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Why Magnesium?

With Samantha McKinney, RD, CPT

Season 4, Episode 14 | December 14, 2021

Magnesium is one of the most prevalent minerals in the body, impacting how we feel and function every day — yet it’s also the second most common nutrient deficiency behind vitamin D. In this mini episode, Samantha McKinney, RD, CPT, explains magnesium’s far-reaching role in our health and offers tips for making sure our bodies have optimal levels.

Samantha McKinney, RD, CPT, is a Master Trainer at Life Time who supports members and nutrition programming.

In this mini episode, McKinney offers advice for those looking to improve their magnesium status:

  • Include, but also look beyond, food sources. Dark leafy greens, beans, nuts, and legumes are all sources of magnesium and foods McKinney recommends including in a healthy diet. She notes, however, that it’s almost impossible to reach optimal levels through food alone . . .
  • Choose quality supplementation. Look for high-quality, chelated options as they’re more easily absorbed — and watch out for cheaper magnesium supplements as they can cause digestive distress. There are different forms of magnesium chelates, with McKinney’s favorites being magnesium glycinate, magnesium malate, and magnesium threonate.
  • Don’t rely on lab testing. While you can measure red blood cell magnesium, only about 1 percent of magnesium in the body is in the blood, so it doesn’t offer a complete picture. Always confirm supplement changes with your healthcare provider; generally speaking, though, magnesium is considered safe and most people can take it regularly. (If you experience loose stools, take it as a sign to scale back your dosage a little bit.)

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Transcript: Why Magnesium?

Season 4, Episode 14  | December 14, 2021

Jamie Martin

Welcome to Life Time Talks, the healthy-living podcast that’s aimed at helping you achieve your health, fitness, and life goals. I’m Jamie Martin, editor-in-chief of Experience Life, Life Time’s whole-life health and fitness magazine.

David Freeman

And I’m David Freeman, Life Time’s national digital performer brand leader. We’re all in different places along our health and fitness journey, but no matter what we are working toward, there are some essential things we can do to keep moving in the direction of a healthy, purpose-driven life.

Jamie Martin

In each episode, we’ll break down the various elements of healthy living, including fitness and nutrition, mindset and community, and health issues. We’ll also share real inspiring stories of transformation.

David Freeman

And we’ll be talking to experts from Life Time and beyond, who’ll share their insights and knowledge, so you’ll have the tools and information you need to take charge of your next steps. Here we go.


in this mini episode, we’re talking with Samantha McKinney about magnesium. Sam, welcome back to the podcast.

Thanks for having me.

Alright, so, Sam, you’re a registered dietitian and master trainer at Life Time. You support members and also the nutritional programming. So you know a thing or two about magnesium. So let’s just level set. What is magnesium? And why does it matter for our health?

So this is going to make me sound like a huge nerd. But magnesium is one of my favorite minerals. It’s one of the most prevalent minerals in the body. It’s involved in over 300 different enzymatic reactions in our body. It impacts how we feel and function every single day. And it’s actually the second most common nutrient deficiency after vitamin D. So it’s a pretty big deal.

I got some fun facts on it too. It’s number 12 on the periodic table. It’s Mg. Yeah, I took you back to school just now. Alright. Yeah. I’m pretty sure. Somebody Google it right now. But with all that, let’s list some of the benefits behind magnesium. Can you tell us some?

Yeah, I think almost starting with functions might tie into that and be a little bit better. So magnesium, it involves or it’s involved in blood sugar control. It’s involved in bone health. It’s involved in nerve conduction. That, obviously, has a lot to do with muscle control, along with your heart rate. It has a lot to do with cognition, mood. It’s hard to find a body system that’s not somehow involved in magnesium.

And whenever it comes to the benefits and functions of it, I mean, you’ve got to think, if someone’s even a little bit low, all of those systems are going to be impacted somehow. So it’s a pretty big deal. And you can imagine that there’s like a whole trickle down effect within each one of those categories that I talked about too.

Right. One of the things that you have shared before is that there are some of the benefits that we don’t feel. So you mentioned like cardiac output. What are some of those other systems that we may not realize that magnesium is involved with?

