As pharmacists, we're trained to focus on the biochemical heavyweights—sodium, potassium, and calcium. Yet one essential mineral often remains in the shadows despite its involvement in more than 300 enzymatic reactions throughout the body: magnesium.

From energy production and DNA synthesis to muscle function and nerve conduction, magnesium plays a critical role in maintaining health. Despite its importance, magnesium deficiency is surprisingly common. Estimates suggest that at least 20% of the population may be deficient, while many more experience subclinical low magnesium levels that often go undetected. Modern agricultural practices, food processing, dietary habits, and medication use all contribute to this growing concern.

The Medication Connection: A Hidden Cause of Magnesium Depletion

One of the most overlooked contributors to magnesium deficiency is medication use. Many drugs commonly dispensed in pharmacy practice can gradually deplete magnesium stores, often without obvious warning signs.

Proton pump inhibitors (PPIs), for example, can reduce intestinal magnesium absorption and have been associated with severe hypomagnesemia during long-term use. Likewise, loop and thiazide diuretics increase renal magnesium losses, potentially worsening muscle cramps, weakness, or even cardiac arrhythmias in susceptible patients.

Other medications known to affect magnesium status include:

Aminoglycoside antibiotics
Cisplatin and certain chemotherapy agents
Oral contraceptives
Chronic use of high-dose laxatives
These drug-induced depletions can be especially problematic in patients who are already at higher risk, including older adults, individuals with diabetes, those with poor dietary intake, and patients with chronic gastrointestinal disorders.

Why Magnesium Deficiency Is Often Missed

Identifying magnesium deficiency isn't always straightforward. Since only about 1% of total body magnesium is found in the bloodstream, serum magnesium levels may remain normal until deficiency becomes significant.

While red blood cell (RBC) magnesium testing may provide a better reflection of overall magnesium status, it is not commonly ordered in routine practice. As a result, pharmacists and healthcare providers often need to look beyond laboratory values and consider clinical presentation.

Potential signs of magnesium insufficiency include:

Muscle cramps or spasms
Fatigue and low energy
Insomnia or poor sleep quality
Heart palpitations
Constipation
Headaches or migraines
Recognizing these symptoms—particularly in at-risk patients—can help uncover deficiencies that standard blood work may miss.

Food First: The Foundation of Magnesium Optimization

Whenever possible, I encourage a food-first approach. Magnesium-rich foods offer not only the mineral itself but also a wide range of complementary nutrients that support overall health.

Excellent dietary sources include:

Leafy green vegetables
Nuts and seeds
Legumes
Whole grains
Dark chocolate
For many individuals, improving dietary intake can significantly enhance magnesium status. However, there are situations where supplementation becomes necessary.

Not All Magnesium Supplements Are Created Equal

One of the most common misconceptions about magnesium supplementation is that all forms provide similar benefits. In reality, absorption and tolerability can vary considerably.

Organic Magnesium Salts: Better Absorption, Better Results

Organic forms of magnesium generally offer superior bioavailability and are often preferred when treating systemic symptoms such as muscle cramps, fatigue, and sleep disturbances.

Examples include:

Magnesium bisglycinate (glycinate)
Magnesium lactate
Magnesium malate
Magnesium L-threonate
Magnesium L-threonate has garnered attention for its ability to cross the blood-brain barrier more effectively than other forms and may provide additional benefits for patients experiencing migraines or certain neurological concerns.

Personally, magnesium bisglycinate remains my preferred option. It combines excellent bioavailability, reasonable cost, and gentle gastrointestinal tolerability, making it a practical choice for many patients.

Inorganic Magnesium Salts: Useful for the Right Patient

Inorganic magnesium salts, including magnesium oxide, hydroxide, and sulfate, are generally less expensive but are also less efficiently absorbed.

Because more magnesium remains within the gastrointestinal tract, these forms are more likely to cause diarrhea and other GI side effects. While this can be problematic for some patients, it can be advantageous for those seeking relief from constipation.

Selecting the appropriate magnesium formulation should always be guided by the patient's symptoms, goals, and tolerance.

A Small Mineral with Big Clinical Impact

Magnesium may not receive the same attention as some of its mineral counterparts, but its clinical significance is difficult to overstate. Optimizing magnesium status may support better sleep, help reduce muscle spasms, ease menstrual discomfort, assist with blood sugar regulation, and improve overall well-being.

As pharmacists, we are uniquely positioned to identify risk factors for deficiency, recognize drug-induced nutrient depletions, and provide evidence-informed recommendations on both dietary and supplemental magnesium.

Perhaps it's time this hardworking mineral received a little more recognition. By bringing magnesium into the therapeutic spotlight, we can help patients address a common but frequently overlooked contributor to their health concerns—and potentially make a meaningful impact with a relatively simple intervention.

 

By: Dora Chan, PharmD, MS (Nutrition & Functional Medicine) Doctor Dora Nutrition & Wellness – doctordora.com