Randomised controlled trial of vitamin D supplementation on bone density and biochemical indices in preterm infants
- aDepartment of Paediatrics, Tampere University Hospital, Tampere, Finland, bDepartment of Clinical Chemistry, cUKK Institute, Tampere, Finland, dInstitute of Medical Technology, University of Tampere, eTampere School of Public Health, University of Tampere, Tampere
- Dr Maria Backström Karlebyvägen 1457 66530, Kvevlax Finland. Email: maria.backstrom{at}pp.qnet.fi
- Accepted 27 October 1998
Abstract
AIMS To test the hypothesis that a vitamin D dose of 200 IU/kg, maximum 400 IU/day, given to preterm infants will maintain normal vitamin D status and will result in as high a bone mineral density as that attained with the recommended dose of 960 IU/day.
METHODS Thirty nine infants of fewer than 33 weeks of gestational age were randomly allocated to receive vitamin D 200 IU/kg of body weight/day up to a maximum of 400 IU/day or 960 IU/day until 3 months old. Vitamin D metabolites, bone mineral content and density were determined by dual energy x-ray absorptiometry, and plasma ionised calcium, plasma alkaline phosphatase, and intact parahormone measurements were used to evaluate outcomes.
RESULTS The 25 hydroxy vitamin D concentrations tended to be higher in infants receiving 960 IU/day, but the differences did not reach significance at any age. There was no difference between the infants receiving low or high vitamin D dose in bone mineral content nor in bone mineral density at 3 and 6 months corrected age, even after taking potential risk factors into account.
CONCLUSIONS A vitamin D dose of 200 IU/kg of body weight/day up to a maximum of 400 IU/day maintains normal vitamin D status and as good a bone mineral accretion as the previously recommended higher dose of 960 IU/day. Vitamin D is a potent hormone which affects organs other than bone and should not be given in excess to preterm infants.
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The ideal vitamin dose for preterm infants is controversial
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A directly administered vitamin D dose of 200 IU/kg of body weight/day (maximum 400 IU/day) maintains normal vitamin D status and does not endanger bone mineral accretion in preterm infants supplemented with minerals
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Vitamin D administration should be precise and and based on evidence based criteria, analagous to those for other potent hormones
