Early phosphorus management practices for very low birth weight infants: A survey of U.S. NICUs

We conducted an anonymous online survey between July and November 2025 using Research Electronic Data Capture (REDCap) (Supplementary material). The survey investigated hypophosphatemia practices for VLBW infants across U.S. NICUs, including parenteral nutrition practices, monitoring protocols, definitions of hypophosphatemia, methods of supplementation, and awareness of refeeding syndrome. Healthcare providers were recruited through professional networks, including the American Academy of Pediatrics Section on Neonatal-Perinatal Medicine, the Pediatrix Neonatology Forum, and the PEDI-RD listserv. Responses were deduplicated by institution, retaining only the first submission. When comparing responses from institutions with multiple submissions, no significant differences were found in key variables. Differences between NICU level and academic affiliation were assessed using Pearson’s chi-squared test or Fisher’s exact test. For more details, we followed the same methodology as a previous survey on vitamin D supplementation practices [ 4 ]. We analyzed 153 responses from 140 unique NICUs. Respondents included neonatologists (80%), dietitians (16%), pharmacists (2%), and nurse practitioners (2%), including 53% level III and 47% level IV centers (Table 1 ). Most centers (64%) were affiliated with an academic institution. Using national estimates, our survey captured 42% of level IV and 50% of academic centers across the U.S. Phosphorus was included in parenteral nutrition at 91% of centers; of the 9% not routinely including phosphorus from birth, 5% reported this was variable depending on infant factors and 4% did not routinely add phosphorus, with most (68%) initiating phosphorus within the first 1–3 days after birth, with most (68%) initiating phosphorus within the first 1–3 days after birth. The most common initial dose was 0.9–1.2 mmol/kg/day (43%), and11% reported being limited by calcium-phosphorus solubility. Most centers monitored phosphorus within the first 48 h (76%) and during the first week (84%), with non-academic centers more likely to monitor within 48 h compared to academic centers (86% vs. 70%, p = 0.039). Definitions of hypophosphatemia varied considerably, with the most common threshold being