Magnesium 101: Benefits, Food Sources, Daily Needs, and Supplement Types

Magnesium is one of the most important minerals in the human body. It plays a role in hundreds of essential processes, yet many children and adults fall short of their daily needs. In this article, you’ll learn what magnesium does in the body, how to recognize signs of low levels, which foods are rich in magnesium, and how to choose the best supplemental form when food isn’t enough.

Magnesium is a cofactor in more than 300 enzymatic reactions in the body (1). These reactions impact nearly every area of health, including:

• Nervous system regulation (2)
• Muscle function (3)
• Sleep quality (4)
• Blood sugar control (5)
• Bone strength and density (6)
• Digestive regularity (7)
• Energy production (1)

I like to use magnesium for stress support and sleep quality. I’ll go into those two topics a little deeper below.

Magnesium plays a critical role in how the body handles stress—and stress, in turn, depletes magnesium levels (8). During times of emotional, physical, or environmental stress, the body excretes more magnesium through the urine (8). Low magnesium can increase levels of stress hormones like cortisol and adrenaline, making us feel more anxious, tense, or reactive (8). This creates a feedback loop where stress depletes magnesium, and low magnesium makes stress harder to manage. Supporting healthy magnesium levels through dietary intake and/or supplementation can help improve resilience and reduce the intensity of stress-related symptoms.

Magnesium intake is associated with improved sleep duration (9) and plays a role in helping the body relax (8). Low levels of magnesium are associated with lower sleep quality (10).

Research shows that around half of Americans do not consume enough magnesium (11). Signs of suboptimal magnesium intake can be subtle and nonspecific and may include some of the following symptoms:

• Fatigue or low energy
• Irritability, mood swings, or difficulty focusing
• Trouble falling or staying asleep
• Muscle cramps or twitching
• Headaches or migraines
• Constipation
• Sugar cravings
• Restless legs
• Increased sensitivity to stress or noise

Daily magnesium requirements vary by age, sex, and life stage (1). Below are the current recommended daily intakes (RDIs):

*Adequate Intake (AI)

Too much magnesium from food is not generally a concern for healthy individuals, as excess is eliminated by the kidneys. However, high doses from supplements or medications—especially forms like magnesium oxide, chloride, gluconate, and carbonate—can cause diarrhea, nausea, and cramping. Magnesium toxicity has been reported with very large doses (typically over 5,000 mg/day) from supplements, laxatives, or antacids (1).

Magnesium is found in a variety of whole foods, particularly plant-based sources. Unfortunately, soil depletion and food processing can reduce magnesium content, even in otherwise healthy diets.

Some of the most magnesium rich foods include:

• Pumpkin seeds  
• Almonds, cashews, and other nuts
• Black beans and lentils
• Avocados  
• Spinach, Swiss chard, and other leafy greens
• Quinoa and brown rice
• Dark chocolate  
• Edamame
• Bananas

Because magnesium supplements come in many forms and not all forms of magnesium are the same, magnesium supplementation can be confusing. Choosing the right form of magnesium can make a big difference in how it’s absorbed and tolerated (12). Below are some general tips and guidelines on how to choose between different magnesium supplement types:

Magnesium is essential for hundreds of processes in the body, including stress regulation, sleep, energy production, digestion, and muscle and nerve function. Many people don’t get enough, which can lead to symptoms like fatigue, poor sleep, irritability, and muscle cramps. Whole foods like pumpkin seeds, leafy greens, and legumes are rich in magnesium. Supplementation may be helpful when needs aren’t met through diet. Choosing the right form matters—magnesium bisglycinate is especially great for stress and sleep.