Magnesium (Mg) is involved in several pathways that could be affected in chronic obstructive pulmonary diseases (COPDs), namely in the contractility and excitability of neuro-muscolar endothelial cells and low-grade inflammation, a typical state of COPD. In this sense, several randomized controlled trials (RCTs) confirmed a positive role of Mg in asthma since long-period oral supplementation of Mg leads to a clinical and spirometric improvement.

Subjects with COPD seem to have a reduced bioavailability of Mg probably due to the use of drugs that may increase Mg losses (e.g. beta-agonists and cortisones), to a reduced dietary Mg intake, and heavy smoking. A recent study showed that the administration of endovenous or aerosol Mg sulphate with beta-agonists acutely improve maximum expiratory flow during COPD relapses as well as the prolonged treatment with endovenous sulphate Mg led to a reduction in pulmonary hyperinflation and increase in muscles involved in respiration, with a consequent clinical and instrumental improvement.

These evidences suggest that a chronic supplementation with Mg could improve COPD in clinical and instrumental parameters, but, at the best of our knowledge, no study was available in this sense.

Inclusion Criteria:

• Adults (>18 years).
• Moderate-severe COPD (FEV1 between 30-80% of theorical values).

Exclusion Criteria:

• Already taking magnesium or calcium supplementations.
• Severe renal (creatinine clearance< 30 ml/min) or hepatic decline or presence of other co-morbidities interfering with outcomes (e.g. dementia).
• Hypermagnesemia (serum Mg>1.85 mmol/L).