NOS guidance on vitamin D and bone health – clarity at last?

tance of vitamin D deficiency as a risk factor for bone disease and the potential benefit of vitamin D supplementation in terms of reducing fracture risk are areas that have been under much scrutiny in recent times. Increasingly, it is realised that vitamin D is no longer just a nutritional supplement but is an important sterol hormone with receptors found across a wide variety of cell types.1 As such, its importance in disease is increasingly being established in cancer, diabetes, vascular disease and neurological disorders.2 Despite these emerging areas of interest, it is in relation to bone health that clinicians are most in need of clear, practical and evidence-based guidelines to determine which patients require assessment, biochemical testing and treatment. To date there has been a lack of clarity and consensus with regards to the clinical and biochemical criteria necessary for the diagnosis of vitamin D deficiency. In the UK, this lack of clarity combined with historical problems in sourcing appropriate preparations of vitamin D and an absence of national guidance have all contributed to the confusion. There has also been concern in many areas about a significant rise in laboratory requests for the measurement of 25-hydroxy-vitamin D (25OHD), leading to escalating laboratory costs and uncertainty in the clinical interpretation of results.3 Against this background it is most welcome that a practical guideline discussing bone health and vitamin D has become available on behalf of the National Osteoporosis Society (NOS).4