Functional indicators of vitamin D adequacy for very low birth weight infants

Objectiveto identify the vitamin d status to optimize calcium and bone health in preterm infants.study designvery low birth weight infants had measurement of 25-hydroxyvitamin d status and markers of calcium and bone health from birth to term age. piecewise linear regression modeling was performed to identify a 25-hydroxyvitamin d threshold associated with stable parathyroid hormone concentration and bone mineralization.resultsin a cohort of 89 infants at term age, femur bmc and density increased linearly with 25-hydroxyvitamin d status until reaching a threshold of 48 ng/ml and 46 ng/ml, respectively. parathyroid hormone status decreased as vitamin d status increased until reaching a plateau at 25-hydroxyvitamin d of 42 ng/ml.conclusionpreterm infant vitamin d status was significantly associated with pth status and femur mineralization with suggestion that achieving a specific 25-hydroxyvitamin concentration is associated with optimal calcium homeostasis and femur bone mineralization.