Magnesium is one of the most important minerals for good health, but over two-thirds of adults are thought to have a magnesium deficiency. Scarily, many of them are likely to have no idea, even as it wreaks havoc on their health. We explain why this happens, why it’s such a serious problem, and most importantly, what you can do to prevent it.
Why do I need magnesium?
Magnesium is one of 21 essential minerals that your body needs to survive and properly function. It’s also one of five electrolytes or electrically charged minerals that keep your body’s “electrical circuit” in good working order.
Magnesium is the fourth most abundant mineral in your body and is involved in over 300 biochemical reactions. These reactions control some super-critical functions like:
- Heartbeat, rhythm and function
- Blood pressure regulation
- Blood sugar control
- Protein synthesis (creation)
- DNA and RNA synthesis
- Energy production
- Nerve impulses
- Muscle contraction (including the heart muscle)
- Nerve-muscle communication
- Bone development and structure
- Immune function
- Antioxidant production
Magnesium also helps other minerals and electrolytes do their own jobs. For example, magnesium regulates certain hormones to send calcium into the bones, where it plays a major role in bone health and strength. Without magnesium, calcium is drawn out of the bones and stored in the soft tissues and organs instead, where it can cause serious damage.
What is magnesium deficiency?
Magnesium deficiency, or hypomagnesemia, means that you don’t have enough magnesium to meet your body’s requirements. This may be due to one or more of the following:
- Low magnesium intake from your diet
- Poor absorption of magnesium in the gut
- Excessive magnesium loss in the urine
It’s officially estimated that somewhere between 2.5-15% of the UK population are magnesium-deficient – that is, experiencing a frank deficiency.
However, according to an ongoing annual National Diet and Nutrition Survey by the UK Government and the Food Standards Agency, a substantial proportion of adults are not getting enough magnesium in their diets. That potentially means a lot of people are living with a subclinical deficiency.
Unfortunately, many people don’t realise they’re deficient in magnesium until these conditions are in full swing — if they realise it at all. Read on to find out why that is and what it means for your health…
What are the effects of magnesium deficiency?
Research shows that the lower your magnesium levels, the greater your risk of cardiovascular problems like coronary heart disease, hypertension (high blood pressure), and stroke. In fact, one research team says that even subclinical magnesium deficiency is so dangerous to heart health that it should be considered “a public health crisis”.
Magnesium deficiency can also significantly increase your risk of developing type 2 diabetes. It’s been found to increase depression risk by as much as 22%, and one research team was even able to create clinical anxiety in animals solely by reducing their magnesium intake.
There’s also evidence that magnesium deficiency is linked to migraine headaches, premenstrual syndrome (PMS), Alzheimer’s disease and ADHD.
What causes magnesium deficiency?
A common cause of magnesium deficiency is simply not eating enough magnesium-rich foods like leafy greens and whole grains (more on dietary sources later!). However, packing more of those foods into your diet doesn’t necessarily mean you’re getting enough magnesium.
Experts have found that the magnesium content of plants has seriously declined in recent decades, partly due to poor soil quality and contamination. Before you eat them, those plants are often heavily processed, depleting their magnesium content even more.
By the time they reach your plate, these supposedly magnesium-rich foods have nowhere near as much as they should have. That means you could be doing everything “right”, and still not be getting enough magnesium.
Magnesium deficiency can also be caused by deficiencies of other nutrients, like selenium or vitamin B6. On the other hand, too much calcium can reduce the amount of magnesium absorbed in the gut, and too much protein can make you lose more magnesium in the urine.
Certain health conditions can leave you deficient in magnesium, too. For example:
- Stress can deplete magnesium levels and interfere with digestion.
- Gastrointestinal disorders like Crohn’s, coeliac disease and ulcerative colitis can affect magnesium absorption.
- Kidney problems or type 2 diabetes can increase urination, which in turn increases magnesium loss.
- Alcoholism can cause many complications that affect magnesium levels in different ways, like kidney disease, vomiting, and digestive problems.
And if you’re taking medication for a health condition, you might also find your magnesium levels affected. Common culprits include some types of:
- Diuretics (to treat water retention or kidney dysfunction)
- Proton-pump inhibitors (to reduce stomach acid and treat reflux)
- Anti-diabetic medications (e.g. insulin)
- Antibiotic and antiviral medications
- Bronchodilators (to treat asthma and other respiratory problems)
- Bisphosphonates (to treat osteoporosis)
- Heart medications
- Chemotherapy drugs
How do I know if I have a magnesium deficiency?
Subclinical magnesium deficiency often has no symptoms. When symptoms do appear, they can easily be mistaken for other health conditions. For example, a migraine might happen as the result of a magnesium deficiency, but people will often view it as a separate condition in itself, and not a symptom of something else.
