Supplements for the preterm infant

Total body iron in a newborn is approximately 75 mg/kg, with most of this within the blood volume. Therefore, the smaller the baby the lower their iron stores. Risk  for iron deficiency is compounded by losses of iron due to blood tests and low iron content in breast milk.

Iron supplements are not required for infants receiving preterm infant formula or human milk fortifier containing iron. All other infants born at less than 35 weeks gestation on full milk feeds should commence iron supplementation from four weeks of life and continue until at least six months of age or when consuming a range of iron-rich solids.

Recommended preparation for iron supplements

Ferrous Sulphate Oral liquid:

contains 150 mg / 5 mL ferrous sulphate, equivalent to 30 mg / 5 mL of elemental iron

Recommended doses for iron supplements

Note:

• Consider single daily dosing at discharge.
• As there are also risks of excessive iron supplementation, care should be taken with dosage. Excessive iron supplementation can increase infection risk, inhibit growth, disturb the absorption of other minerals, and potentially increase the risk of free oxygen radical formation and retinopathy of prematurity (ROP).

Studies have shown that giving vitamin E supplements to preterm infants can provide some benefits, but may also increase the risk of life-threatening infections, such as sepsis.

Vitamin E is not routinely used in most Level 6 neonatal units. If an infant is transferred from a  Level 6 service that has prescribed Vitamin E supplementation to a lower level of neonatal care, then supplementation can be continued up to 36 weeks corrected age.

Recommended dosage of Vitamin E

0.1 mL daily of Pretorius Professional Vitamin E. (156 International Units of alpha-tocopherol) 

For some premature infants, Vitamin D deficiency can present a clinical problem, although most are asymptomatic.

OsteVit-D, rather than Pentavite, is recommended for all but the most premature infants.

• OsteVit-D is administered to:
  • all infants born before 37 weeks
  • infants weighing less than 2 kg at birth
  • at-risk babies (for example, dark skinned)
  • babies whose mother is known to be vitamin D deficient.

Commence dose on day five of enteral feeds

Recommended dosage of Vitamin D

• 0.1 mL daily (equivalent to 500 international units of cholecalciferol)
• Continue to administer throughout the first 12 months of life.

Hyponatremia is a serum sodium concentration less than 135 mEq/L.

• Significant hyponatremia may cause seizures or coma.
• Low sodium in the first two weeks of life is usually due to fluid overload.
• Very low birth weight infants can develop hyponatraemia secondary to renal losses.
• Low total body sodium can be an important cause of poor weight gain.

Recommended dosage of sodium

• Sodium is supplemented orally as 20 per cent NaCl (3.4 mmol/mL) solution, mixed with a feed.
• The dose is 3 mmol/kg/day and may need to be increased to 6 mmol/kg/day, given in three divided doses.
• Sodium levels should be monitored once a week while on supplements.
• Supplementation is not needed once growth is satisfactory and the serum Na level is maintained within normal range off the supplement.

Metabolic bone disease of prematurity

Osteopenia is a significant problem for very premature babies, and there is some suggestion that hypophosphataemia prolongs the need for ventilator support. Some very premature babies have very ‘thin’ bones on their x-rays.

Recommended supplements for osteopenia

Supplementation of calcium, phosphate and Vitamin D may be required despite full volume feeds and “bone bloods” should be monitored.

This is covered in the topic osteopenia of prematurity

• King Edward Memorial Hospital & Princess Margaret Hospital, Neonatology Clinical Care Unit 2016, Neonatal medication protocol. Ferrous sulphate. Accessed 2016
• NSW Health, Sydney Local Health District 2014, Guideline: Women and babies: enteral nutrition for the preterm infant, NSW Government, Sydney.
• Vitamin E supplementation for the prevention of morbidity and mortality in preterm infants, World Health Organization