Vitamin D testing guidance to prompt ‘sea change’ for GPs
GPs should test vitamin D levels in patients who display symptoms of deficiency and those with underlying bone disease who may benefit from having their levels corrected, recommends new guidance that experts have called a ‘sea change’ for primary care.
The new guidance from the National Osteoporosis Society – the UK’s first on identifying and treating vitamin D deficiency – sets out recommended groups for vitamin D testing for the first time and also specifies the levels that require treatment.
GP experts say the guidance provides ‘much needed clarity’ and will help to ‘rationalise’ testing for vitamin D levels in general practice, which has previously been restricted altogether in some regions, while being widely available in others.
The Chief Medical Officer wrote to all GPs earlier last year to urge them to prescribe vitamin D supplements in all patients at-risk of being deficient in the mineral. But Pulse revealed CCGs advised patients to spend more time in the sun and buy supplements over the counter, in order to mitigate the ‘strong impact’ Government advice on prescribing vitamin D would have had on budgets.
The guidance rules out any need for testing in people who are not considered at risk of vitamin D deficiency. It also says testing is not necessary for patients who are known to be at risk of vitamin D deficiency, such as elderly people, pregnant women and people with darker skin pigmentation, who should be advised to supplement their vitamin D levels without being tested first.
Dr Neil Gittoes, a consultant endocrinologist at Queen Elizabeth Hospital in Birmingham and co-author of the guidance, told Pulse: ‘A key idea behind the guideline is that in some parts of the country virtually everybody who walks through the door is getting vitamin D tests done, but in others patients who clearly have features compatible with vitamin D deficiency, or who have bone conditions where it would be helpful to work out whether they are deficient or not, are not receiving them.
‘I would hope [the guidance] won’t increase the total amount of testing performed but will rationalise the approach to who you test. That is one of the main directives of the guideline to help GPs and non-specialists in the area.’
According to the new advice, measuring serum 25 hydroxyvitamin (25OHD) is the best way of assessing patients’ vitamin D status; below 30 nmol/L indicates deficiency, while 30–50 nmol/L is inadequate in some groups and above 50 nmol/L is usually sufficient.
Oral vitamin D3 is the treatment of choice and patients needing rapid correction of vitamin D deficiency should be given fixed loading dose followed by maintenance therapy (see box).
Dr Michael Burke, GPSI in musculoskeletal medicine in Wirral, said: ‘This guidance is very welcome – it provides clarity on which patients to assess for vitamin D deficiency and also on appropriate treatment regimens.’
Dr Louise Warburton, GPSI in musculoskeletal medicine in Shrewsbury, Shropshire, said the guidance could lead to a ‘sea change in how we test for vitamin D deficiency and manage patients with musculoskeletal symptoms in primary care’.
She explained: ‘There is potentially an awful lot of people with chronic musculoskeletal pain who may benefit. Certainly GPs will find it useful to be able to say to people with unexplained pain, “we have found something treatable, we can do something about that aspect of it”.’
‘In my area, GPs haven’t been allowed to test for vitamin D deficiency because the perception was it’s an expensive test and there was no definite proof that it made any difference if you treated people,’ Dr Warburton added.
‘This guidance does give it more weight for a GP to be able to test – and if CCGs now to wish to commission a vitamin D testing service, they’ve got a bit more evidence now that it’s important.’
In addition, the NOS guidance endorses Department of Health advice issued last year to offer vitamin D supplementation in high-risk groups – making it clear these patients do not need to be tested first.
Dr Gittoes commented: ‘If you take the Chief Medical Officer’s perspective, then the approach [in these groups] can mean directing patients to chemists to buy over the counter preparations with relatively low doses.’
These patients can be advised to take vitamin D and calcium in combination, whereas calcium combination treatments should be avoided for people requiring rapid correction of vitamin D with high-strength vitamin D doses, because of the cardiovascular risk from the resulting high calcium doses.
Dr Gittoes noted that two licensed vitamin D only preparations have recently become available, ‘so it’s a little easier for doctors to prescribe vitamin D only’.
Test vitamin D levels (by measuring serum 25OHD levels) in:
· Patients with bone diseases that may be improved with vitamin D treatment
· Patients with bone diseases, prior to specific treatment where correcting vitamin D deficiency is appropriate
· Patients with musculoskeletal symptoms that could be attributed to vitamin D deficiency.
Where rapid correction of vitamin D required, such as in patients with symptomatic disease or about to start treatment with a potent antiresorptive agent (zoledronate or denosumab), give fixed loading doses followed by regular maintenance therapy:
· Loading regimen of approximately 300,000 IU vitamin D, given either as separate weekly or daily doses over 6–10 weeks
· Maintenance therapy of equivalent to 800–2,000 IU (occasionally up to 4,000 IU) vitamin D daily
Where correction of vitamin D deficiency less urgent or co-prescribing with oral antiresorptive, can start maintenance therapy without loading doses
Follow DH recommendation to advise 10 μg/400 IU vitamin D daily supplements in:
· All pregnant and breastfeeding women, especially teenagers and young women
· All people aged 65 years and over
· People who are not exposed to much sun, for example those who cover their skin for cultural reasons, who are housebound or confined indoors for long periods
· People from ethnic minorities who have darker skin. Clinical deficiency most reported among children of African-Caribbean and South Asian origin.