Comparison 2. Magnesium versus placebo (pregnancy‐associated, idiopathic, and liver‐cirrhosis‐associated cramps): adverse effects.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
2.1 Treatment withdrawals due to adverse events	7	410	Risk Ratio (M‐H, Fixed, 95% CI)	1.17 [0.56, 2.47]
2.1.1 Idiopathic cramps (largely older adults)	3	180	Risk Ratio (M‐H, Fixed, 95% CI)	1.21 [0.34, 4.32]
2.1.2 Pregnancy‐associated leg cramps	3	201	Risk Ratio (M‐H, Fixed, 95% CI)	0.38 [0.09, 1.50]
2.1.3 Liver‐cirrhosis‐associated cramps	1	29	Risk Ratio (M‐H, Fixed, 95% CI)	6.43 [0.88, 46.92]
2.2 Minor adverse events	4	254	Risk Ratio (M‐H, Fixed, 95% CI)	1.51 [0.98, 2.33]
2.2.1 Idiopathic cramps (largely older adults)	1	94	Risk Ratio (M‐H, Fixed, 95% CI)	1.03 [0.55, 1.95]
2.2.2 Pregnancy‐associated leg cramps	2	131	Risk Ratio (M‐H, Fixed, 95% CI)	1.80 [0.97, 3.34]
2.2.3 Liver‐cirrhosis‐associated cramps	1	29	Risk Ratio (M‐H, Fixed, 95% CI)	7.47 [0.42, 132.78]
2.3 Major adverse events	3	185	Risk Ratio (M‐H, Fixed, 95% CI)	0.68 [0.14, 3.31]
2.3.1 Idiopathic cramps (largely older adults)	2	140	Risk Ratio (M‐H, Fixed, 95% CI)	0.68 [0.14, 3.31]
2.3.2 Pregnancy‐associated leg cramps	1	45	Risk Ratio (M‐H, Fixed, 95% CI)	Not estimable