National Osteoporosis Society Vitamin D Guideline Summary

The National Osteoporosis Society (NOS) published its document, Vitamin D and Bone Health: A Practical Clinical Guideline for Patient Management, in 2013 as a practical clinical guideline on the management of vitamin D deficiency in adult patients with, or at risk of developing, bone disease. There has been no clear consensus in the UK on vitamin D deficiency its assessment and treatment, and clinical practice is inconsistent. This guideline is aimed at clinicians, including doctors, nurses and dieticians. It recommends the measurement of serum 25 (OH) vitamin D (25OHD) to estimate vitamin D status in the following clinical scenarios: bone diseases that may be improved with vitamin D treatment; bone diseases, prior to specific treatment where correcting vitamin D deficiency is appropriate; musculoskeletal symptoms that could be attributed to vitamin D deficiency. The guideline also states that routine vitamin D testing is unnecessary where vitamin D supplementation with an oral antiresorptive treatment is already planned and sets the following serum 25OHD thresholds: <30 nmol/l is deficient; 30-50 nmol/l may be inadequate in some people; >50 nmol/l is sufficient for almost the whole population. For treatment, oral vitamin D3 is recommended with fixed loading doses of oral vitamin D3 followed by regular maintenance therapy when rapid correction of vitamin D deficiency is required, although loading doses are not necessary where correction of deficiency is less urgent or when co-prescribing with an oral antiresorptive agent. For monitoring, serum calcium (adjusted for albumin) should be checked 1 month after completing a loading regimen, or after starting vitamin D supplementation, in case primary hyperparathyroidism has been unmasked. However, routine monitoring of serum 25OHD is generally unnecessary but may be appropriate in patients with symptomatic vitamin D deficiency or malabsorption and where poor compliance with medication is suspected. The guideline focuses on bone health as, although there are numerous putative effects of vitamin D on immunity modulation, cancer prevention and the risks of cardiovascular disease and multiple sclerosis, there remains considerable debate about the evaluation of extraskeletal factors and optimal vitamin D status in these circumstances.