Preterm infants and neonates are more vulnerable to times of nutrition deficits than at any other time in the life cycle. The risk of malnutrition is related to reduced nutrient stores at birth, immature nutrient absorption and use, organ immaturity, delayed advancement of parenteral and enteral feeds due to cautious advancement, and dependence on health care providers to accurately identify and effectively provide needed nutrients during a period of rapid growth and development. Complications of prematurity such as necrotizing enterocolitis and chronic lung disease can contribute to the development of malnutrition.