Effect of phosphorus intake in total parenteral nutrition infusates in premature neonates

Area of Science:

• Neonatal Medicine
• Pediatric Nutrition
• Biochemistry

Background:

• Critically ill neonates often require total parenteral nutrition (TPN).
• Accurate assessment of nutrient requirements, including phosphorus (P), is vital for this population.
• Previous recommendations for P intake in neonates receiving TPN lack specific guidance for critically ill infants.

Purpose of the Study:

• To evaluate the effects of varying phosphorus intake levels on critically ill neonates receiving TPN.
• To identify an appropriate phosphorus dose that prevents both phosphate depletion and secondary hyperparathyroidism.

Main Methods:

• A study involving 27 appropriate weight for gestational age, critically ill neonates requiring TPN for 2 weeks.
• Participants received approximately 30 mg/kg/d of elemental calcium.
• Three groups received low (1.01 mmol/kg/d), moderate (1.34 mmol/kg/d), or high (1.67 mmol/kg/d) phosphorus intake.

Main Results:

• The low P intake group exhibited signs of phosphate depletion, including hypercalciuria, hypophosphatemia, and absence of phosphaturia.
• The high P intake group showed high urinary cyclic adenosine monophosphate excretion and phosphaturia, indicative of secondary hyperparathyroidism.
• The moderate P intake group demonstrated neither phosphate depletion nor secondary hyperparathyroidism.

Conclusions:

• A moderate phosphorus intake of 1.34 mmol/kg/d (40 mg/kg/d) appears to be appropriate for critically ill, poorly growing neonates receiving TPN.
• This dosage effectively balances the prevention of phosphate depletion and secondary hyperparathyroidism.
• Further research may refine optimal P management strategies in this vulnerable population.