Clinical update

Updated National Osteoporosis Society guideline on vitamin D

A guideline on which patients to test and who to treat for vitamin D deficiency

A guideline on which patients to test and who to treat for vitamin D deficiency

People treated with antiresorptive agents such as denosumab may need vitamin D. Picture: SPL

Essential facts

Vitamin D helps regulate levels of the body’s calcium and phosphate, nutrients that are essential for healthy bones, teeth and muscles.

There is also a potential role for vitamin D in the prevention of non-skeletal disorders, such as autoimmune disease, cancer, mental health problems and cardiovascular disease.

The body creates vitamin D during exposure of the skin to direct sunlight. From late March to the end of September, therefore, most people should produce enough vitamin D.

However, from October to early March, people do not get enough vitamin D from sunlight.  

A lack of vitamin D can lead to bone pain caused by osteomalacia in adults.

Vitamin D deficiency is common in the UK, mainly in people:

  • Aged 65 years and over.
  • Who cover their skin for cultural reasons.
  • Who have darker skin, for example, those of African, African-Caribbean and south Asian origin.

What’s new?

The National Osteoporosis Society has published an updated guideline, Vitamin D and Bone Health: A Practical Clinical Guideline for Patient Management.

This aims to provide healthcare professionals with clarity about which patients to test for vitamin D deficiency and who to treat, with new information on toxicity levels.

People to test for vitamin D deficiency include:

  • Those with bone disease, such as confirmed osteomalacia or osteoporosis, that could be improved with vitamin D treatment.
  • Those with musculoskeletal symptoms that could be attributed to vitamin D deficiency.
  • Asymptomatic individuals at high risk of vitamin D deficiency.
  • Asymptomatic healthy individuals.

The blood test to estimate vitamin D status measures levels of 25-hydroxy vitamin D (25(OH)D). Patients with plasma 25(OH)D <25nmol/L are deficient and require treatment.


If healthcare professionals observe symptoms of vitamin D deficiency, they should act quickly. They should also act quickly if patients are about to start treatment with potent antiresorptive agents, such as zoledronate, denosumab or teriparatide.

Patients should take about 300,000 IU vitamin D3 or D2 orally in divided doses over 6-10 weeks.

Maintenance vitamin D should be started four weeks after loading doses.

If correction of vitamin D deficiency is less urgent, and when co-prescribing vitamin D supplements with an oral antiresorptive agent, maintenance therapy may be started without the use of loading doses: 800-2,000 IU vitamin D3 daily or intermittently at higher equivalent dose.

Monitoring and toxicity

Healthcare professionals should be aware that vitamin D treatment, particularly when combined with calcium supplementation, can reveal previously undiagnosed primary hyperparathyroidism.

The dosing regimen is unlikely to result in toxicity, but serum adjusted calcium should be measured one month after treating with loading doses of vitamin D.

Expert comment

Debbie_JanawayDebbie Janaway is the osteoporosis and falls nurse consultant at East Kent Hospitals University NHS Foundation Trust. She is a nurse member of the National Osteoporosis Society Clinical and Scientific Committee and represents the RCN on the Fracture Liaison Service Advisory Board

‘Vitamin D deficiency causes osteomalacia in adults and rickets in children, and can lead to bone, joint and muscle pain and muscle weakness.

‘In older people, the high prevalence of deficiency and insufficiency causes falls and fragility fractures.

‘Correction of vitamin D deficiency is essential in osteomalacia and beneficial in osteoporosis. It is also required for some people receiving treatments for osteoporosis.

‘This guideline will enable healthcare professionals to know when, and importantly, if to test.

‘It provides details about measuring plasma levels to clarify whether someone is deficient in vitamin D.

‘Reassurance about toxicity levels will allow healthcare professionals to be confident when making treatment decisions. Clarity about the correct individuals to target will enable healthcare professionals to reassure patients who are at low risk of deficiency and do not need testing or treating.

‘Nurses will find the pull-out quick guide provides simple details about who is at risk, how and when to test, interpreting results, treatment recommendations, dosing of vitamin D supplements, lifestyle recommendations and follow up.’


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