Yeah. So, well, let’s actually touch on heart health for a minute because magnesium is really involved in regulating inflammation. And so for anybody that is closely monitoring their heart health or they’re looking at inflammation pathways, one really common blood marker that more doctors are testing right now is called c-reactive protein.


And so people that are a little bit lower in magnesium tend to have higher c-reactive protein. You don’t necessarily feel that. But, obviously, with heart disease being the number one killer in terms of chronic disease, huge deal with magnesium there.

The other thing, it has a lot to do with energy production. So, yes, you might feel energy in terms of how you feel every day. But, oftentimes, people that are really focused on nutrition are thinking about macros, right? They’re talking about protein, fat, carbs. Well, for your body to actually take those macros and turn them into energy, you need magnesium. So that’s another big one.

As far as nerve function, people will tend to outwardly feel some things with nerve function, whether that be tight muscles or cramping or restless legs. But you might not feel the impact in terms of your brain because, right, your brain is a huge part of the nervous system. So cognition is super important, so quick thinking, problem solving.

The other thing is that cognition and mood as well. So I guess I’m not totally answering your question because you said things you don’t feel. But I would say things that you don’t realize necessarily.

Right. You don’t make that connection necessarily that it’s magnesium that plays a role in this versus something else that might be taking in, that you might be taking in.

Yeah. So like for mood, magnesium is needed for serotonin production, right? So that’s huge. People that might be taking, let’s say, a lot of calcium and aren’t high in magnesium, they might actually feel a little bit more like irritable and agitated. And so that’s why, oftentimes, people report, hey, whenever I take my magnesium, I just feel calmer. Like I feel a little bit more balanced. And that would be why.


So you said magnesium is pretty much the car. And the passengers are the macros, the protein, carbs, and fats, is kind of driving it to be absorbed within the body. Is that what you’re saying?

It’s not necessarily transporting it.


But magnesium in those reactions to make those passengers active and running around, it’s kind of the ticket to make that happen, if that makes sense.

That makes sense. So with that being said then, what are some types of foods that we can probably absorb and get magnesium from?

I will say that, in today’s society, you’re not going to get optimal magnesium status or very — it’s almost impossible to get it just from food. But that being said, the foods that have magnesium, you should be eating, right?


So they’re dark, leafy greens. Those have a ton of benefits. Beans are another one, nuts, legumes, pure cocoa. So I always make some friends there whenever I say, hey, your dark chocolate has some magnesium involved.

But, I mean, in reality, there are so many things that we’re exposed to that deplete our magnesium nowadays. So excess sugar intake is one. So anybody that even has slightly off-kilter blood sugars is typically going to have lower magnesium. Athletes or people that sweat a lot, their magnesium status is going to be lower.

Use of antacids is another one, so anybody with heartburn that’s taking antacids. And even if somebody is exposed to a lot of fluoride, a lot of our water fluoridated, that can lower your absorption of magnesium too. So there’s a lot of things working against us, nowadays, and then not to mention stress. Stress can deplete your magnesium levels. So if you find me someone that doesn’t work out, isn’t stress, never eats sugar, and doesn’t have any fluoridated water, then sure. Maybe the food will get them there. But I don’t know.

What’s the recommended supplement then that you would say if we’re not being able to get it through a lot of our foods because of those environmental issues there?

There’s a ton of magnesium supplements on the market. So what you want to look for is one that’s called chelated. And that’s a term in supplements that it means that they’re wrapped in amino acids. So they’re a little bit easier absorbed.

And so there are different forms of magnesium chelates. But some of my favorite ones are magnesium glycinate, magnesium malate, and magnesium threonate. So those are my three favorites.

If you take some of the cheaper forms, you are likely going to get run into the restroom real quick. Because so for someone that’s a little constipated, great. But if you take a high dose of some of the not-so-good forms, you’re going to get some digestive distress there.

And actually, on that note, I have used some of the powdered forms of magnesium in the past. And they say to really like start with a small dose for that very reason.


So start small and figure out what’s the right dose for you, is that right, until you start having those?


Is that generally or not really?

