Mc. Backstrom et al., Randomised controlled trial of vitamin D supplementation on bone density and biochemical indices in preterm infants, ARCH DIS CH, 80(3), 1999, pp. F161-F166
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 re
commended 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 metabol
ites, bone mineral content and density were determined by dual energy x-ray
absorptiometry, and plasma ionised calcium, plasma alkaline phosphatase, a
nd intact parahormone measurements were used to evaluate outcomes.
Results-The 25 hydroxy vitamin D concentrations tended to be higher in infa
nts 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 an
d 6 months corrected age, even after taking potential risk factors into acc
ount.
Conclusions-A vitamin D dose of 200 IU/kg of body weight/day up to a maximu
m of 400 IU/day maintains normal vitamin D status and as good a bone minera
l accretion as the previously recommended higher dose of 960 IU/day. Vitami
n D is a potent hormone which affects organs other than bone and should not
be given in excess to preterm infants.