Magnesium is involved in more than 300 enzymatic reactions in the human body. It regulates energy production, muscle function, nerve transmission, blood sugar control, and blood pressure — and it’s a key cofactor for Vitamin D activation. Despite this, surveys suggest that over half of UK adults don’t consume the recommended daily amount.
Why So Many People Are Low in Magnesium
Modern food processing removes significant magnesium from whole grains — white flour has 80% less magnesium than wholegrain. Soils are increasingly magnesium-depleted from intensive farming. Several common factors actively deplete magnesium: chronic stress (cortisol increases urinary magnesium loss), excess alcohol, diuretics, proton pump inhibitors (PPIs), type 2 diabetes (increased urinary loss), and very high calcium intake (calcium and magnesium compete for absorption).
Signs You May Be Low
The classic physical signs of frank magnesium deficiency are: muscle cramps and spasms (particularly at night), tremor, and cardiac arrhythmia. More commonly, suboptimal magnesium manifests as: poor sleep quality, anxiety and irritability, fatigue, headaches (magnesium deficiency is strongly associated with migraine), constipation, and muscle tension. Because magnesium is primarily intracellular, serum levels are an unreliable indicator of body status — you can have “normal” blood levels but still be functionally deficient in tissues.
Benefits Supported by Clinical Evidence
Sleep quality: magnesium modulates GABA receptors, which promote relaxation and sleep initiation. Multiple trials show improvement in sleep quality (particularly deeper sleep) with supplementation, especially in older adults. Migraine prevention: NICE guidelines mention magnesium as a consideration for migraine prophylaxis. Randomised trials show 400mg magnesium daily reduces migraine frequency significantly. Blood pressure: modest but consistent evidence for BP reduction. Blood glucose: magnesium is a cofactor for insulin receptor signalling; deficiency is strongly associated with insulin resistance. Correcting deficiency improves insulin sensitivity.
Choosing the Right Magnesium Form
Magnesium glycinate — the best-absorbed and best-tolerated form. Least likely to cause loose stools. Best for anxiety, sleep and muscle relaxation. Magnesium malate — good absorption; particularly useful for muscle pain and fibromyalgia. Magnesium citrate — good absorption; has a mild laxative effect that can be useful for constipation. Magnesium oxide — the most common form in cheap supplements. Very poor absorption (~4%). Mainly acts as an osmotic laxative. Not a good choice for correcting deficiency.
Browse magnesium supplements in our Vitamins range at Huncoat Pharmacy. Related: Sleep Guide, Supplements Guide.
At Huncoat Pharmacy: Magnesium IV infusion service, Browse magnesium supplements.