Table 1.

Key elements in magnesium deficiency.

Serum Mg Concentration	0.75–0.95 mmol/L [12]
Methods of Mg status evaluation in human body	Mg serum concentration RBC Mg levels Mg urine levels Intravenous or oral Mg loading tests Non-invasive Intracellular Mineral-Electrolyte Analysis Hair mineral analysis test Using isotopic Mg labels Ionized serum Mg concentration Serum Mg/Ca ratio [6,15,16]
Mg recommended daily allowance	Children aged 1–3: 80 mg/day Children aged 4–8: 130 mg/day Adolescents aged 9–13: 240 mg/day Girls aged 13–18: 360 mg/day Boys aged 13–18: 410 mg/day Adult women: 320 mg/day Adult men: 420 mg/day [3]
Mg deficiency symptoms	Early signs of Mg deficiency: fatigue, weakness, loss of appetite, nausea or vomiting Advanced Mg deficiency: tremor, agitation and muscle fasciculation, cramps, seizures, cardiac arrhythmia, ventricular tachycardia, personality changes or depression [25]
Mg food sources	Almonds, bananas, black beans, green vegetables (spinach, broccoli), nuts, oatmeal, seeds, brown rice, unprocessed cereals, soybeans, sweet corn, tofu, and dark chocolate [15,26]

Abbreviation: Ca, calcium; Mg, magnesium; RBC, red blood cells.