5 Myths About Eating (and Taking) Magnesium for Wellness, Debunked by RDs Who Know Better

That said, intentionally fueling your body and practicing gentle nutrition, or adding nutrient-rich foods to your plate, can be beneficial for many. It’s just that sometimes, NutritionTok (for starters) takes it too far. On the menu today to debunk? The biggest myths you may have heard about magnesium and magnesium deficiency, as well as truths behind them, according to health experts.

5 magnesium myths to move on from

Myth: Getting magnesium through your skin is more effective than oral supplements

Yep, magnesium sprays, flakes, and salt baths exist—but they "aren’t the answer," says Kelsey Costa, MS, RDN, a registered dietitian and nutrition consultant for the National Coalition on Healthcare.

“The claim that magnesium absorbed through the skin (transdermal) surpasses oral supplements in effectiveness isn’t backed by solid, scientific evidence,” Costa says, pointing to a 2017 study in Nutrients that also “cannot yet recommend the application of transdermal magnesium.” Further, she believes the hype around this trend is driven by marketing campaigns, not science.

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Myth: Oral supplements are the best route for getting more magnesium

While oral supplements can be helpful, they're also not necessarily the best route. “Some of the best magnesium-rich foods are nuts and seeds such as almonds and cashews, cooked spinach, and baked potatoes with skin,” says Sarah Schlichter, MPH, RDN, a registered dietitian with Nutrition for Running.

And getting enough magnesium is important for your sleep, gut health, and other parts of your health.

“Some of the best magnesium-rich foods are nuts and seeds such as almonds and cashews, cooked spinach, and baked potatoes with skin.”
—Sarah Schlichter, MPH, RDN

Myth: Everyone is at risk for magnesium deficiency, so we should all take supplements

To be clear, magnesium is a vital mineral, and nearly half of Americans consume less than the estimated average requirement, Costa shares. At the same time, she believes “it’s not accurate to claim that everyone is universally deficient and requires supplementation.”

Side note: Those who have certain chronic illnesses, take certain medications, don’t eat many magnesium-rich foods (like dark leafy greens, whole grains, nuts, and legumes), and who drink heavily are at a higher risk of deficiency, Costa adds, referencing the study linked above as well as one in Open Heart. Some examples of those medications include diuretics, chemotherapy drugs, and aminoglycoside antibiotics.

Unfortunately, testing might not always give you the right answer on whether you’re deficient, either. “Routine blood tests may not always reflect an accurate magnesium status as the mineral is mainly stored in tissues and bones, and certain types of deficiency may still show normal blood levels,” Costa explains.

Myth: Body odor is a sign of magnesium deficiency

These two simply shouldn’t be equated, according to Schlichter.

Jaclyn London, RD, a registered dietitian, agrees. She posted a duet on TikTok with another creator who claimed her body odor signaled she was deficient in magnesium. Further, the creator made a magnesium water spray to use instead of “cancer-causing deodorant” (*cough cough* another myth!).

@jaclynlondon #duet with @Ali is Toxin Free #magnesium PLEASE DON’T fall for crazy 💩like this!! (And if you don’t smell great today, well…maybe let’s just start with a sensible shower & see where we land.???) Here’s the deal: You’re probably NOT magnesium deficient. Here’s why 👇 •Inadequate intake of magnesium is very common— >50% of U.S. adults aren’t getting enough (PMID: 29387426)… •…but symptoms of acute magnesium DEFICIENCY are actually pretty rare. That’s b/c our bodies store magnesium in bones & soft tissue cells (about 25g), & &lt1% of total body magnesium is stored in blood serum levels that are tightly regulated by your kidneys. In other words: Even if you have low magnesium levels on a blood test, that doesn’t tell you much about your body’s own total magnesium status (since a blood test is only measuring that 1% serum magnesium). •For most generally healthy people: Maintaining magnesium homeostasis=your kidneys will naturally excrete less urine if/when serum magnesium is super low, as they do in response to low levels of all electrolytes (including sodium, potassium, & chloride). •Symptoms of actual, acute magnesium deficiency are extremely serious, & include loss of appetite, nausea, vomiting, fatigue, & weakness, & can progress into numbness, tingling, muscle cramps/contractions, & abnormal heart rhythms. It can also cause other severe mineral deficiencies (potassium,, calcium), since your body’s trying to regulate/establish normal electrolyte levels in your blood stream. •People at risk= anyone who’s experienced severe GI losses due to chronic conditions (Crohn’s, Celiac Disease); ppl w/ type 2 DM, older adults, & ppl w/ chronic alcohol dependence. Bottom line: Despite what’s all over the internet, I’m really not concerned you’re at risk for severe magnesium deficiency— it’s unlikely at best. HOWEVER… •You may be at risk for magnesium inadequacy due to not consuming enough magnesium-rich foods. Since this can increase your risk of chronic disease such as hypertension, diabetes, & osteoporosis, here’s where I’d suggest you start: 🥑Eat more leafy greens; nuts & seeds; peanuts & legumes; seafood & 100% whole-grains— DM me if you want a more specific list of high Mg foods 🥑If you’re still concerned you’re not getting enough: Consult your PCP before you go supplement shopping, please! 🥑Choose a dietary supplement that meets your needs/lifestyle, & is third-party tested for ingredient verification & safety. 👉Any questions? LMK in the comments 👉Follow for more nutrition tips, food product picks & wellness myth-busting 👉Save & share w/ someone who needs to hear this #dietitian #magnesiumdeficiency #mythbusting #dietmyths #dietmythsdebunked #nutritionmyths #nutrientdeficiency #foodfirst ♬ again - floreaudios

In the caption, London also clarified that while an inadequate intake of magnesium is common, an actual deficiency is rare.

Schlichter adds more typical symptoms of magnesium deficiency are fatigue, nausea, weakness, and loss of appetite.

Myth: Consuming too much magnesium-rich foods can lead to toxicity and serious health problems

This myth has a caveat, like some of the others. “While it’s possible to consume too much magnesium, it’s highly unlikely through diet alone,” Costa says. “The kidneys are efficient at regulating levels of magnesium in the body, and excess amounts are excreted in urine.”

That said, if you do take supplements, be careful—and always consult a medical professional prior to starting any new supplement routine. “Large doses of magnesium, especially in amounts exceeding 350 milligrams per day, can potentially lead to harmful consequences,” Costa adds. Some of the consequences she notes are irregular heartbeat, low blood pressure, confusion, and other conditions that can be fatal.

All of this comes down to a couple of core messages: Every person’s body is different with various needs, and consider thinking twice when you read health advice on social media—especially if it’s attached to a product.