Modern agriculture has depleted soil magnesium levels by up to 80% compared to a century ago. The foods we eat simply contain less magnesium than they used to. Combine that with diets heavy in processed food (which strips magnesium during manufacturing) and you have a population-wide deficiency.
Stress further depletes magnesium — your body burns through it during the cortisol response. Caffeine, alcohol, and certain medications also increase magnesium excretion. Standard blood tests often miss deficiency because only 1% of your body's magnesium is in the blood — the rest is in bones and tissues.
Low magnesium manifests in ways most people attribute to other causes: muscle cramps and twitches, difficulty sleeping, anxiety and irritability, brain fog, constipation, and headaches. Chronic deficiency is linked to hypertension, type 2 diabetes, osteoporosis, and cardiovascular disease.
Your heart is particularly sensitive to magnesium levels. It's essential for maintaining normal heart rhythm, and deficiency is associated with arrhythmias and increased cardiovascular risk. The brain also suffers — magnesium regulates NMDA receptors involved in learning, memory, and mood regulation.
Not all magnesium supplements are equal. Magnesium glycinate is the gold standard for sleep and relaxation — it's highly bioavailable and the glycine itself promotes calm. Magnesium L-threonate crosses the blood-brain barrier, making it ideal for cognitive function and memory.
Magnesium citrate is well-absorbed and helps with constipation. Avoid magnesium oxide — it has poor bioavailability and is mostly a laxative. For most people, 200-400mg of elemental magnesium before bed is the sweet spot. Start low to avoid digestive issues and increase gradually.
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