Magnesium:
- 142 controls: 1.8% (range 0.5-4%)
- 74 hypomagnesemic
- Extra-Renal origin 1.4% (range 0.5-2.7%)
- Renal origin 15% (range 4-48%)
- Authors conclusion: >4% per cent is indicative of inappropriate renal magnesium loss
Potassium
- 312 normal subjects: 8% (range 4-16%)
- 84 hypokalaemic patients
- Extra-renal origin: 2.8% (range 1.5-6.4%)
- Renal origin: 15% (range 9.5-24%)
- Authors conclusion: >6.5% per cent is indicative of inappropriate renal potassium loss