Having low levels of magnesium is more common than you may realise, and can affect many areas of your health and wellbeing. If you’re plagued with poor sleep, tense muscles or low energy, magnesium could be a factor.
Magnesium’s role in the body is an important one, affecting everything from energy production, blood sugar balance, weight management and even mood to the regulation of muscle contractions and blood pressure. It’s perhaps no surprise that it’s the fourth-most abundant mineral in the body, and involved in more than 300 enzymatic reactions.
Read on for the signs and symptoms of low magnesium levels, as well how to address a deficiency.
Who is at risk of low magnesium levels?
Most people with magnesium deficiency are undiagnosed. This is because magnesium levels in the blood don’t accurately reflect the amount in your cells. While any of us may develop magnesium deficiency, it’s more common in certain groups, including children and adolescents, older adults and post-menopausal women. Those with certain health conditions may also be at greater risk, including conditions that impact the efficiency of the gut, such as coeliac disease and inflammatory bowel disease, as well as people with type 2 diabetes, eating disorders like anorexia or those with an alcohol dependency. If you’ve been prescribed medications, including diuretics or antibiotics, then you should be aware that these are known to deplete magnesium levels.
Discover our full range of health benefit guides including the best magnesium foods and the top 10 health benefits of magnesium.
Why might our diets be low in magnesium?
Many of us simply don’t get enough magnesium from our diets. Nutritional surveys support this, with reports of low magnesium levels among young adults, especially women. One reason for this is the high level of processed foods that many of us rely on for convenience and speed. Studies suggest that processing removes an estimated 80% of the magnesium from foods. Another factor is the declining magnesium content in many of our staple crops. Together these factors result in lower levels of magnesium in Western diets. Other dietary aspects that may affect our absorption of magnesium include a high intake of caffeine and zinc supplementation.
Low magnesium symptoms
The early signs and symptoms of low magnesium tend to be non-specific and hard to determine, although ongoing low levels may lead to deficiency and potentially result in chronic disease.
Common symptoms of low magnesium
1. Muscle twitches and cramps
Magnesium is a key electrolyte in the body. Electrolytes are electrically charged minerals that regulate nerve and muscle function, and maintain our hydration and pH levels. If the level of one or more electrolytes is out of balance, it can show up as frequent muscle cramps and twitches or even muscle tremors and weakness.
2. High blood pressure
Emerging evidence suggests magnesium may play a role in lowering high blood pressure, although more research is needed. That said, it does appear that a higher intake of magnesium may be effective for those with diagnosed high blood pressure (hypertension). The mechanisms behind this may be multifaceted. For example, magnesium helps manage levels of sodium, calcium and potassium, and together these minerals influence blood pressure. Magnesium may also help the release of prostacyclin, a hormone-like compound that relieves tension in blood vessel walls, thus reducing pressure.
3. Irregular heartbeat
An irregular heartbeat (arrhythmia) may be suggestive of a magnesium deficiency, although there are other explanations, so always consult your doctor if you have concerns. Irregular heartbeats often feel like a skipped beat or a palpitation and may cause dizziness or shortness of breath. Magnesium regulates calcium and potassium levels and these electrolytes help maintain the normal rhythm of your heart, so if magnesium is low you may sometimes feel as if your heartbeat is out of rhythm. Studies suggest magnesium may be especially helpful for a type of arrhythmia called atrial fibrillation.
4. Tiredness
Magnesium plays a key role in energy production and metabolism, so any shortfall may result in a lack of ability to fuel your day-to-day activities. Magnesium is also involved in nerve signalling and maintaining adequate potassium levels in muscles, so again a shortfall may add to fatigue.
5. Nausea, vomiting and loss of appetite
These may be indicators that levels of magnesium are low. If stomach issues persist, it may be worth mentioning this to your doctor, who may recommend a magnesium test.
6. Low mood
Low levels of magnesium may lead to apathy and a sense of emotional numbness. Supporting levels of magnesium through supplementation appears to help depression as well as other mood disorders like anxiety.
7. Breathing problems
Low magnesium levels may cause narrowing of the airways (bronchoconstriction), which is common in asthma. We need magnesium for muscle contraction and relaxation, including for the diaphragm and respiratory muscles.
8. Weaker bones
Bone density is not something you’ll tend to know about until you experience a break or a fracture. However, magnesium deficiency is a risk factor for low bone density (osteopenia) and the onward development of osteoporosis. Low magnesium levels will reduce blood levels of calcium, one of the main building blocks of bones, and may also impact vitamin D’s role in supporting bone strength.
If your deficiency becomes more pronounced then it may lead to chronic disease, including:
Heart disease
Osteoporosis
Type 2 diabetes
Migraine
Alzheimer’s disease
How to treat low magnesium
Although magnesium is found in a number of foods, including leafy green vegetables, nuts, seeds, wholegrains and dairy foods, you may not achieve the recommended daily amount of 270mg for women and 300mg for men unless you’re eating a varied diet. Therefore, it’s important to focus on a wide selection of foods to optimise your magnesium intake.
Supplements may be useful for some people, but always use as directed on the label. Taking high levels can result in side effects like diarrhoea, low blood pressure and mood disorders. If you’ve been diagnosed with a condition such as kidney disease, don’t supplement unless your doctor has specifically told you to do so. Those on prescribed medication including diuretics, heart medication and antibiotics should check with their prescribing clinician. If you’re taking antacids or laxatives, be aware that magnesium may affect the way these medications work.
Check out our tried-and-tested review of the best magnesium supplements.
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Kerry Torrens BSc. (Hons) PgCert MBANT is a BANT Registered Nutritionist® with a postgraduate diploma in Personalised Nutrition & Nutritional Therapy. She is a member of the British Association for Nutrition and Lifestyle Medicine (BANT) and a member of the Guild of Food Writers. Over the last 15 years she has been a contributing author to a number of nutritional and cookery publications including Good Food.
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