Did you know there are more than a dozen different forms of magnesium, and each has a special super-power? Use this guide to make sure you’re using the correct form of magnesium for the problem you’re trying to solve.
Low levels of magnesium are linked to constipation, depression, heart-disease, diabetes, and even water retention. And while magnesium is an electrolyte, and plays a crucial role in proper hydration, the bulk of our magnesium comes from the food we eat, and not our water. (It’s filtered out of almost all drinking water at the source). For that reason, most people who are doing a “diet” (especially ketogenic dieters) are severely low in magnesium.
This is why most people eating a keto diet (and often people on ANY diet that restricts carbohydrates) struggle with low magnesium levels, constipation, headaches, and fatigue.
The good news is it’s easy to fix. Your body easily absorbs magnesium, and it’s inexpensive. The bad news is there are lots of choices, and it’s up to you to make sure the one you’re taking is best suited for the problem you’re trying to solve. So let’s dive in!
This is a great choice for general replenishment. Higher doses are also great for treating the constipation that can occur in a carb-restricted diet. This is the most studied form, and the most common form found on store shelves.
This one is often taken by people who are trying to solve a variety of digestion problems. It can provide short-term relief for heart-burn, indigestion, and constipation. There’s also some (limited) evidence that it could be useful for treating some types of migraines. However, the body tends to not absorb this as easily — so it’s not a great choice for general supplementation.
Magnesium Chloride and Sulfate
This is another one that’s easily absorbed, and perfect for general use and replenishing low magnesium levels. Some people use it in skin-cream to relax muscles, but there’s little evidence that it works topically.
You’ll commonly see this used as a food additive to enhance flavor, acidity and act as a preservative. This one is easily absorbed, and may be easier on the digestive system than other types. If you need regular, large doses of magnesium, this may be a good choice.
This occurs naturally in foods like fruit and wine. The acid has a sour taste, so it’s also often used as a food additive to enhance flavor or add acidity. Since it’s also easily absorbed, it’s a great option for general replenishment. There’s some (weak) evidence that it may help with fibromyalgia, and chronic fatigue syndrome. This one should be taken in the morning, since some people experience a small energizing effect from it.
Not only is this one easily absorbed, but it has a special super-power that none of the others do — It can cross the blood-brain barrier, and get directly into brain cells. For this reason, there’s some evidence that it can help manage certain brain disorders, such as depression and age-related memory loss. It’s also the best choice if your goal is to get a good night’s sleep! However, this one isn’t good for general supplementation, and it has no laxative properties.
Also known as “epsom salt”. Frequently dissolved in bathwater to soothe sore, achy muscles and relieve stress. It’s also sometimes included in skin care products, such as lotion or body oil.
Often labeled, sold, and used for its calming effects to treat anxiety, depression, and insomnia. However, there’s very little evidence that it can do any of these things, since it can’t cross the blood-brain barrier. Magnesium L-Threonate is the better choice. This one has no laxative properties, so it’s not going to help your “can’t poop situation”.
Athletes love this one. There’s some evidence that it’s good for heart health, and that it can improve energy production in your heart and blood vessel tissue.
Dosage and Warnings
The average recommended daily amount of magnesium is 320mg for women and 420mg for men. However, if you do activities that cause you to sweat, magnesium will leave the body rapidly, along with sodium, potassium, and calcium, so you may need extra replenishment.
Excessive doses may cause mild symptoms like diarrhea or upset stomach, but it usually takes quite a bit to cause problems.
Even higher doses can be unsafe, so be careful. If you take magnesium supplements and then have low blood pressure, confusion, slowed breathing, or an irregular heartbeat, get to an ER immediately.
People with kidney disease, heart disease, pregnant women and women who are breastfeeding also need to get advice on whether magnesium supplements are appropriate to take. And if you are currently taking any medications, be sure to inform your doctor before you incorporate magnesium supplements into your routine. As always, contact your doctor before making any changes to your diet or supplements.