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Should You Take a Magnesium Supplement?


The suggestion to take any kind of supplement always raises the question, “Why do I need supplements to be healthy? Can’t I just get all my micronutrients from food?” After all, there was no Vitamin Shoppe in the Paleolithic. It seems silly that we should evolve to need a shelf full of pills just to function normally.

This is a very reasonable question, and it’s certainly better to ask for proof than to blithely stroll down the aisles of the drugstore tossing everything from Aluminum to Zinc into the shopping basket. On a diet of whole, nourishing foods (especially organic or grass-fed foods), you should be able to get everything you need. And there are plenty of natural sources of magnesium, including spinach, nuts, mineral water, and several kinds of fish. But a lot has changed since the caveman days, and there are a few major reasons why modern Paleo dieters might want to take one or two carefully-chosen supplements.

In the case of magnesium, the third argument is really the key. The magnesium content of foods depends on the soil they’re grown in, and that soil is becoming rapidly depleted by modern agriculture. The map here shows the magnesium content of soils across the United States, and in several areas, it’s very poor. In fact, the Nutrition Facts labels on fruits and vegetables may actually be misleading in some cases, because the soil has declined in quality since the USDA tested the foods. Purified water is also partly to blame: natural mineral waters (which is what we all drank before the advent of municipal water systems) contain high levels of magnesium, while the water that makes it out of your tap does not.

This is unfortunate, because magnesium is crucial for bone strength and development, and it’s required for over 300 enzymatic reactions, including many of the reactions that generate energy for your cells and control critical neurotransmitters. Deficiency can cause all kinds of symptoms including mental issues (difficulty concentrating and remembering things), muscle twitches and soreness, and a feeling of constant fatigue.

Since it’s reasonable to assume that Paleolithic humans got a lot more magnesium than we do (from their unprocessed water and foods grown in natural soils), magnesium supplements show some promise as an addition to the modern diet. Not everyone needs one, but if one or more of the problems below looks familiar to you, a magnesium supplement is a cheap and safe way to experiment with treatment.

Magnesium, Sleep, and Mental Health

Magnesium is well known for its ability to relieve insomnia. One study found that it helps decrease cortisol, the “stress hormone” that can keep you up at night. It also helps muscles relax, to give you that calm “sleepy” feeling and help you unwind after a long day. On top of helping you get a good night of sleep, it also shows potential as a therapy for depression and other mood disorders.

While most people find magnesium to be calming, others discover that it makes them feel more alert, and even uncomfortably wired. The reasons why this happens (and why it happens only in some people) aren’t clear, but one study showing the stimulant effects of magnesium in mice suggested the effect of magnesium on important neurotransmitters as a possible cause. If this is you, a magnesium supplement in the morning would be a better choice to reduce any micronutrient deficiencies without interrupting a restful night of sleep. And if the magnesium is causing extreme mood or insomnia problems, it’s best to stop taking it. After all, even a supplement that’s great in theory won’t help you if it makes you miserable in practice.

Magnesium and Constipation

Another major reason why people supplement with magnesium is to relieve constipation. Magnesium has a laxative effect because it draws water into the stools, making them softer and easier to pass. It’s also a muscle relaxant, so it eases any tension in the intestinal wall that might be causing constipation. It does work well, and it’s certainly much safer than commercial laxatives, but it’s important to note that magnesium usually doesn’t fix whatever underlying problem is causing the constipation; it’s more of a band-aid to treat the symptoms. For long-term relief, it’s better to identify and address whatever gut flora or food intolerance is causing the problem in the first place.

A caveat for this home remedy: it’s very easy to overdo the supplement and end up with the opposite problem from the one you started with. Start small and work up to a dose that loosens the stools just enough to make them easier to pass, without sending you dashing for the toilet every five minutes. If you do accidentally take too much, just wait it out and drink plenty of water to stay hydrated. It’s unpleasant, but it’s not dangerous, and the effects will pass.

Paleo Leap Meal Planner

Magnesium for Athletes

Everyone who’s ever pushed it a little too hard in the gym knows that sore, stiff, day-after “exercise hangover” that greets you the next morning. It’s not only from the burpees: magnesium deficiency can contribute to this, because of the way that calcium and magnesium work together in the muscles. It’s a complicated relationship, but essentially calcium contracts muscles, while magnesium relaxes them. A magnesium deficiency upsets this delicate balance, and muscle cramps and spasms are a common result.

Any kind of magnesium supplementation will help with this problem, but a bath with some magnesium-rich Epsom salts is particularly good because the hot water of the bath also helps relax the muscles – and who doesn’t love an excuse to take a long soak in the tub?

Magnesium and Insulin

As well as its other effects, magnesium also shows some promise for helping maintain insulin sensitivity and even blood lipid profile. To some extent, studies that show magnesium deficiency as associated with diabetes may actually be picking up the fact that most dietary magnesium is found in vegetables, and people who eat lots of vegetables are likely to be the health-conscious types who don’t eat a lot of sugary, carby junk food. But other studies with magnesium supplements do seem to support the theory that the magnesium itself has something to do with it, so recovering diabetics might do well to try out a magnesium supplement.

Types of Magnesium Supplements

It would be great if there was just one bottle on the supplement shelf labeled “magnesium.” But in fact there’s a whole row of different types of pills (magnesium citrate, magnesium glycinate, magnesium oxide), powders (Natural Calm), and topical applications (Epsom salts, magnesium oil) to choose from and the variety can be completely bewildering.

The only one of these to avoid is magnesium oxide, because it isn’t well-absorbed, and there’s no point spending money on supplements that your body can’t use. Pills containing other magnesium compounds are much more effective, and magnesium citrate is especially helpful for people looking for a way to treat constipation. For other problems, magnesium citrate can have an unwanted laxative side effect, so it might be more convenient to take it in a different form.

Natural Calm is many people’s favorite type of magnesium to take for insomnia. It comes flavored and unflavored; you just sprinkle it into a glass of water the same way you would with a package of Crystal Lite. Compared to magnesium in tablet form, Natural Calm is less likely to have a laxative effect, which is often an unpleasant side effect for people who just take magnesium to sleep better and don’t need any help with their bowels.

Epsom salts are another great option – sprinkle them in the bathtub and enjoy a long soak in the hot water while your body absorbs the magnesium through your skin. An equally effective (if less luxurious) option is the foot bath, just soaking your feet in a warm tub of water with some Epsom salts. For a topical application that you can use on the go, magnesium oil is a little more convenient than the Epsom salts, and easy to make at home. These preparations, like Natural Calm, don’t usually soften the stools at all.

Magnesium supplements

The Upshot

In a true hunter-gatherer society, we’d probably be able to get all the magnesium we need from our foods. Modern agriculture makes it a little harder, but for the supplement-averse, taking care to get plenty of leafy greens and seafood can help address the lack of magnesium in our food and water. Other people find that a supplemental form is more convenient and a simple way to address problems like constipation, insomnia, and muscle soreness after exercise. Whether it’s occasional supplementation to treat a specific problem or a regular daily dose, magnesium is definitely worth looking into, and it might be useful to give it a try.

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Hi I’m Ashley, I’m an ADAPT Certified Functional Health Coach

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