Iron Absorption: Why Eating More Iron Isn’t Always the Solution

You might have been told time and again to “just eat more iron” to fix low iron levels, whenever you feel a bit sluggish, or if you easily bruise. It’s common advice — but it’s not always the right one. Many people eat plenty of iron-rich foods and still struggle with low ferritin, fatigue, dizziness, or stubborn iron deficiency.

That’s because improving iron levels isn’t just about how much iron you eat. It’s about how well your body absorbs it. Factors like gut health, meal timing, other nutrients in your diet, and even the way your food is prepared can dramatically change how much iron your body actually takes in.

In this article, we’ll break down how iron absorption really works, what can block it, and simple ways to support better absorption naturally — so you know exactly what to do when eating more iron alone isn’t enough.

How is iron absorbed in the body?

To understand why iron levels don’t always rise—even when you’re eating more iron—we need to look at how the body absorbs it. Iron absorption is a surprisingly delicate process, and even small disruptions can affect how much iron actually reaches your bloodstream.

Haem vs non-haem iron

There are two forms of dietary iron:

1. Haem iron (animal-based)

• Found in: red meat, poultry, liver, seafood.
  
• Easier for the body to absorb — your gut can take in up to 30%.
  
• This is why foods like beef, lamb, kangaroo, and liver are some of the most reliable sources for improving iron levels.

2. Non-haem iron (plant-based)

• Found in: beans, lentils, leafy greens, nuts, seeds, fortified cereals.
  
• Much harder to absorb — sometimes as low as 2–5%.
  
• This form is affected most strongly by absorption blockers (like tea, coffee, or calcium).

Many people rely heavily on plant-based iron without realising how much harder the body has to work to absorb it.

Where does iron get absorbed?

Most iron absorption happens in the duodenum, the first part of the small intestine right after the stomach. This means:

• If the gut lining is inflamed
  
• If someone has coeliac disease, IBS, or low stomach acid
  
• Or if the microbiome is imbalanced

…iron absorption can drop dramatically, even with a great diet.

How vitamin C helps with iron absorption

Vitamin C is one of the most powerful ways to improve iron absorption naturally. It converts non-haem iron into a form the body can absorb more easily.

Examples of vitamin C–rich additions to meals:

• Capsicum
  
• Broccoli
  
• Citrus fruits
  
• Berries
  
• Kiwi

What are the common iron absorption blockers?

Even if you’re eating iron-rich foods every day, certain drinks, nutrients, and gut health issues can stop your body from absorbing that iron properly. These “iron blockers” are often the hidden reason why ferritin stays low, even with a good diet.

Here’s what can get in the way:

1. Tea and coffee

Tea and coffee contain compounds called polyphenols and tannins. These bind to iron in the gut and make it much harder for your body to absorb — especially non-haem iron from plant foods.

Tip: Try to keep away from tea and coffee one hour before or after iron-rich meals.

2. Calcium

Calcium competes with iron for absorption in the gut. This includes:

• Milk
  
• Cheese
  
• Yoghurt
  
• Calcium-fortified foods
  
• Calcium supplements

Tip: Avoid taking calcium supplements or having large dairy servings together with iron-rich meals.

3. Phytates & high-fibre foods

Foods like whole grains, legumes, nuts, and seeds contain phytates, which bind to minerals such as iron and reduce absorption.

These foods are healthy, but they’re best eaten away from your main iron-containing meals if you’re trying to increase ferritin.

4. Cocoa & red wine

These contain polyphenols similar to tea and coffee, which can reduce iron absorption when consumed at the same time as an iron-rich meal.

5. Gut inflammation or digestive conditions

Iron absorption happens in the duodenum — so anything that irritates or inflames the gut lining can block iron uptake.

Conditions that commonly interfere include:

• Coeliac disease
  
• Gluten sensitivity
  
• IBS
  
• Crohn’s disease
  
• Low stomach acid
  
• Chronic inflammation

When the gut lining isn’t healthy, iron can’t pass through efficiently — which is why diet alone sometimes isn’t enough.

6. Certain medications

Some medications can interfere with iron absorption, including:

• Antacids
  
• Proton pump inhibitors (PPIs)
  
• Some antibiotics

These reduce stomach acid or change the gut’s environment, making iron harder to absorb.

How to improve iron absorption naturally

You don’t necessarily need extreme diet changes or high-dose supplements to support better iron absorption. Small adjustments to how you eat can make a big difference in how much iron your body actually absorbs.

Here are simple, effective ways to support your iron levels naturally:

1. Pair iron with vitamin C

Vitamin C is one of the strongest enhancers of iron absorption, especially for plant-based (non-haem) iron.

Great vitamin C pairings include:

• Steak + capsicum
  
• Lentils + lemon juice
  
• Leafy greens + citrus dressing
  
• Iron-rich meals + berries, kiwi, or oranges

Even a small amount of vitamin C at mealtimes can increase absorption significantly.

2. Avoid tea and coffee around meals

As covered earlier, tea and coffee contain tannins that block iron absorption.

A simple rule: Wait at least one hour before or after eating an iron-rich meal.

This is one of the easiest ways to improve your iron levels without changing your diet.

3. Support a healthy gut

Because iron is absorbed in the small intestine, gut health plays a major role.

Helpful habits include:

• Eating probiotic-rich foods (yoghurt, kefir, sauerkraut)
  
• Including prebiotic fibre (bananas, oats, asparagus)
  
• Avoiding trigger foods that worsen gut inflammation
• Managing conditions like IBS or coeliac disease with your GP

Understanding inflammatory food triggers:

Gut inflammation can reduce how well your body absorbs nutrients, including iron. It’s helpful to identify and reduce foods that personally trigger symptoms for you — such as highly processed foods, excess sugar, artificial additives, or overly greasy meals.

