During the last few decades, neonatal survival rates for preterm infants have markedly been improved. The American Academy of Pediatrics recommended that preterm neonates should receive sufficient nutrients to enable them to grow at a rate similar to that of fetuses of the same gestational age. Although human milk is the recommended nutritional source for newborn infants for at least the first six months of postnatal life, unfortified human breast milk may not meet the recommended nutritional needs of growing preterm infants. Human milk must therefore be supplemented (fortified) with the nutrients in short supply. The fortification of human milk can be implemented in two different forms: standard and individualized. The new concepts and recommendations for optimization of human milk fortification is the "individualized fortification". Actually, two methods have been proposed for individualization: the "targeted/tailored fortification" and the "adjustable fortification". In summary, the use of fortified human milk produces adequate growth in premature infants and satisfies the specific nutritional requirements of these infants. The use of individualized fortification is recommended.