Prevalence of vitamin D inadequacy in Belfast following fragility fracture

It is well established that vitamin D levels are sub-optimal in older people and that adults with fragility fracture have low levels of serum vitamin D.

To investigate the prevalence of vitamin D inadequacy in an elderly population with fragility fractures and to compare data with previously published work from Glasgow.

Two retrospective patient audits were carried out using records from the out-patient Osteoporosis Clinic at Musgrave Park Hospital and from in-patient hip fracture admissions at the Royal Victoria Hospital.

There were data for 86 patients with fragility fracture from the Osteoporosis Clinic, 40.7% patients had vertebral fractures and 10.5% multiple fractures. Patients with hip fracture were excluded from the analysis. 69.8% of the patients were women. The mean age at the time of fracture was 65.3 years and 70.9% of patients were aged 60 years or over and 32.6% were aged 75 years or over. At the time of out-patient attendance, 73.3% were receiving supplementation with calcium and vitamin D. The mean vitamin D level was 52.3 nmol/L (21.0 ng/mL), SD = 23.4 (9.4). There were 83.7% of patients who had a vitamin D level < 80 nmol/L, 73.3% < 70 nmol/L and 55.8% < 50 nmol/L. There were no significant differences by patient age or sex. Data were also analysed according to supplementation status, in patients not taking supplements (n = 23) mean vitamin D level was 48.1 nmol/L (19.3 ng/mL), SD = 27.4 (11.0) compared with 53.8 nmol/L (21.6 ng/mL), SD = 21.8 (8.7) in the 63 patients taking supplements. Prevalence of inadequacy was higher in the patients not taking supplements 82.6% versus 67.1% at the 70 nmol/L threshold. There were data for 43 hip fracture patients, 95.3% of the patients were women. The mean age at the time of fracture was 78.3 years, 95.3% of patients were aged 60 years or over and 69.8% were aged 75 years or over. Data were not available on whether these patients were receiving supplementation. The mean vitamin D level was 36.1 nmol/L (14.5 ng/mL), SD = 24.8 (9.9). 90.7% of patients had a vitamin D level < 80 nmol/L, 88.4% < 70 nmol/L ( approximately 28 ng/mL) and 88.4% < 50 nmol/L ( approximately 20 ng/mL).

The levels of vitamin D inadequacy revealed in this audit were similar to those in an earlier audit carried out in Glasgow. Thus studies at two locations in the UK confirm the high prevalence of vitamin D inadequacy, furthermore, the prevalence of inadequacy appears to be higher in those patients with a hip fracture.