What are the recommended electrolyte replacements for a patient diagnosed with refeeding syndrome?

In patients diagnosed with refeeding syndrome, the recommended electrolyte replacements include potassium, phosphate, and magnesium supplementation tailored to body weight and plasma levels. Specifically, potassium should be supplemented at approximately 2 to 4 mmol/kg/day, phosphate at 0.3 to 0.6 mmol/kg/day, and magnesium at 0.2 mmol/kg/day intravenously or 0.4 mmol/kg/day orally, unless pre-feeding plasma levels are already high. Pre-feeding correction of low plasma electrolyte levels is generally unnecessary, but close biochemical monitoring is essential during the first 10 days of feeding to adjust supplementation accordingly. Additionally, thiamin (200 to 300 mg daily) and vitamin B complex should be provided to prevent complications related to vitamin deficiencies during refeeding. These electrolyte and vitamin replacements should be administered alongside cautious initiation of nutrition support, starting at no more than 10 kcal/kg/day and increasing slowly to full requirements over 4 to 7 days, with continuous clinical and biochemical monitoring to prevent and manage refeeding complications effectively NICE CG32 Matthews-Rensch et al. 2025.