Some people also assume that all red meat is inflammatory, but this isn’t the case. Fresh, minimally processed red meat can actually support iron levels and overall nutrition, especially because it contains haem iron, amino acids, and B vitamins. The types of red meat linked to inflammation are usually processed meats (like deli meats, bacon, or sausages) or red meat eaten in large quantities without enough vegetables or fibre.

The key is balance: pairing iron-rich foods with colourful vegetables, fibre, and healthy fats helps support a calm, healthy gut environment — which in turn improves iron absorption.

4. Choose iron-rich foods that are easier to absorb

Haem iron foods are naturally more absorbable. Examples include:

• Beef
  
• Lamb
  
• Liver
  
• Oysters
  
• Chicken thigh
  
• Chief Beef Bars (haem-iron rich wholefood option)

These are especially useful if you struggle to absorb iron from plant sources alone.

5. Space out calcium-rich foods

Calcium competes with iron for absorption. Try:

• Dairy at breakfast
  
• Iron-rich meals at lunch/dinner
  
• Calcium supplements taken far from meals (if prescribed)

6. Cook with cast iron

Cooking acidic foods (like tomato sauce) in cast iron cookware can naturally increase the iron content of your meals. It’s a gentle, easy way to add more absorbable iron without supplements, however, for individuals with a high demand for iron, it is still recommended to take additional iron supplements.

7. Stay well hydrated

Proper hydration supports digestion and nutrient absorption. Dehydration can slow everything down — including iron uptake.

The role of wholefood iron sources

When it comes to improving iron levels, what you eat matters just as much as how you eat it. Wholefood iron sources — especially those containing haem iron — are easier for the body to absorb and less affected by absorption blockers like phytates, tannins, or fibre.

Why wholefoods are more effective than fortified or processed options

Unlike fortified cereals or artificial iron additives, wholefood sources provide:

• Natural haem iron
  
• B vitamins (important for energy and red blood cell production)
  
• Zinc and other cofactors that help the body use iron effectively
  
• Amino acids that support gut repair and inflammation control

This nutrient synergy makes wholefoods particularly valuable for anyone with stubborn iron deficiency.

Wholefood convenience options: Chief Beef Bars & beef liver capsules

For people who don’t eat much red meat or prefer convenient, real-food options, products like Chief Beef Bars are an excellent alternative. They offer:

• Highly absorbable haem iron
  
• Protein to support gut repair
  
• A simple ingredient list with no preservatives or fillers

Similarly, beef liver capsules provide a wholefood source of iron, B vitamins, copper, and vitamin A — nutrients that work together to support healthy red blood cells and energy levels.

Read related article: Beef Liver Benefits: Why This Nutrient-Dense Food Should Be on Your Plate

These options are especially helpful for:

• Busy individuals
  
• People who don’t enjoy the taste of liver or red meat
  
• Those needing consistent haem-iron intake without relying on supplements

Where plant iron fits in

Plant-based (non-haem) iron foods — such as lentils, chickpeas, spinach, nuts, and seeds — are still valuable, especially when paired with vitamin C. However, because absorption is lower, many people use a combination of plant and haem iron sources to maintain healthy levels.

When should you consider iron supplementation?

Even with a balanced diet and careful meal planning, some people still struggle to lift their iron levels. That’s because iron deficiency isn’t always related to low intake — it can be caused by absorption issues, inflammation, gut conditions, or increased iron demands.

In these cases, supplementation may be necessary — but it’s important to do it safely and with proper guidance.

Consider speaking with your GP about iron supplementation if you experience:

• Low ferritin that doesn’t improve despite eating iron-rich foods
  
• Persistent fatigue, shortness of breath, or low energy
  
• Heavy menstrual bleeding
  
• Pregnancy or breastfeeding (higher iron needs)
  
• Digestive conditions like coeliac disease, IBS, or gastritis
  
• A history of low stomach acid or long-term PPI use

These factors make iron harder to absorb, meaning food sources may not be sufficient.

Why supplements aren’t always a quick fix

Iron supplements can be helpful, but they’re not a magic solution — and they don’t work for everyone. Some of the most common reasons include:

• The type of iron used (some forms absorb poorly)
  
• Gut irritation making absorption difficult
  
• Taking supplements with tea, coffee, dairy, or calcium-rich foods
  
• Underlying inflammation blocking iron uptake

If you’ve tried oral iron and your levels still don’t rise, it’s worth revisiting the basics of absorption — and seeing your GP for further investigation.

Read related article: Iron Supplements Not Working? Here's What Might Be Going Wrong

When IV iron is considered

Intravenous (IV) iron may be recommended when:

• Oral iron isn’t tolerated
  
• Levels are severely low
  
• Absorption is impaired
  
• Fast improvement is medically necessary

This is always done under medical supervision.

Supplements vs wholefood iron

For many people, combining:

• Wholefood haem iron sources
  
• Vitamin C
  
• Timing adjustments
  
• Gut health improvements

…can significantly improve iron levels before supplements are needed.

Supplements have their place — but they work best when the underlying absorption issues are addressed.

Conclusion: It’s not what you eat — it’s what you absorb

Low iron isn’t always caused by not eating enough iron. For many people, the real issue lies in absorption — how well the body can take in and use the iron from food. Gut health, meal timing, vitamin C, and certain foods or drinks can all influence how much iron actually makes it into your bloodstream.

By understanding these factors and making small adjustments, you can support better absorption naturally and get more benefit from the iron-rich foods you’re already eating. And if your iron levels still don’t improve, it may be time to speak with your GP about supplementation or further investigation.

Improving iron levels is rarely about doing more — it’s about doing what works smarter.

Shop Chief Nutrition: Real Ingredients, Real Iron, Real Nutrition