 Experimental design: We will establish two groups of premature newborn children 34 weeks n40. The mothers of one of the groups of premature newborn children will receive an oral supplementation by means of capsules with high dose of DHA 900 mgday during the lactation minimum period of 3 months. In addition, all the groups will be underwent to a nutritional surveillance a follow-up of 48 hours and a questionnaire of frequency of consumption and will be given nutritionally-balanced diets, insisting especially in the suitable consumption of fish 4 portionsweek. Blood samples will be obtained in all the groups at the birth moment, at the week 40 of gestational age corrected in the groups of premature babies and at the end of the lactation in all the groups minimum 3 months.We will obtain samples of mother s milk colostrum, transition and mature milk. In these samples we will study bone turnover biomarkers, pro - and anti-inflammatory citoquines and markers of aggression oxidative damage. In addition, we will perform psychomotor and visual development tests in the newborn children. 