Magnesium - should you supplement?

Magnesium is all the rage right now, is there science to support the hype?

When I learned that 50% of Americans don’t get enough magnesium, yet this mineral is involved in over 300 different biological functions in our bodies, I had to do some investigating.¹ Especially when it seems like everyone and their grandmother is popping a magnesium supplement on social media right now… 

Magnesium is involved in energy production, nerve function, DNA synthesis, liver detoxification, and more. So there is no doubt it is an essential nutrient - but can we just increase our intake through diet? Or should we all jump on the supplement train?

If you have poor blood sugar control, insulin resistance, low mood, anxiety, poor sleep, poor liver detoxification, or high blood pressure, you might find this article interesting. As usual, this article is general education and not to be taken as medical advice - always work with your doctor. 

Health Benefits - What the Studies Show

Perhaps the most compelling study I came across on magnesium is this: a 2016 study combined results from over 1 million patients and found that a simple 100mg increase in magnesium in the diet was associated with² :

• 22% lower risk of heart failure

• 7% lower risk of stroke

• 19% lower risk of type 2 diabetes

• 10% lower risk of dying from any cause 🤯🤯🤯

100mg increase in magnesium in the diet is not hard to do, in my next substack, I will send you 3 of my favorite recipes to help you do this. 

When I dug deeper, I found other decent studies that showed magnesium could be beneficial for: high blood pressure, type 2 diabetes, metabolic syndrome (high blood sugar, high cholesterol, belly fat, high blood pressure), sleep, constipation, anxiety and mood, if you are a nerd like me, here is the deep dive: 

1. Hypertension

A meta-analysis of around 2,000 participants showed that taking magnesium was associated with lower blood pressure. The amount of reduction varied, but when they removed the lower-quality studies from analysis, they found an average drop of 3.4mmHg systolic and 2.5mmHg diastolic.³ So, it is not a magic pill for high blood pressure by any means, but it may play a small part if someone is deficient. High blood pressure is multifactorial, so working on other root causes like lifestyle factors and diet is important. Consider meds if you can’t keep it under control as it’s a risk factor for cardiovascular diseases.

2. Metabolic Syndrome

Diagnosable when you check 3 of the following: high blood pressure, high blood sugar, high cholesterol, and belly fat. This increases the risk of diabetes and cardiovascular disease. A 2016 meta-analysis of nearly 32,000 participants found that lower dietary intake of magnesium was associated with a 27% increased risk of having metabolic syndrome.⁴

3. Type II Diabetes

A meta-analysis including 638,000 patients found that per 100mg/day increase of dietary magnesium intake was correlated with an 8-13% reduction in risk of developing type II diabetes.⁵ 

4. Bone Health

A 2023 study involving 120,000 patients found that people with lower serum magnesium were 1.6 times more likely to suffer incidental fractures. I’m not saying low magnesium causes bone fractures, but it may play an important role in vitamin D and also bone health.⁶

5. Chronic Constipation

Magnesium salts have been shown to be effective at relieving constipation. A randomized controlled trial demonstrated that 1.5g of magnesium oxide was significantly more effective than a placebo at improving constipation in Japanese adult female patients.⁷ A 2023 randomized controlled trial involving 40 children (6 months to 18 years) found that Polyethylene glycol and magnesium oxide (milk of magnesia) were equally effective at relieving constipation, although PEG was better tolerated.⁸

6. Sleep

I have seen a sudden interest in taking magnesium to help improve sleep, but there is nuance here, and it might not help everyone. Five out of eight studies in a systematic review in 2024 found a positive effect from magnesium supplements.⁹ The effects ranged from time asleep, time taken to fall asleep, and quality of sleep.

Contrary to popular belief on social media, which says don’t take magnesium oxide as it’s inferior - four out of five studies using magnesium oxide reported a positive effect. So, if money is tight, supplementing with magnesium oxide ‘may’ still work. If money is not a concern, using chelated forms like glycinate or threonate (see below) may work better.

