Calcium and phosphorus supplementation of human milk for preterm infants

  • Review
  • Intervention




Preterm infants are born with low skeletal stores of calcium and phosphorus. Preterm human milk provides insufficient calcium and phosphorus to meet their estimated needs.


To determine if addition of calcium and phosphorus supplements to human milk leads to improved growth and bone metabolism without significant adverse effects in preterm infants.

Search methods

The standard search strategy of the Cochrane Neonatal Review Group (NRG) was used. This includes searches of the Oxford Database of Perinatal Trials, MEDLINE, previous reviews including cross references, abstracts, conferences and symposia proceedings, expert informants, journal handsearching mainly in the English language.

Selection criteria

All trials utilizing random or quasi-random allocation to supplementation of human milk with calcium and/or phosphorus or no supplementation in preterm infants within a hospital were eligible.

Data collection and analysis

Data were extracted using the standard methods of the Cochrane NRG, with separate evaluation of trial quality and data extraction by each author and synthesis of data using relative risk and weighted mean difference.

Main results

No studies which met selection criteria were identified. Excluded studies that were identified included minerals as one component of a multicomponent fortifier or reported only non-clinical outcomes (for example, urinary excretion of calcium). Two studies were excluded because of methodological concerns.

Authors' conclusions

There are no randomized controlled data evaluating clinical outcomes of calcium and phosphorus supplementation of human milk for preterm infants on which to base practice recommendations. Further trials should assess the clinical benefits and potential adverse effects of supplementation of human milk with minerals. This may best be done in the context of manipulation of the composition of human milk fortifiers containing multiple nutrients (carbohydrate, protein, and minerals).

Plain language summary

Calcium and phosphorus supplementation of human milk for preterm infants

Adding extra calcium and phosphorus to human milk for increasing growth in preterm infants. Preterm infants are born with low skeletal stores of calcium and phosphorus as some two-thirds of mineral content is taken up in the third trimester of pregnancy. This puts them at risk for fractures and lower-than-expected growth rates as these minerals are important for strong bones. This has led to widespread mineral supplementation of human milk and preterm formulae. An infant can drink large volumes to obtain sufficient protein and sodium as well. In excess, supplemental calcium and phosphorus may have adverse effects including a build up of calcium (including in the kidneys) and feeding intolerance. The review authors searched the medical literature for controlled studies measuring growth and bone metabolism of preterm infants within a hospital setting with supplements of calcium and phosphorus in human milk. No studies fortified human milk with just calcium and phosphorus, they added multiple nutrients including carbohydrate, protein, and minerals.