Everything You Need to Know About Magnesium


Do you need more magnesium? Likely, the answer is yes. After almost 10 years working as a private practice dietitian, magnesium is my number one recommended supplement. Only recently has magnesium gotten the spotlight it deserves. 

Did you know that magnesium is the fourth most abundant mineral in the human body? It acts as a cofactor or activator in more than 600 enzymatic reactions that can affect you from your nervous system all the way to your bones. Magnesium is required for DNA synthesis, reproduction, energy production, blood pressure regulation, insulin metabolism, adrenal function, nervous system transmission, bone health, and more! 

The recommended dietary allowance (RDAs) for magnesium for adult men and women is 420 mg and 320 mg per day respectively. However, more than 50% of Americans are not getting enough for many reasons. Firstly, most Americans do not consume enough magnesium rich foods such as properly prepared beans/legumes, nuts/seeds, whole grains, and leafy greens. Furthermore, soil magnesium content is declining due to modern day agricultural practices, which is leading to lower magnesium content in our produce.  Secondly, the modern day high-stress lifestyle along with high consumption of coffee and alcohol leads to rapid cellular use of magnesium. Some medications even waste magnesium, especially diuretics and birth control pills. Finally, some health conditions such as diabetes and digestive disorders can lead to magnesium depletion. 

As you can see, many factors can contribute to your unique magnesium status. Although severe magnesium deficiency is not common, mild deficiencies are and can contribute to the development of chronic health conditions. Individuals at highest risk are the elderly and those with multiple confounding factors. Common signs and symptoms of mild magnesium deficiency include constipation, fatigue, sleep disturbances, anxiety, cramps in legs and feet, headaches or migraines, PMS, poor bone health, and more.

How can you test your magnesium status?

Unfortunately, since only less than 1% of total body magnesium is found in the serum, serum magnesium is not a good indicator of actual magnesium status, and chronic magnesium deficiency is often associated with normal serum magnesium despite deficiencies in the cell, and increased bone loss. RBC magnesium is therefore a much better indicator of current magnesium status. The optimal range for RBC magnesium is 6.0-6.5.

Talk to your healthcare provider if you wish to find your magnesium levels.

How can you improve your magnesium status via diet?

Getting adequate magnesium in the diet is a great initial approach. Magnesium rich foods also provide other essential nutrients and fiber. However, eating a ton of magnesium rich foods without proper preparation can be ineffective. Soaking and/or sprouting nuts, seeds, grains, and beans increases the bioavailability of the minerals, including magnesium. Toasting nuts and seeds helps increase bioavailability as well. 

When possible, soak your grains and beans overnight (8-12 hours), and toast or roast your nuts just before consumption. Freshly roasted nuts and seeds are best refrigerated and consumed within a week. Lightly cooked dark leafy greens are also great ways to boost your dietary magnesium intake. Below is a list of magnesium-rich foods for reference.

Food ItemServing SizeMagnesium (mg)
Quinoa1 cup cooked200mg
Pumpkin seeds¼ cup190mg
Spinach½ cup cooked from fresh180mg
Oats½ cup, dry140mg
Buckwheat grouts¼ cup, dry95mg
Almonds, roasted¼ cup100mg
Potato1 medium, boiled60mg
Swiss Chard½ cup cooked80mg
Artichoke1 medium, steamed80mg
Beans (varied)¼ cup, dry75mg
Plantain1 cup, boiled40mg
Banana1 large40mg
Molasses1 tablespoon30mg
Sesame Seeds1 tablespoon30mg

Can magnesium supplements be helpful?

Even for those individuals who eat a variety of magnesium rich foods, magnesium supplements can also be very helpful, especially if you have a low RBC magnesium. Ideally, it is best to take magnesium on an empty stomach as it competes with other minerals like calcium for absorption. Magnesium supplements in the form of amino acid chelates (like glycinate, citrate, or malate) are much more rapidly absorbed because they do not require stomach acid for absorption. Non-chelated forms like oxide, are not well absorbed and are mostly used for constipation relief.

It can take up to 40 weeks (~10 months) of consistent supplementation to reverse a magnesium deficiency. However, this even depends on other factors like continued use of magnesium wasters (coffee, alcohol, medications), dietary intake, malabsorption issues, and high-stress lifestyle. Therefore, the daily magnesium dose depends on the individual. Therefore, I highly recommend tracking your RBC magnesium levels to monitor improvement in magnesium status. However, in general magnesium has low toxicity in people with normal kidney function, and doses of 200 to 400mg, divided throughout the day, should be well tolerated.

Usually I recommend magnesium glycinate before bed because the amino acid glycine tends to have a calming effect for most people and can ease bedtime anxiety. Magnesium malate is a great option for morning supplementation because it is more energizing. If someone is struggling with constipation then magnesium citrate can be taken before bed to provide relief and support sleep. Magnesium lotions, oils, or Epsom salt baths can also be great ways to boost magnesium status transdermally and can be used any time of the day. If someone is sensitive to a particular kind of magnesium, it can be helpful to try a different chelated form.