The goal of this randomized clinical trial is to compare the effect of higher (10 mg per day) versus standard (1 mg per day) doses of zinc supplementation The main questions it aims to answer are: * Growth velocities and delta z-scores during the date of start intervention until the end of the time interval (at least 2 weeks of intervention on date of 44 weeks of postmenstrual age or discharge whichever came first) in very preterm infants with a birthweight less than1800 grams. * Growth and neurodevelopment at 24 months postnatal age