Background In the last few years it has been highlighted that vitamin D deficiency is common in the general population however, the extent of the problem in different HIV+ cohorts is less clear.

Aims In a cohort of HIV+ patients in North West London we looked at the vitamin D levels to see what the prevalence of deficiency was and see if there were any correlates with ethnicity or season.

Methods All HIV+ patients at this centre and who had a recorded vitamin D test result in the last 2 years were identified. The first result while not on treatment was recorded. The patients' electronic case records were examined to identify any correlates with the results. Vitamin D was classified as deficient, insufficient or adequate with total 25-hydroxy vitamin D blood levels of <12.5, 12.5–50 and >50 nmols/l respectively.

Results 143 patients had a least one vitamin D level measured. Of these 7 (5%) had vitamin D deficiency, 83 (58%) insufficient levels and 53 (37%) had adequate levels. Comparing patients who had levels tested in the winter months with those tested in the summer, they were more likely to show deficient or insufficient levels than adequate levels (44/90 (49%) vs 6/53 (11%) p<0.0001). All patients who showed gross deficiency were black or Asian but there wasn't a correlation between ethnicity and insufficient/deficient levels. Three (42%) of the patients with deficient levels had a raised serum alkaline phosphotase and/or a low serum phosphate.

Conclusions High rates of vitamin D deficiency and insufficiency were found in this cohort, only part of which is explained by doing the test in the winter months. Some evidence of metabolic effects of deficiency on bone was found