Risk Factors

• <30 weeks gestation.
• <1000g birthweight.
• Delayed establishment of full enteral feeds/prolonged parenteral nutrition.
• Enteral feeds with low mineral content or bioavailability (unfortified EBM, standard term formula).
• Chronic use of medications that increase mineral excretion (diuretics, dexamethasone, sodium bicarbonate).
• Cholestatic jaundice.

When an infant is identified to be at risk of osteopenia, measurement of urinary mineral excretion and serum 25-OH D should be considered.

Guidelines for the Treatment of Osteopenia of Prematurity

1. Prescribe elemental calcium 2.5mmol/kg/day and elemental phosphate 1.6mmol/kg/day to be given in divided doses, four times daily. 
   Calcium and phosphate must not be given at the same time, so in practice should be given at alternate feeds.  
   For example,

   0600hr		Calcium 1.25mmol/kg/dose
   1200hr		Phosphate 0.8mmol/kg/dose
   1800hr		Calcium 1.25mmol/kg/dose
   2400hr		Phosphate 0.8mmol/kg/dose

   As intestinal obstruction has been associated with calcium supplementation of enteral feeds, incremental advancement of calcium and phosphate supplements is recommended starting at 50% of the target dose recommended above.
   Contact the Newborn Unit Pharmacist for directions.

2. Ensure an adequate intake of calcium and phosphate from feeds:
   • If <3.5kg Fortified EBM or Preterm formula
   • If >3.5kg Unfortified EBM or Term formula (not Soy)
   • N.B. This is different from the usual recommendation of 2.5kg.
3. Ensure a daily intake of 400IU Vitamin D per day.
   • If on Fortified EBM or Preterm formula - Vitadol C 0.15ml/day (note this is different to usual recommendations)
   • If on Unfortified EBM or term formula - Vitadol C 0.3ml/day 
4. Weekly monitoring in infants being treated with additional calcium, phosphate, or vitamin D:
   • serum calcium.
   • serum phosphate.
   • sodium.
   • potassium.
   • creatinine.
   • acid/base balance.
5. Treatment is continued until biochemical indices are normal and radiographic evidence of healing is present.
6. Consider other nutritional deficiencies (for example zinc) in an infant who is failing to thrive with evidence of significant bone disease.

References