4 Dietitians Share the One Supplement They Trust

Reviewed by Dietitian Katey Davidson, M.Sc.FN, RD, CPT

Key Points

• Dietitians suggest magnesium supplements when dietary sources are insufficient.

• Magnesium plays a crucial role in sleep and muscle function, underscoring its importance.

• Individual magnesium needs differ, so consulting with a healthcare professional is recommended.

Nutrition should ideally come from food, yet even the most qualified experts can experience nutritional shortcomings. Registered dietitians dedicate their careers to promoting healthy eating, so it may come as a surprise that many still rely on supplements to address these gaps.

While individual needs can vary significantly, certain supplements stand out as particularly beneficial because some nutrients can be challenging to obtain solely through diet. Four dietitians shared that the one supplement they take daily is magnesium. Read on to discover why magnesium is frequently recommended and what you should consider before trying it yourself.

Why Dietitians Take Magnesium

Magnesium is a vital mineral involved in numerous bodily functions, from supporting muscle and nerve activities to regulating blood sugar levels. It’s found naturally in a range of foods such as nuts, seeds, leafy greens, legumes, and whole grains. Unfortunately, many people do not consume these foods frequently enough.

This dietary shortfall means that nearly half of Americans do not meet the daily intake recommendations—400–420 milligrams (mg) for men and 310–320 mg for women, according to Elizabeth Ward, M.S., RDN.

Ward identified this deficiency as her motivation for starting magnesium supplementation. “I began taking it because I noticed I wasn’t meeting my daily magnesium needs through food alone.”

Besides addressing nutrient gaps, dietitians provided several other motivations for daily magnesium intake. One prominent reason is improved sleep quality. Magnesium aids in regulating gamma-aminobutyric acid (GABA), a neurotransmitter that helps soothe the central nervous system, making it easier to relax and enhance sleep. As dietitian Lisa Moskovitz, RD, CDN notes, “When I take it at night, I wake up feeling more refreshed and experience better quality sleep.”

The benefits of magnesium extend beyond sleep. It also contributes to muscle and nerve function. Megan Huff, RDN reports a significant improvement: “I started taking magnesium glycinate to alleviate restless legs and leg cramps, and I haven’t had either issue for two years!”

For Ashley Kitchens, M.P.H., RD, the reason for supplementation was athletic recovery. “As a CrossFit athlete training five days a week, I added magnesium to support muscle function and recovery.”

Who Is Most Likely to Benefit

While magnesium can benefit many, dietitians believe that certain groups may particularly gain from supplementation:

• Athletes and Very Active Individuals: Regular exercisers and those who perspire profusely may have heightened magnesium needs. “Magnesium loss through sweat is common, and it’s vital for muscle contraction and recovery,” explains Kitchens.

• Older Adults: As we age, our bodies become less efficient in absorbing magnesium from food, making supplementation potentially advantageous, according to Kitchens.

• People with Sleep Difficulties: “Those who struggle with disrupted sleep or wake up feeling unrefreshed are likely to benefit from magnesium,” states Huff. It’s essential to recognize that underlying health concerns might also affect sleep quality and should be discussed with a healthcare provider.

• Individuals with Low Magnesium Intake: Those who do not consume a sufficient amount of magnesium-rich foods due to dietary restrictions or selective eating might not get enough. Collaborating with a registered dietitian can help enhance food choices and assess the necessity of supplementation.

Who Should Use Caution

Although magnesium supplements are generally safe, certain groups should consult with their healthcare provider before starting supplementation.

People with chronic kidney disease should particularly exercise caution. Healthy kidneys flush out excess magnesium, but when kidney function is compromised, magnesium can accumulate to potentially harmful levels, warn Kitchens and Huff.

Huff also points out that individuals with myasthenia gravis—an autoimmune disorder leading to muscle weakness—should seek professional advice before taking magnesium supplements. Given that magnesium has a muscle-relaxing effect, it might exacerbate symptoms in some cases.

Potential Side Effects

While magnesium supplements are generally well-received, the most common side effects involve digestive issues. “High doses of magnesium—especially from supplements or medications such as laxatives and antacids—can lead to diarrhea, nausea, and cramping,” explains Ward. She specifically warns that magnesium oxide is particularly known to cause digestive distress.

To reduce these symptoms, Kitchens recommends beginning with a lower dosage and adjusting as needed. She recounts a personal experience of digestive discomfort after taking too high a dose before bedtime.

In extreme cases, very high doses may result in more severe issues, such as low blood pressure or an irregular heartbeat, according to Kitchens.

Ward further cautions that magnesium supplements can affect the efficacy of certain medications, including antibiotics and treatments for osteoporosis. Therefore, it’s crucial to inform your healthcare provider and pharmacist about any supplements you are taking.

What to Look for When Buying Magnesium

Not all magnesium supplements are equal. Dietitians recommend focusing on several essential factors when selecting one:

• Choose a Well-Absorbed Form: Options like magnesium glycinate (or bisglycinate) and magnesium malate are usually well absorbed and gentle on the stomach. Alternatively, magnesium oxide is less bioavailable and tends to cause digestive discomfort.

• Match the Form to Your Goal: “Identify your objective for taking magnesium to choose the best form aligned with your needs,” advises Moskovitz. For example, magnesium citrate is often selected for its mild laxative properties, while magnesium glycinate is preferred for sleep and muscle support.

• Follow Dosing Instructions: The upper limit for supplemental magnesium is 350 mg daily for adults. Exceeding this dosage should only be done under the guidance of a healthcare provider, according to Ward.

• Look for Independent Testing: To ensure quality, Huff recommends choosing supplements verified by a reputable independent organization such as NSF International, USP, or Informed Choice.

• Watch for Misleading Claims: “Be cautious of vague labeling and companies making broad health claims without scientific backing,” warns Kitchens.

• Be Cautious with Added Ingredients: Huff suggests avoiding products with proprietary herbal mixtures or additional nutrients that might interact with other medications or lead to excessive intake when combined with other supplements. In many cases, a simple magnesium-only supplement is the best and safest option.

Our Expert Take

While dietitians typically advocate for a food-first approach to nutrition, supplementation can be beneficial for filling nutritional gaps in some situations. With nearly half of adults falling short of the daily recommended magnesium intake from food alone, it’s understandable why many dietitians choose this supplement and often endorse it.

Nonetheless, not everyone requires magnesium supplementation, and more is not always better. Individual needs can differ based on dietary habits, health status, and lifestyle. For these reasons, consulting a healthcare provider to determine the correct approach for you is essential.

Read the original article on EatingWell