Can You Take Iron and Magnesium Together?

It is important to know what iron and magnesium are used for, and what the signs and symptoms are that you may be deficient in these vitamins. 

This article will help you understand why iron and magnesium supplements are taken and when you should take them. It will also help you learn what foods can be eaten that help you maximise your iron and magnesium intake as well as some useful tips.

What is iron?

Iron is an important mineral for physical growth and development and is essential for the function of haemoglobin. Haemoglobin is a protein in red blood cells that allows oxygen to bind to the red blood cells and be transported around the body in the bloodstream. Each healthy adult has between 3-4g of iron stored within the body.1

There are two types of dietary iron:2

  • Haeme iron: It is most easily absorbed and obtained from animal sources
  • Non-haeme iron: It is less easily absorbed and obtained from plant sources

Low iron levels or iron deficiency is a common condition affecting many people. Low haemoglobin and iron levels cause anaemia. Children, women, and pregnant women are most likely to suffer from iron deficiency. This will be discussed more in the symptoms and causes of iron deficiency. Iron deficiency is treated with iron supplement tablets and by consuming iron-rich foods. These include:3

  • Meats and some small fish such as anchovies
  • Leafy greens
  • Iron-fortified foods
  • Beans, lentils, and peas

Symptoms and causes

Iron deficiency and low haemoglobin levels cause anaemia. This is a condition where you lack adequate healthy red blood cells to transport oxygen around the body.

Some of the symptoms of iron deficiency anaemia include:3

  • Pale skin
  • Sensitivity to the cold
  • Shortness of breath
  • A lack of energy or fatigue
  • Hair loss, nails becoming brittle
  • Feeling lightheaded

An increased requirement for iron and a decreased ability to absorb iron are the most common causes of iron deficiency and anaemia.

Increased requirement

As your body changes throughout your life, your iron demand also changes. Many of these changes can cause your iron demand to increase. These include: 

  • Adolescence (as your body is growing rapidly)
  • Menstruation
  • Pregnancy
  • Lactation
  • Surgery
  • Other - this includes medications such as ibuprofen, supplements, injuries, stomach ulcers, and surgery

Decreased intake/ability to absorb iron

Many factors can decrease or inhibit iron absorption:

  • Consuming a plant-based diet low in iron
  • Certain medications including some antibiotics
  • Autoimmune disorders such as Coeliac and Crohn's disease

Certain foods and drinks can also reduce iron absorption. Tea and coffee contain polyphenols that can inhibit iron absorption. Compounds called phytates that are frequently consumed in plant-based diets can also decrease iron absorption.

What is magnesium?

The human body contains around 25g of magnesium. Magnesium has many functions within our cells. These include the synthesis of DNA and proteins for muscle and nerve function, as well as maintaining intracellular gradients of important ions in the body. 

Magnesium is also required for many of our enzymes to function correctly and allows us to convert food to energy.4 60% of magnesium is located within our bones and 40% is present in muscles and soft tissue.5

Food sources of magnesium include:

  • Nuts: almonds, cashews and peanuts (including peanut butter)
  • Black beans and kidney beans
  • Dark leafy greens such as spinach and chard
  • Salmon
  • Beef and poultry (e.g., chicken, pork)
  • Seeds
  • Dark chocolate with content of 70% or above

Symptoms and causes

For many people, the symptoms of magnesium deficiency do not become apparent until their magnesium levels are severely low. This means it can be difficult to recognise and treat at early stages. Luckily, magnesium deficiencies are relatively uncommon. 

That said, symptoms may include:4

  • A loss of appetite
  • A lack of energy or general fatigue
  • Muscle cramps
  • Muscle weakness
  • Nausea and/or vomiting

As these symptoms are relatively generic on their own, experiencing multiple symptoms at the same time may make it easier to distinguish other conditions from a magnesium deficiency. 

Causes of low magnesium levels and magnesium deficiency include:

  • An increased excretion of magnesium: increased levels of calcium (hypercalcaemia) can increase how rapidly magnesium is removed from the body through urine
  • A reduced intake of magnesium in the diet
  • Medications including drugs to treat acid reflux (I.e. omeprazole)

Other medications that decrease magnesium levels include diuretics, antibiotics, immunosuppressants and other drugs as listed here.

Can you take iron and magnesium together?

Yes, you can take iron and magnesium glycinate supplements together. There are no known interactions between iron and magnesium supplements and they are safe to take together. 

However, there is a study that found there may be a link between magnesium oxide supplements and a decreased absorption of iron that can contribute to anaemia. This is because magnesium oxide can alter the pH of the body that prevents iron absorption.11,12

For this reason, it is safer to take magnesium glycinate tablets with iron supplements than magnesium oxide and other magnesium supplements.

