Vitamin D testing: three important issues

In Liverpool we are auditing vitamin D testing and prescribing in primary care, following guidelines issued to GPs in early 2012 to encourage evidenced based testing and prescribing.1 Our data indicates that some GPs are testing in an increasingly non-targeted way. GPs in Liverpool ordered over £100 000 worth of vitamin D tests in 2012, over 10 times the amount spent in 2007. Though more people were identified as deficient, the proportion of deficient results identified decreased significantly. We feel guidance from NICE is needed for detection and treatment of vitamin D deficiency in primary care.

We also feel it is high time for universal vitamin D supplementation of pregnant and postnatal women and young children as recommended by Chief Medical Officers.2 With our increasingly diverse population in the UK we are very aware that currently some groups are missing out on prevention, and Healthy Start vitamin uptake is very low. In Liverpool we are rolling out universal supplementation out this spring. This should lead to a decrease in vitamin D deficiency, decrease in rickets and decrease in need for testing and high dose prescribing.

Thirdly and very importantly the authors wonder why the use of licensed preparations is so low in primary care. This is because there are no high-dose licensed preparations available for us to prescribe. I have been working with vitamin D deficient patients for the past 10 years. My experience, as well as that of GP colleagues up and down the country, is that compliance is a big problem with low dose preparations particularly in certain population groups at risk of deficiency. Liverpool has a substantial Somali population with deficiency identified in around 80% of individuals.3 Our experience is that to ensure compliance with treatment in our Somali population we need to give a high loading dose of vitamin D over a short period of time. There is also no high-dose licensed liquid preparation for children. I note the authors appear to have had some connections with various pharmaceutical companies involved in vitamin D manufacture. It would be excellent to see some high dose preparations licensed for use in the UK.

• © British Journal of General Practice 2014