Well —

Are you looking more for milligrams? Or what are you looking for?

Yeah. I mean, it kind of depends on the form that you’re taking. So some of them, so if you’re taking like a magnesium oxide, for example, you’re going to hit that threshold way sooner than some of the chelated forms.


So, yes, you can do that. Generally, most people need somewhere between the 200 and 500 range. There are some people that need to go higher. Some need to go lower. But really, I tell people aim for around that 200 to 300 is usually the sweet spot for a lot of people.

I personally like malate. It really has a lot for the way that it functions. Every form of magnesium is a little bit different in how it helps. And malate can really help with energy production most, which is nice.

Threonate’s got some brain benefits. Glycinate’s the most well-absorbed. So each of the chelates have their own benefits. But I wouldn’t get too caught up in the weeds there. Just make sure you’re taking good chelated form in the right dose. And take it in the evening because it’s a little bit more calming too.

Is there a way to measure magnesium? Is there lab testing? Or is there any other way to know if you’re magnesium deficient?

There is lab testing. So you could look at red blood cell magnesium. But about 1% of magnesium in your body is in your blood. So generally speaking, it’s one — obviously, run it by your doctor, especially if you’re on medications or underlying medical conditions.

But I would say it’s one of the more innocuous supplements that I just generally recommend, hey, most people need to be taking this in the evening. So just take it. Obviously, if you get loose stools, scale it back a little bit, so that you don’t have that. But you’re more likely to experience benefit than any downside from it.

I heard your top three. And I’m always thinking of the pushback that I’ve seen from a lot of clients are saying, I don’t want to take all these different pills. So what about the cal-mag? Because you talked about how it helps benefit with bone density. So now you got a little bit of calcium, a little bit of mag. Is that a good option? Or?

It’s definitely an FAQ, for sure. Cal-mag, you can take both, for sure. But, more often than not, I start my clients out with just straight magnesium because they tend to be a little bit lower in that. Most people are eating some form of dairy. So they’re getting calcium in their system. If you’re eating green vegetables, you’re getting calcium too.

That being said, sometimes if I have like a postmenopausal woman and they’re a little bit more concerned about bone density then, yeah, take the cal-mag. But then watch and make sure that your magnesium dose is up to where it needs to be. So sometimes that’s going to require more capsules actually.


Awesome. Sam, anything else about magnesium before we sign off?

I would say it’s in my top recommended supplements. So if you’ve never considered it, I can’t tell you how many times I’ve looked at client blood work, for example, or people asking me for help, and it’s just so prevalent that they’re low in magnesium. So it really is a good starter place to begin. So if you’ve never done it before, take it in the evening. You’ll probably see a difference in your sleep, your just overall how calm you are, your muscle function, all of that.


Awesome. Thanks, Sam.

You’re welcome. Thanks for having me.

Thank you, Sam.


David Freeman

Thanks for joining us for this episode. As always, we’d love to hear your thoughts on our conversation today, and how you approach this aspect of healthy living in your own life. What works for you? Where do you run into challenges? Where do you need help?

Jamie Martin

And if you have topics for future episodes, you can share those with us, too. Email us at, or reach out to us on Instagram,, or @freezy30, and use the hashtag #LifeTimeTalks. You can also learn more about the podcast at

David Freeman

And if you’re enjoying Life Time Talks, please subscribe on Apple Podcasts, Spotify, Google Podcasts, or wherever you get your podcasts. Feel free to rate and review, and share on your social channels too.

Jamie Martin

Thanks for listening. We’ll talk to you next time on Life Time Talks.

Life Time Talks is a production of Life Time, healthy way of life. It’s produced by Molly Schelper, with audio engineering by Peter Perkins, and video production by Kevin Dixon, Coy Larson, and the team at LT Motion. A big thank you to the team who pulls together each episode, and everyone who provided feedback.

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The information in this podcast is intended to provide broad understanding and knowledge of healthcare topics. This information is for educational purposes only and should not be considered complete and should not be used in place of advice from your physician or healthcare provider. We recommend you consult your physician or healthcare professional before beginning or altering your personal exercise, diet or supplementation program.

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