Table 2.
Sex- and age-specific 2.5th and 97.5th percentiles for electrolyte levels in healthy children aged 2–14 years (n = 1391).
| Age (year) | Sex | n | Potassium (mmol/L) | Sodium (mmol/L) | Chlorine (mmol/L) | Calcium (mmol/L) | Phosphorus (mmol/L) | ||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2.5 | 25 | 50 | 75 | 97.5 | 2.5 | 25 | 50 | 75 | 97.5 | 2.5 | 25 | 50 | 75 | 97.5 | 2.5 | 25 | 50 | 75 | 97.5 | 2.5 | 25 | 50 | 75 | 97.5 | |||
| 2-<3 | M | 109 | 4.11 | 4.40 | 4.60 | 4.85 | 5.42 | 138.4 | 141.0 | 142.5 | 143.8 | 146.6 | 99.0 | 101.4 | 102.7 | 104.3 | 106.3 | 2.08 | 2.33 | 2.39 | 2.47 | 2.64 | 1.37 | 1.59 | 1.68 | 1.76 | 1.93 |
| F | 87 | 4.11 | 4.34 | 4.54 | 4.72 | 5.12 | 136.1 | 140.8 | 142.3 | 143.4 | 145.7 | 98.0 | 100.4 | 102.4 | 103.6 | 105.6 | 2.07 | 2.35 | 2.43 | 2.50 | 2.62 | 1.39 | 1.60 | 1.70 | 1.76 | 1.97 | |
| 3-<4 | M | 135 | 3.90 | 4.37 | 4.53 | 4.74 | 5.41 | 138.6 | 140.9 | 142.3 | 143.8 | 147.2 | 97.9 | 101.1 | 102.4 | 103.6 | 106.7 | 1.90 | 2.20 | 2.35 | 2.44 | 2.56 | 1.32 | 1.56 | 1.67 | 1.78 | 2.00 |
| F | 121 | 3.92 | 4.27 | 4.48 | 4.72 | 5.26 | 136.4 | 141.0 | 142.4 | 144.3 | 147.0 | 96.2 | 101.4 | 102.7 | 104.0 | 105.8 | 2.07 | 2.29 | 2.37 | 2.45 | 2.56 | 1.37 | 1.55 | 1.67 | 1.76 | 1.86 | |
| 4-<5 | M | 79 | 3.79 | 4.09 | 4.33 | 4.64 | 5.40 | 136.7 | 140.3 | 141.5 | 143.3 | 146.4 | 96.3 | 100.2 | 101.4 | 103.2 | 105.1 | 2.04 | 2.30 | 2.36 | 2.45 | 2.53 | 1.32 | 1.51 | 1.62 | 1.74 | 1.94 |
| F | 69 | 3.70 | 4.24 | 4.37 | 4.62 | 5.06 | 137.8 | 141.2 | 142.3 | 143.8 | 146.4 | 95.6 | 100.3 | 102.2 | 104.2 | 105.9 | 2.09 | 2.30 | 2.40 | 2.47 | 2.57 | 1.32 | 1.51 | 1.62 | 1.68 | 1.86 | |
| 5-<6 | M | 78 | 3.75 | 4.14 | 4.38 | 4.64 | 5.14 | 137.7 | 141.0 | 142.7 | 144.3 | 147.8 | 98.1 | 101.1 | 102.4 | 103.9 | 107.0 | 1.95 | 2.27 | 2.35 | 2.42 | 2.59 | 1.36 | 1.54 | 1.64 | 1.75 | 1.99 |
| F | 75 | 3.65 | 4.16 | 4.35 | 4.60 | 4.95 | 139.1 | 141.4 | 142.2 | 143.7 | 146.6 | 98.6 | 101.4 | 102.6 | 104.3 | 105.8 | 1.98 | 2.24 | 2.36 | 2.46 | 2.55 | 1.27 | 1.56 | 1.65 | 1.73 | 1.86 | |
| 6-<7 | M | 57 | 3.80 | 4.27 | 4.47 | 4.70 | 5.17 | 139.2 | 141.1 | 142.2 | 143.5 | 145.8 | 98.2 | 100.7 | 102.5 | 103.4 | 104.7 | 1.99 | 2.21 | 2.32 | 2.41 | 2.61 | 1.42 | 1.56 | 1.65 | 1.73 | 2.01 |
| F | 46 | 3.88 | 4.26 | 4.47 | 4.66 | 5.02 | 137.4 | 140.5 | 143.0 | 143.9 | 145.6 | 96.9 | 100.8 | 102.6 | 103.8 | 105.1 | 2.05 | 2.28 | 2.39 | 2.48 | 2.56 | 1.33 | 1.48 | 1.59 | 1.74 | 1.88 | |
| 7-<8 | M | 43 | 3.70 | 4.34 | 4.52 | 4.67 | 5.05 | 138.0 | 140.6 | 142.2 | 144.4 | 146.8 | 96.2 | 99.9 | 102.1 | 104.2 | 106.8 | 2.11 | 2.27 | 2.35 | 2.40 | 2.51 | 1.30 | 1.50 | 1.58 | 1.67 | 1.98 |
| F | 35 | 3.82 | 4.13 | 4.33 | 4.63 | 5.08 | 138.3 | 141.3 | 141.8 | 143.1 | 144.7 | 96.0 | 101.6 | 102.9 | 104.8 | 107.4 | 2.17 | 2.34 | 2.38 | 2.47 | 2.56 | 1.26 | 1.48 | 1.55 | 1.67 | 1.87 | |
