Magnesium

Magnesium is an essential ion in the human body that regulates numerous physiological and pathological processes. ^[1] It is the fourth most abundant cation in the human body and a critical cofactor in hundreds of enzymatic reactions that regulate energy metabolism, neuromuscular function, cardiovascular health, and bone integrity. ^[2] As part of the Mg-ATP complex, magnesium is involved in over 600 enzymatic reactions, and serum levels are tightly regulated between 0.7 and 1.1 mmol/L by intestinal absorption and renal excretion. ^[3]

Magnesium is essential for energy metabolism, muscle contraction, and neurotransmission. ^[3] Chronic magnesium deficiency results in excessive production of oxygen-derived free radicals and low-grade inflammation, and magnesium acts as an antioxidant against free radical damage of the mitochondria. ^[4] Hypomagnesemia, defined as serum magnesium below 0.7 mmol/L, develops when intestinal or renal magnesium absorption is disturbed, with common causes including alcoholism, type 2 diabetes, and drugs such as proton-pump inhibitors and thiazide diuretics. ^[3]

Magnesium deficiency remains common worldwide, driven by inadequate dietary intake, chronic diseases, medication use, and lifestyle factors, and low magnesium status is associated with hypertension, type 2 diabetes, osteoporosis, migraines, depression, and chronic inflammation. ^[2] Over the past 20 years, epidemiological studies, randomized controlled trials, and meta-analyses have found an inverse relationship between magnesium intake or serum magnesium and cardiovascular disease, including hypertension, stroke, and cardiac mortality. ^[5] Controlled human depletion-repletion experiments found that mild or moderate magnesium deficiency can cause physiological and metabolic changes that respond to magnesium supplementation. ^[5] A systematic review and meta-analysis of three randomized controlled trials in 151 older adults found that oral magnesium supplementation reduced sleep-onset latency by 17.36 minutes compared with placebo, though all trials were at moderate-to-high risk of bias and the evidence was of low to very low quality.

Magnesium deficiency is very common in old age, and changes in magnesium metabolism with aging include diminished intake, impaired intestinal absorption, and renal magnesium wasting. ^[8] Magnesium is related to all the hallmarks of aging, and maintaining an optimal magnesium balance throughout life may be a safe and economical strategy contributing to healthy aging, though this needs to be demonstrated by future studies. ^[1] A large number of individuals routinely consume less magnesium than the estimated average requirement, making inadequate magnesium status a nutrient of public health concern that is a modifiable factor with potential to lessen the burden of chronic diseases. ^{[5] [2]}