains, legumes, nuts
Calcium	Inhibit both heme and non-heme absorption	Dairy products, calcium supplements
Oxalates	Inhibit non-heme iron absorption	Spinach, rhubarb, cocoa
Vitamin C	Enhances non-heme iron absorption	Citrus fruits, strawberries, bell peppers
Meat, Fish, & Poultry	Enhances non-heme iron absorption	Beef, chicken, fish

Contextualizing the risk: When to be concerned

For the average person who uses cloves in modest amounts to flavor dishes, the risk of developing an iron deficiency is negligible. The issue becomes more relevant for individuals with underlying health conditions or specific dietary patterns that increase their risk of iron deficiency. These high-risk groups include:

Pregnant women: Require significantly higher iron intake.
Individuals with heavy menstrual bleeding: Blood loss is a leading cause of iron deficiency.
People with malabsorption disorders: Conditions like Celiac disease or Crohn's disease can impair the body's ability to absorb iron.
Vegetarians and vegans: Rely exclusively on non-heme iron, making them more vulnerable to the effects of dietary inhibitors.
Infants and young children: Have increased iron needs for growth and may have limited dietary intake.

Practical tips for a balanced nutrition diet

If you are concerned about your iron intake or are in a high-risk group, here are some practical nutritional strategies:

Eat heme iron sources: Incorporating lean red meat, poultry, or fish into your diet provides a highly bioavailable form of iron.
Pair plant-based iron with vitamin C: A squeeze of lemon juice over a spinach salad or adding bell peppers to a lentil stew can dramatically increase non-heme iron absorption.
Time your intake: Avoid drinking coffee, tea, or excessive consumption of cloves right before or after an iron-rich meal to minimize inhibitory effects.
Consider cooking methods: Soaking and sprouting legumes and grains can reduce phytate levels, improving iron availability. Cooking in cast-iron pans can also increase the iron content of your food.
Address underlying conditions: If you suspect an iron deficiency, it is crucial to consult a healthcare professional to determine the root cause, which may include screening for gastrointestinal issues or other sources of blood loss. Further information on iron deficiency symptoms and causes can be found on the Mayo Clinic website.

Conclusion

While cloves do contain tannins that can inhibit non-heme iron absorption, it is highly unlikely that normal culinary use will lead to iron deficiency. For the average person, the effect is negligible compared to other, more significant risk factors like diet composition, blood loss, or underlying medical conditions. Focusing on a balanced nutrition diet rich in iron-enhancing foods, especially Vitamin C, is the most effective strategy to ensure adequate iron status. As with any dietary concern, individuals in high-risk groups should seek professional medical advice to ensure their nutritional needs are being met effectively.

Frequently Asked Questions

Yes, cloves do contain a small amount of iron. A single teaspoon of ground cloves provides about 0.25 mg of iron, but this is a very minor contribution to overall dietary intake.

The tannins in cloves, a type of polyphenol, can bind to non-heme iron in the gut. This binding process reduces the body's ability to absorb the non-heme iron from the meal, thus decreasing its bioavailability.

Yes, it is safe to consume cloves regularly in normal culinary amounts. The health benefits of spices like cloves, such as their antioxidant properties, outweigh the minor and negligible effects on iron absorption in a balanced diet.

To maximize iron absorption, it is best to avoid consuming foods and beverages high in tannins (coffee, tea, wine), phytates (whole grains, legumes), and calcium (dairy) at the same time as an iron-rich meal.

Individuals who are at higher risk for iron deficiency, such as vegetarians, vegans, pregnant women, and those with heavy menstrual bleeding or malabsorption issues, should be most mindful of iron inhibitors.

While supplements can help correct a diagnosed iron deficiency, they should be used under medical supervision. For prevention, focusing on a varied and balanced diet that maximizes iron absorption is generally the best approach.

You can significantly enhance non-heme iron absorption by pairing iron-rich foods with sources of Vitamin C, such as citrus fruits, bell peppers, and strawberries. Eating a small amount of meat or fish with a plant-based meal also helps.