Earlier research has shown a relationship between low magnesium levels and the development of asthma. Intravenous magnesium has also been used in emergency settings to help stop acute asthma attacks.
Research appearing in the Journal of Asthma (2010;47(1):83–92) examined the effects of oral magnesium supplementation in patients with asthma. The study included 52 men and women between the ages of 21 and 55 who had been diagnosed with mild to moderate asthma. Subjects were given either a placebo or 340 mg of magnesium citrate daily for six and a half months.
The group receiving magnesium experienced significant improvements in lung function and airflow. Participants taking magnesium also reported an improved quality of life compared to those in the placebo group. Levels of C-reactive protein (CRP), a marker of inflammation, were similar in both groups. Serum magnesium and intracellular magnesium levels were also similar between the magnesium and placebo groups.
These findings suggest that magnesium supplementation may improve lung function and symptoms in people with mild to moderate asthma, even when standard blood markers of magnesium status and inflammation do not change.
One limitation of many magnesium studies is the reliance on serum magnesium levels, which are a poor indicator of total body or intracellular magnesium status. Magnesium is largely an intracellular mineral, and serum levels are maintained at the expense of tissue stores. As a result, clinically meaningful magnesium deficiency may be present even when serum values fall within the normal range. This distinction is important when interpreting studies that show clinical benefit from magnesium supplementation without changes in serum magnesium.
