Sodium intake in very low birth weight infants: is more always better?

The problem of sodium balance in low birth weight infants In this issue of Jornal de Pediatria, Tanaka et al. publish results of their detailed study to assess the influence of fortification of banked human breast milk feeding on urinary fractional excretion of sodium, specific gravity and osmolality.1 To our knowledge, no study in very low birth weight infants to date has examined strict sodium balance in this premature population first achieving postnatal growth with enteric feeding of human breast milk. The authors assume, and I think correctly, that human breast milk is the best nutritional resource for feeding premature human babies.