Magnesium is involved in over 300 enzymatic reactions in the human body and up to 50% of Americans aren’t getting enough. Here’s why it matters and what to do about it.
Signs You May Be Deficient
- Difficulty falling or staying asleep
- Muscle cramps, twitches, or spasms
- Chronic anxiety or heightened stress response
- Fatigue despite adequate sleep
- Frequent headaches or migraines
- High blood pressure
- Poor exercise recovery
Key Functions
Sleep: Magnesium activates the parasympathetic nervous system and regulates GABA — the calming neurotransmitter that prepares your brain for sleep. Low magnesium is one of the most common underdiagnosed drivers of poor sleep. See: Why Sleep Is the Most Underrated Health Tool.
Anxiety and stress: Magnesium blocks NMDA receptors activated by stress hormones and supports cortisol regulation. Multiple trials show meaningful reduction in anxiety symptoms with supplementation.
Blood sugar: Magnesium is a cofactor for insulin receptor function. People with type 2 diabetes consistently have lower magnesium levels, and supplementation improves insulin sensitivity in deficient individuals.
Cardiovascular health: Relaxes blood vessel walls, reducing blood pressure and arrhythmia risk.
Best Food Sources
- Pumpkin seeds: 168mg/oz (highest food source)
- Spinach (cooked): 157mg/cup
- Almonds: 80mg/oz
- Black beans: 120mg/cup
- Dark chocolate (70%+): 65mg/oz
- Avocado: 58mg per fruit
Should You Supplement?
If your diet is low in these foods and you experience multiple deficiency signs, supplementation is reasonable. Best-absorbed forms: magnesium glycinate (sleep/anxiety), magnesium malate (energy/muscles), magnesium threonate (cognitive effects). Avoid magnesium oxide. Standard dose: 300–400mg elemental magnesium daily, taken in the evening.
The Bottom Line
Magnesium deficiency touches every major body system. Increase dietary intake first, and consider supplementation if symptoms persist.