The efficacy of vitamin D supplementation in infants on bone mineral content: A double blind randomized controlled trial.

Vitamin D deficiency is a public health issue in developed countries. Many countries recommend supplementing infants with 400 IU/day of vitamin D. These recommendations have been introduced based on the evidence that supplementation reduces the risk of rickets, which occurs generally among those with moderate to severe vitamin D deficiency. There is debate whether a similar policy should be introduced in Australia where rickets only occurs in high risk groups which can be easily identified. While vitamin D has potential benefits for bone health beyond the prevention of rickets by improving bone acquisition, the current evidence in infants is sparse, inconsistent and cannot even rule out a detrimental effect on bone. An expansion from supplementation of at-risk to supplementing all infants should only occur if there are health benefits beyond rickets. However, practice is starting to run ahead of the evidence, and infants are now increasingly being supplemented in the absence of this evidence. High quality and well-powered randomised controlled trial (RCT) evidence is required to show that supplementation of mildly deficient infants is beneficial and does not cause harm. Aim – To determine whether vitamin D supplementation of 400 IU/day of cholecalciferol from birth to age 2 yrs improves bone health outcomes Hypothesis – Compared to placebo, vitamin D supplementation from birth to age 2 years improves whole body bone mineral content at age 2 and 4 years. Significance – Irrespective of its outcome, this study is critical to our ability to make evidence-based decisions around vitamin D supplementation programs in infancy. If our hypothesis is supported, it has the potential to reduce childhood fracture risk by ~50% with a 5% increase in bone mineral density and to delay the onset of osteoporosis in later life by as much as 13 years with a 10% increase in peak bone mass.