Because of the lack of well designed studies on vitamin D and health,1 the British Paediatric and Adolescent Bone Group has produced a position statement based on current expert opinion. This statement is supported by the British Society of Paediatric Radiology and child protection and nutrition committees of the Royal College of Paediatrics and Child Health.

There is currently considerable clinical and research interest in vitamin D deficiency. Definitions of a sufficient vitamin D concentration vary across clinical guidelines. This causes confusion and may influence clinical decision making in children and adolescents.
The British Paediatric and Adolescent Bone Group’s current opinion is that the definition of vitamin D deficiency should relate only to vitamin D’s effect on the skeleton. Deficiency should be a plasma concentration of 25 hydroxyvitamin D of less than 25 nmol/L (10 ng/mL), with insufficiency being 25-50 nmol/L and sufficiency a concentration greater than 50 nmol/L. We generally use these thresholds in practice, although we recognise that the evidence base in children and adolescents is limited.

In infants with unexplained fractures, unless conventional radiography and biochemistry (abnormal blood concentrations of calcium, phosphate, alkaline phosphatase, or parathyroid hormone) provide evidence of rickets, 25 hydroxyvitamin D is not implicated.

It is important that people at risk of vitamin D deficiency take vitamin D supplements, as recommended by the chief medical officers for the UK.2 These include all pregnant or breastfeeding women and all infants and children from the age of 6 months to 5 years. We also recommend that exclusively breastfed infants receive vitamin D supplements from soon after birth.

BMJ 2012;345:e8182