Sodium Glycerophosphate Use in Parenteral Nutrition Improves Mineral Metabolism in Extremely Low Birth Weight Infants

To evaluate the clinical effect of sodium glycerophosphate (NaGP) in parenteral nutrition solutions on mineral metabolism in extremely low birth weight (ELBW) infants.

NaGP was introduced for use in place of potassium phosphate (K₃PO₄) in January 2018; this retrospective cohort study included 95 ELBW infants treated with K₃PO₄ between January 2015 and December 2017 and 77 infants treated with NaGP between August 2018 and January 2021. Mineral intake over the first 14 days; changes in serum calcium, phosphorus, sodium, and alkaline phosphatase (ALP) levels over the first 1-3 months; and the rates of electrolyte imbalance and clinical morbidity were compared. High-risk infants who had nil per os (NPO) status for >14 days and prolonged parenteral nutrition exposure were further analyzed as a subgroup.

The use of NaGP instead of K₃PO₄ significantly increased Ca and P intake, but intakes remained below the recommended range (Ca, 64-140 mg/kg/day; P, 50-108 mg/kg/day). Compared with levels in the K₃PO₄ group, the NaGP group had significantly higher serum Ca and P levels after day 14 and lower ALP levels after day 56. In the subgroup analysis, the NaGP group had significantly lower incidences of hypophosphatemia, hyponatremia, bronchopulmonary dysplasia, and ALP >500 IU/L.

Although the administration of NaGP instead of K₃PO₄ in parenteral nutrition regimens still did not provide adequate Ca and P intake for ELBW infants, higher intake significantly improved serum Ca and P levels, especially in ELBW infants with prolonged parenteral nutrition exposure.