| 8-<9 | M | 32 | 3.62 | 4.09 | 4.42 | 4.76 | 5.18 | 137.8 | 141.0 | 142.2 | 143.7 | 146.1 | 97.0 | 102.0 | 102.9 | 104.3 | 106.2 | 1.98 | 2.21 | 2.28 | 2.36 | 2.56 | 1.26 | 1.41 | 1.52 | 1.62 | 1.81 |
| F | 23 | 3.96 | 4.22 | 4.38 | 4.61 | 5.19 | 134.3 | 138.8 | 140.8 | 143.2 | 144.4 | 97.5 | 102.3 | 103.8 | 107.0 | 108.2 | 2.18 | 2.34 | 2.38 | 2.42 | 2.51 | 1.30 | 1.41 | 1.45 | 1.51 | 1.78 | |
| 9-<10 | M | 24 | 3.68 | 4.18 | 4.32 | 4.66 | 5.06 | 137.2 | 140.0 | 141.6 | 142.2 | 144.8 | 98.5 | 100.3 | 101.4 | 103.2 | 104.3 | 2.11 | 2.26 | 2.28 | 2.34 | 2.42 | 1.32 | 1.43 | 1.50 | 1.60 | 1.70 |
| F | 24 | 3.89 | 4.10 | 4.37 | 4.68 | 5.21 | 135.1 | 137.9 | 140.2 | 143.3 | 145.1 | 98.6 | 101.8 | 103.7 | 104.8 | 108.3 | 2.05 | 2.28 | 2.32 | 2.43 | 2.59 | 1.26 | 1.39 | 1.52 | 1.62 | 1.83 | |
| 10-<11 | M | 41 | 3.78 | 4.15 | 4.37 | 4.59 | 5.14 | 137.7 | 139.7 | 141.5 | 143.3 | 146.4 | 97.9 | 100.8 | 102.6 | 104.8 | 108.1 | 1.98 | 2.19 | 2.28 | 2.37 | 2.47 | 1.23 | 1.38 | 1.45 | 1.51 | 1.69 |
| F | 53 | 3.79 | 4.18 | 4.38 | 4.55 | 5.11 | 138.2 | 141.8 | 142.5 | 143.7 | 146.4 | 98.4 | 102.4 | 104.5 | 105.5 | 106.9 | 2.07 | 2.29 | 2.37 | 2.46 | 2.55 | 1.32 | 1.41 | 1.49 | 1.70 | 1.85 | |
| 11-<12 | M | 29 | 3.97 | 4.26 | 4.51 | 4.78 | 5.07 | 139.6 | 141.8 | 143.4 | 145.1 | 147.4 | 102.0 | 103.9 | 104.9 | 105.6 | 107.7 | 2.24 | 2.29 | 2.33 | 2.40 | 2.51 | 1.38 | 1.55 | 1.60 | 1.66 | 1.78 |
| F | 27 | 4.14 | 4.25 | 4.39 | 4.85 | 5.41 | 136.8 | 141.7 | 143.5 | 145.0 | 147.2 | 98.8 | 102.3 | 104.0 | 106.1 | 107.4 | 2.03 | 2.21 | 2.32 | 2.40 | 2.58 | 1.36 | 1.49 | 1.63 | 1.72 | 1.91 | |
| 12-<13 | M | 33 | 4.08 | 4.35 | 4.60 | 4.70 | 5.19 | 137.5 | 140.5 | 144.8 | 145.4 | 149.3 | 100.5 | 102.1 | 103.8 | 105.4 | 107.5 | 2.08 | 2.26 | 2.32 | 2.40 | 2.50 | 1.24 | 1.50 | 1.60 | 1.75 | 2.01 |
| F | 30 | 4.14 | 4.34 | 4.70 | 5.07 | 5.34 | 135.6 | 139.1 | 141.4 | 145.7 | 147.0 | 94.52 | 97.1 | 99.5 | 100.9 | 104.0 | 2.08 | 2.17 | 2.24 | 2.34 | 2.44 | 1.32 | 1.42 | 1.48 | 1.63 | 1.90 | |
| 13-<14 | M | 31 | 4.15 | 4.40 | 4.65 | 4.92 | 5.27 | 138.4 | 139.8 | 141.3 | 142.7 | 147.2 | 97.10 | 99.1 | 100.6 | 102.7 | 105.6 | 1.96 | 2.09 | 2.16 | 2.24 | 2.36 | 1.11 | 1.36 | 1.42 | 1.59 | 2.03 |
| F | 23 | 4.17 | 4.51 | 4.74 | 4.95 | 5.17 | 134.6 | 137.8 | 139.3 | 140.3 | 144.4 | 96.21 | 98.8 | 100.7 | 102.1 | 106.5 | 2.03 | 2.08 | 2.10 | 2.14 | 2.15 | 1.17 | 1.30 | 1.40 | 1.49 | 1.61 | |
| 14-<15 | M | 54 | 4.27 | 4.57 | 4.82 | 5.02 | 5.40 | 140.2 | 142.4 | 144.5 | 146.0 | 148.8 | 98.90 | 100.9 | 102.8 | 104.6 | 107.1 | 2.05 | 2.14 | 2.20 | 2.27 | 2.37 | 1.09 | 1.26 | 1.46 | 1.59 | 1.77 |
| F | 33 | 4.16 | 4.51 | 4.67 | 4.85 | 5.42 | 134.8 | 138.9 | 140.3 | 142.5 | 146.3 | 96.94 | 99.8 | 101.0 | 102.5 | 107.0 | 1.99 | 2.08 | 2.16 | 2.22 | 2.31 | 1.14 | 1.24 | 1.29 | 1.36 | 1.58 | |
M, male; F, female.