Most people think of magnesium as the mineral that helps prevent muscle cramps. While it certainly plays an important role in healthy muscles and nerves, scientists now know that magnesium is involved in hundreds of processes throughout the body. It supports energy production, heart function, bone health, metabolism, and importantly, the normal functioning of the immune system. 

For people living with allergic diseases such as asthma, eczema, allergic rhinitis, or food allergy, maintaining good overall nutrition is an important part of supporting health. Although magnesium is not a treatment for allergic disease, ensuring adequate magnesium intake may help support the body’s normal immune and inflammatory processes. 

A mineral working behind the scenes 

Magnesium is one of the most important minerals in the human body. Around 99% of the body’s magnesium is stored inside cells, bones, and other tissues, with only about 1% circulating in the bloodstream. 

This means magnesium works largely behind the scenes, helping cells produce energy, supporting communication between nerves and muscles, activating hundreds of enzymes, and assisting in the production of DNA and proteins. Every organ in the body depends on magnesium to function normally. 

Because magnesium is involved in so many different processes, low magnesium levels can affect several body systems rather than causing one specific problem. 

Magnesium and your immune system 

Your immune system depends on a delicate balance. It needs to protect you against infections while avoiding unnecessary or excessive inflammation. 

Magnesium contributes to several important immune functions. It helps support the activity of immune cells, including T cells, which play an important role in recognising and responding to harmful organisms. Magnesium also plays a role in the normal functioning of immune cells involved in antibody responses and participates in several biochemical processes involved in innate immunity, including aspects of complement activation. 

Scientists also know that magnesium helps regulate inflammatory pathways within the body. When magnesium levels are low, some inflammatory processes may become more active. 

However, it is important to understand what this does and does not mean. While adequate magnesium supports the normal function of the immune system, there is currently no evidence that magnesium supplements prevent or treat allergic diseases such as eczema, asthma, allergic rhinitis, or food allergy. 

What does this mean for people living with allergies? 

Living with an allergic disease often means managing ongoing inflammation. Good nutrition supports overall health, but no single vitamin or mineral can replace evidence based allergy treatment. 

Current research suggests that maintaining healthy magnesium levels forms part of good general health and may support the body’s normal immune regulation. It should be viewed as one piece of a healthy lifestyle that includes a balanced diet, regular physical activity, good sleep, stress management, and following your prescribed allergy treatment plan. 

For people with asthma, magnesium has attracted particular interest. In hospital settings, intravenous magnesium may sometimes be used by healthcare professionals during severe asthma attacks that do not respond well to standard treatment. This is a specialised emergency treatment and should never be confused with taking magnesium supplements at home. 

Who may be at greater risk of magnesium deficiency? 

Magnesium deficiency is thought to be more common than many people realise, particularly because early symptoms can be vague and non specific. 

Some people are at greater risk than others, including those who: 

• Eat a diet high in processed foods and low in whole foods. 
• Have digestive conditions that reduce nutrient absorption, such as coeliac disease, inflammatory bowel disease, or chronic pancreatitis. 
• Have type 2 diabetes or metabolic syndrome. 
• Take certain medications, including some long term proton pump inhibitors used for acid reflux, certain diuretics, or some chemotherapy medicines. 
• Consume excessive amounts of alcohol. 
• Are older adults, where dietary intake, absorption, and medication use may all contribute to lower magnesium levels. 

People with multiple food allergies or restrictive diets may also benefit from reviewing their nutritional intake with a registered dietitian to ensure they are meeting their magnesium requirements safely. 

Could you be low in magnesium? 

The signs of magnesium deficiency are often non specific and can develop gradually. 

Possible symptoms include: 

• Muscle cramps or twitching. 
• Fatigue. 
• Weakness. 
• Headaches. 
• Tremors. 
• Tingling sensations. 
• Heart rhythm disturbances in more severe cases. 

These symptoms are not unique to magnesium deficiency and can have many different causes. If you are concerned, speak to your healthcare professional rather than self diagnosing. 

Can magnesium deficiency be tested? 

Yes. In South Africa, doctors usually start with a serum magnesium blood test. However, because most of the body’s magnesium is stored inside cells and bones rather than in the bloodstream, a normal blood result does not always rule out low magnesium stores. Your healthcare professional will also consider your symptoms, diet, medications, and overall health when assessing whether you may have a magnesium deficiency. 

Routine magnesium testing is not recommended for everyone with allergic disease. Your healthcare professional may recommend testing if you have symptoms suggestive of deficiency or if you have certain medical conditions or take medications that increase your risk of low magnesium levels. 

Getting enough magnesium 

For most people, the best source of magnesium is a balanced, varied diet. 

Foods naturally rich in magnesium include: 

• Green leafy vegetables such as spinach. 
• Beans and lentils. 
• Whole grains. 
• Pumpkin and sunflower seeds. 
• Almonds and cashews. 
• Avocados. 
• Dark chocolate with a high cocoa content. 

If you have food allergies, there are still many safe ways to include magnesium rich foods in your diet. For example, if you are allergic to tree nuts, you may still obtain magnesium from legumes, leafy vegetables, seeds (if tolerated), and whole grains. 

Magnesium supplements are not necessary for everyone and should not replace a healthy diet. They may also interact with certain medications or be unsuitable for people with kidney disease. Always discuss supplements with your healthcare professional before starting them. 

The bottom line 

Magnesium is far more than a mineral that helps prevent muscle cramps. It is involved in energy production, muscle and nerve function, heart health, metabolism, and the normal functioning of the immune system. 

For people living with allergic disease, maintaining adequate magnesium intake supports overall health, but it is not a treatment for allergies or a substitute for prescribed medication. 

A nutritious diet, appropriate medical care, and evidence based allergy management remain the foundations of living well with allergic disease. 

Further reading: This article was inspired by a presentation by Dr Rodney Hudson on the evolving role of magnesium in health. Readers who would like to learn more can access the original summary article and webinar replay here:
https://newmedia.b2bcentral.co.za/c00be5d5-b62f-47fe-a2bc-01e73bf583c3/index.html 

AFSA Tip: Before taking any nutritional supplement, speak to your healthcare professional, particularly if you have a chronic medical condition, kidney disease, take regular medication, or have multiple food allergies.