Version August 2025
| Electrolyte | Preterm neonates | Infants/children | Adolescent |
| Sodium | 2 to 5 mEq/kg (2 to 5 mmol/kg) | 2 to 5 mEq/kg (2 to 5 mmol/kg) | 1 to 2 mEq/kg (1 to 2 mmol/kg) |
| Potassium | 2 to 4 mEq/kg (2 to 4 mmol/kg) | 2 to 4 mEq/kg (2 to 4 mmol/kg) | 1 to 2 mEq/kg (1 to 2 mmol/kg) |
| Calcium* | 2 to 4 mEq/kg (1 to 2 mmol/kg)¶ | 0.5 to 4 mEq/kg (0.25 to 2 mmol/kg)¶ | 10 to 20 mEq (5 to 10 mmol)¶ |
| Phosphorus* | 1 to 2 mmol/kg | 0.5 to 2 mmol/kg | 10 to 40 mmol |
| Magnesium | 0.3 to 0.5 mEq/kg (0.15 to 0.25 mmol/kg) | 0.3 to 0.5 mEq/kg (0.15 to 0.25 mmol/kg) | 10 to 30 mEq (5 to 15 mmol) |
| AcetateΔ | As needed | As needed | As needed |
| ChlorideΔ | As needed | As needed | As needed |
These estimated requirements assume normal age-related organ function and normal loss.
Mmol converstions for sodium, potassium, elemental calcium and magnesium provided by UpToDate.* Guidelines recommend that for young infants (especially premature infants), calcium and phosphorus should be added in a molar ratio that is close to 1:1 to optimize phosphorus utilization. Refer to the UpToDate topic review on parenteral nutrition in premature infants.
¶ Calcium requirements above are for elemental calcium. Conversions: 1 mEq elemental calcium (20 mg) = 0.5 mmol = 215 mg calcium gluconate salt. The molecular weight of calcium gluconate is 430.373 g/mol.
Δ The ratio of acetate and chloride is adjusted as needed to maintain acid-base balance.