4.3 Details of Measurements INFANT: NUTRITIONAL AND HORMONAL STATUS AND BONE METABOLISM 4.3.1 Sample procurement: Blood and urine samples will be collected in infants at all visits. All samples will be taken between 8 and 10 am to control for diurnal variation permitting 3 to 4 infants to be seen in our Unit daily. Heparinized blood (~1 ml in infants via finger poke - 400 ul for safety, 600 ul for other measurements) and non-pharmacological approaches used to provide for pain control including swaddling and 1 ml 33% sucrose solution given sub lingual 2 minutes prior to collection (46).