Recommended daily intake

When taking iron and magnesium supplements, it is helpful to know that:

  • To increase the absorption of iron from the tablets, you can drink a glass of orange juice
  • To minimise the side effects of iron and magnesium tablets, try to take them before or during meals. This can also help your body absorb the supplements better


The form of iron used in iron supplements is often ferrous sulphate. The recommended daily intake of iron varies depending on your gender assigned at birth and your age.7

  • Adult women (19-50) - 18 mg
  • Males (19-50) - 8 mg
  • Pregnancy - 27 mg
  • Menopause - 8 mg (if menstruation  has stopped)

If you want to increase your iron levels, try to consume more foods rich in iron. You can also consume a source of vitamin C (e.g. orange juice) with your meal to help your body absorb iron. 

Not only can low iron levels be damaging, but high iron levels can also cause problems. Iron overload can damage the heart and liver so ensure you are not taking more than your recommended daily intake described above.2

Folic acid, or vitamin B9 is also used to treat iron deficiency anaemia because folic acid, or folate, is required to produce healthy red blood cells.9 Specifically, it is used to treat folate deficiency anaemia and is only prescribed when you are diagnosed with this type of anaemia.


Magnesium supplements for a deficiency are called magnesium glycinate. The recommended daily intake for magnesium for adults is approximately 4.5mg/kg per day, which works out to around 350 mg per day for the average adult.5 

Take care to not exceed 350 mg per day from supplements as higher doses can cause side effects including:

  • Cramping
  • Diarrhoea 
  • Nausea

However, higher quantities of magnesium absorbed from food is safer than supplements as the excess magnesium can be safely removed in the urine.

There are other types of magnesium supplements available. These include: 

Magnesium oxide 

This is another common magnesium supplement. This form has more magnesium within the tablets than magnesium glycinate; however, absorption of magnesium from magnesium oxide tablets is lower. This supplement is used more commonly to treat migraines and constipation.8

Magnesium citrate

Instead of treating magnesium deficiency, it is used to treat constipation by acting as a laxative.10 Do not take other laxative medications when you are taking magnesium citrate. Take care of the fact that magnesium citrate may reduce the efficacy of your iron tablets.11,12

When to seek medical advice

It can be difficult to know if your symptoms indicate a deficiency. If you are unsure if you have symptoms of anaemia, it is advisable to speak to a health professional. Untreated anaemia can increase your risk of infection as low iron levels weaken your immune system. It can also increase your risk of heart problems and complications associated with pregnancy.

In the same way, if you believe you may have a magnesium deficiency, speaking to a health professional is advisable.


Vitamins and minerals are very important for living a long and healthy life. Both iron and magnesium have multiple functions in the body, so ensuring you are consuming enough through diet or supplements is crucial to prevent deficiency. Please consult with a healthcare professional before beginning to take a new vitamin.

The key takeaways are:

  • Yes, iron and magnesium supplements can be taken together safely but magnesium oxide with iron supplements should be avoided
  • Iron deficiency is common and affects many people with noticeable symptoms and is treated with diet changes and supplements
  • Magnesium deficiency is less common and has fewer symptoms
  • There are multiple types of magnesium supplements which can be used for different purposes. For preventing and treating magnesium deficiency, magnesium glycinate is most suitable
  • Do not exceed 350mg per day of magnesium or 17mg of iron from supplements unless you are advised to do so by a healthcare professional
  • Ensuring you are taking the correct dosage of vitamins is important to prevent side effects


  1. National Institutes of Health. Iron [Internet]; 2022. Available from: 
  2. ms T, St Lucia K, Huecker MR. Biochemistry, Iron Absorption. StatPearls; 2022 
  3. NHS. Iron Deficiency Anaemia [Internet]; 2021. Available from: 
  4. Health Guide. Magnesium Deficiency: 10 common signs and symptoms [internet]; 2019. Available from: 
  5. Swaminathan R. National Library of Medicine. Magnesium Metabolism and its Disorders. Clin Biochem Rev 2003; 24(2):47-66. 
  6. Harvard T.H Chan. The Nutrition Source. Magnesium [Internet]; 2019. Available from:,lactation%2C%20310%2D320%20mg
  7. Harvard T.H Chain. Th Nutrition Source. Iron [Internet]; 2019. Available from: 
  8. DifferenceBetween.Com. What is The Difference Between Magnesium Oxide and Magnesium Glycinate [Internet]; 2022. Available from:,but%20its%20absorption%20is%20high
  9. NHS. About Folic Acid [Internet]; 2022. Available from: 
  10. Magnesium Citrate [Internet]; 2021. Available from: 
  11. Sugimoto, H., Yamada, U. Iron Deficiency Anemia Inducd my Magnesium Overuse: A Case Report. BioPhyscosocial Medicine 2019; 13(18).
  12. Disch G, Classen HG, Haubold W, Spätling L. Interactions between magnesium and iron. In vitro studies. Arzneimittelforschung 1994; 44(5): 647-650. 
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Laura Preece

BSc Pharmaceutical Sciences and MRes Pharmacy and Pharmaceutical Sciences
I am a researcher and medical writer with a passion for pharmaceutics, disease and biological sciences. I am currently researching cellular and molecular biology, investigating the use of vitamin C as an adjunctive therapy for diabetes mellitus.

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