7. Anxiety & Mood

Five out of the seven included studies in the systematic review mentioned above also reported a positive effect on anxiety scores after using magnesium supplements. Two of the studies with the greatest reduction in anxiety scores included pyridoxine (vitamin B6), an important cofactor in the production of serotonin, which regulates our mood. The authors concluded that supplemental magnesium is likely useful in the treatment of mild anxiety and insomnia, particularly in those with low magnesium status at baseline. Optimal Magnesium PLUS from Seeking Health has magnesium combined with pyridoxine, but don’t take this if you are getting pyridoxine from another supplement e.g. a multi, as you might get too much (P.S. This is not the one I take, I mention it as an example if your diet is low in pyridoxine).

Work with your doctor if you want to use magnesium for any of the above conditions as everyone is different and this article is purely educational and not meant to be medical advice. 

How to Get Enough Magnesium

Part of the problem with magnesium deficiency or insufficiency is that it can be difficult to detect. 

Our body stores around 25g of magnesium, however, 90% of the body’s magnesium is stored in our bones and muscle mass, and only 1% is in our bloodstream. For this reason, I use Red Blood Cell Magnesium when testing patients and clients for magnesium (and not serum magnesium levels).

The RDA (Recommended Dietary Allowance) of magnesium is:

• 420mg for men

• 320mg for women (but increases during pregnancy)

But we may need more! A 2021 study suggested that these values were calculated using the average body weight for Americans in 1997, instead of the current average body weight, which is much higher.¹⁰

In addition, we also lose magnesium through:

• Sweating

• Vomiting & diarrhea

• High refined sugars in our diet

• Excessive alcohol intake

• Certain medications e.g. diuretics, long-term use of proton pump inhibitors like Nexium, Prilosec

We also use up more magnesium when we are stressed (and who isn’t stressed these days?).¹¹

Getting Magnesium through our diet

I shoot for 500mg of magnesium a day via either diet alone or diet with a supplement. This is what’s right for me based on years of tracking my own labs, and I’m not telling you this will work for you. I don’t have a deficiency, and if you do, you may need a different amount. Also, so many factors play into how much magnesium someone needs e.g. blood sugar, medications/medical conditions, etc - so my goal here, as always, is to provide information so you can make use it to make informed decisions on what will work for you with your own doctor.

Getting magnesium through the diet is better than supplementing because it usually comes bundled with co-factors and other minerals that help our bodies use it.

High Magnesium foods I Include daily:

• Leafy greens: ½ cup of boiled spinach provides 78mg (19% Daily Value).

• Seeds: My favorite is sprouted pumpkin seeds. Just 1 serving (1 oz) of pumpkin seeds contains 156mg (37% Daily Value). Chia seeds are another favorite, coming in at 111mg of magnesium (26% of Daily Value) with just 1 serving (1 oz). 

• Nuts: 1 oz of almonds contains around 80mg magnesium (18% Daily Value); 1 oz of oil-roasted peanuts contains 63mg magnesium (15% Daily Value).

• Other sources I love: Black Beans, Organic Edamame, Organic Soy milk, Avocado, and last but not least, perhaps my favorite - dark chocolate. 

How much is being absorbed?

You are not what you eat but what you absorb. 

It is estimated that only 30-40% of magnesium in food is absorbed, and it is best done in small amounts over time rather than all in one big hit. 

So, including magnesium-rich foods in each of your three meals is a good idea.

Oxalate and phytic acids can reduce magnesium absorption, but here are some helpful ways to counteract these: 

• Counteract Oxalates by cooking it. For example, spinach is high in oxalates. But cooking significantly reduces this - so cook your spinach if you want to maximize magnesium bioavailability.¹²

• Counteract Phytic acid by soaking & sprouting, or fermenting:

  • When buying grain-based products like bread, opt for slow-fermented sourdough. The slow fermentation process helps break down the phytic acid. 

  • Choose sprouted nuts and seeds 

  • Soak your beans overnight before cooking them

  • Include vitamin C with these foods – just 30mg of ascorbic acid has been found to counteract the phytic content and improve the absorption of magnesium.¹³ Luckily, most plant foods that are high in magnesium also come packed with vitamin C. Isn’t nature smart? 

If you have GI conditions like inflammatory bowel disease, your magnesium requirement may be higher due to poorer absorption - speak with your doctor. 

Choosing the Right Magnesium Supplement

I’m a big advocate of using food as medicine, however, after all my reading and digging, I’ve personally decided to incorporate magnesium supplements into my routine 3-4 times a week, especially if I am super stressed or not eating my usual diet.

Let’s dive into the various forms and what I take…