But let’s say you were to get a blood test, just to be sure. Most of the magnesium in your body resides in the tissues, not the blood. That means a blood test can give you a general snapshot, but it doesn’t really tell you much about what’s happening where it counts — in your cells.
And even if your bloodwork says that you’re above the clinical threshold for deficiency — everything looks A-OK here! — we know that doesn’t necessarily mean you don’t have a subclinical deficiency that could be messing with your health.
For those reasons, it can be really hard to know for sure if you have a magnesium deficiency. However, given the high number of people who don’t get enough magnesium in their diet, and the many potential conditions and medications that can cause magnesium deficiency, it’s safe to say that many of us out there could use a boost.
A good start is to track your eating habits for a week or two and see if you’re getting the required daily magnesium from your diet (remember to underestimate this, as there’s probably not as much magnesium in your food as there should be).
You can also look out for telltale signs of magnesium deficiency like:
- Muscle cramps, stiffness or spasms
- Eye twitches
- Headaches or migraines
- Numbness or tingling
- Irregular heartbeat or palpitations (a “fluttering” sensation in your chest)
- Anxiety, depression or low mood
How do you treat magnesium deficiency?
If you think you’re not getting enough magnesium, the first step is to add some more magnesium-rich foods to your diet. Don’t worry, there are plenty of tasty and nutritious options! Here are a few examples:
- Leafy green vegetables like spinach and kale
- Seeds and nuts, especially almonds, cashews and peanuts
- Lentils, beans and chickpeas
- Whole grains, quinoa and buckwheat
- Brown rice
- Fatty fish like salmon and mackerel
- Dark chocolate
Check out the following list of magnesium-rich foods for a deep dive into getting more magnesium in your diet.
But what if you’re finding it hard to get enough magnesium from diet alone, or you just want to give your levels and your health a boost? Well, then a magnesium supplement could be just what you need!
Magnesium supplements are a simple, convenient and effective way to keep your magnesium levels high and healthy. Even better, they usually include other healthful ingredients like amino acids, each with their own additional superpowers.
What’s the best type of magnesium supplement for deficiency?
Magnesium supplements are sold as a compound. For example, magnesium glycinate is magnesium and glycinate, magnesium citrate is magnesium and citric acid, and so on. There are lots of different types, each with its own uses and strengths.
For an overall boost to your magnesium levels, you’ll want to choose a type of magnesium with higher absorption and bioavailability. Magnesium malate, taurate and glycinate have the highest, while magnesium citrate and oxide are among the lowest.
You’ll also want magnesium in powder or capsule form, as topical magnesium products (e.g. Epsom salts and lotions) aren’t as well-absorbed through the skin.
To help you choose the right type for you, we’ve written a guide covering all the different types of magnesium and their benefits.
Are magnesium supplements safe?
If you have a health condition or take medications, like those we talked about earlier, then it’s likely your magnesium levels are on the low side. In that case, you may well benefit from a supplement, but it’s always best to check with your doctor first.
They may agree that you can benefit from magnesium supplements, but they’ll also need to carefully consider how they might interact with your health conditions and your medications. It’s best to leave that judgement up to the professionals, so book an appointment and have a chat with your doctor to be on the safe side.
For everyone else, magnesium supplements are generally considered safe. The most common side effect is digestive discomfort, e.g. diarrhoea, nausea or cramps, which is most likely with magnesium citrate or magnesium oxide. This is usually mild and resolves quickly, but in the meantime drink lots of water to avoid dehydration.
If the side effects don’t go away, get worse, or cause you too much discomfort, stop taking the supplements and consider giving your doctor a call.
How much magnesium should I take?
The NHS recommends that men aim to get 300mg of magnesium per day, while women should aim for 270mg. On the label of your magnesium supplements, it should tell you:
- How much magnesium (not magnesium citrate, oxide, etc.) a serving contains.
- How many units (e.g. capsules, scoops) make up a serving.
- Whether your daily dose is spread across multiple servings (e.g. morning and night).
Different brands might present this info differently, so read the label carefully to make sure you’re taking the right amount.
You’ll also see a number called the Nutrient Reference Value, or %NRV for short. This is the percentage of your daily magnesium needs the supplement meets.
Some supplements will provide 100% of your NRV or more, so you may wonder if this is safe, especially if you’re already eating magnesium-rich foods.
Don’t worry! For magnesium supplements, 350mg is the tolerable upper intake level (UL), or the level after which you’re more likely to experience side effects. Magnesium from food is not included in this total, so it won’t push you over the UL.
The threshold for magnesium toxicity is much higher than the UL, so you’d have to take a lot of magnesium to come close. Besides, your body is a pro at filtering out excess magnesium, especially from food.
Just follow the guidelines and the recommended dosage for your supplement and you shouldn’t have any problems.
Michelle Sinclair is a wellness enthusiast and writer specialising in natural health alternatives, supplements and nutrition.