Serum magnesium concentration varies with protein concentration (20-30% is protein-bound), acid-base status and carbohydrate intake (compare potassium) and thus may not reflect the total body stores.
Reference Intervals (Adult 18 yrs+):
0.70 -1.10 mmol/L
RCPA/AACB Harmonised Reference Intervals from 13/7/2015.
Age Related Reference Intervals:
< 1 week 0.6- 1.0 mmol/L
1 wk - < 18 yrs 0.65-1.1 mmol/L