Clinical studies evaluating the effects of vitamin D alone or in combination with calcium on physical function, falls and fractures have been inconsistent. Vitamin D has, however, been the focus of much orthopaedic, trauma and endocrine research. Playing a central role in muscle and bone metabolism, some studies on Vitamin D therapies offer the tantalising suggestion of a reduction in falls and fractures simply with vitamin D supplementation. We review the background and evidence behind vitamin D.

Slipped capital femoral epiphysis (SCFE) is uncommon in India and we routinely look for associated metabolic or endocrine abnormalities. In this study we investigated a possible association between vitamin D deficiency and SCFE. All children presenting with SCFE during the study period had their 25-hydroxyvitamin D levels measured as part of an overall metabolic, renal and endocrine status evaluation, which included measurement of body mass index (BMI). Vitamin D status was compared with age-, gender- and habitat-matched controls with acute trauma or sepsis presenting to our emergency department.

A total of 15 children (12 boys and three girls) with a mean age of 13 years (sd 1.81; 10 to 16) presented for treatment for SCFE during a two-year period beginning in January 2010. Renal and thyroid function was within the normal range in all cases. The mean BMI was 24.9 kg/m² (17.0 to 33.8), which was significantly higher than that of the controls (p = 0.006). There was a statistically significant difference between the mean values of 25-hydroxyvitamin D in the children with SCFE and the controls (11.78 ng/ml (sd 5.4) versus 27.06 ng/ml (sd 5.53), respectively; p < 0.001). We concluded that, along with high BMI, there is a significant association of vitamin D deficiency and SCFE in India.

Cite this article: Bone Joint J 2013;95-B:851–4.

We measured the plasma 25-hydroxyvitamin D₃ (25(OH)D₃) levels in 62 consecutive Caucasian patients undergoing total hip replacement for osteoarthritis. The patients were divided into two groups based on whether they were vitamin D sufficient or deficient. The groups were matched for age, gender and the American Society of Anaesthesiologists (ASA) grade. The prevalence of vitamin D deficiency in our patients was comparable with recent population-based studies performed in the United Kingdom. Patients with vitamin D deficiency had lower pre-operative Harris hip scores (Mann-Whitney test, p = 0.018) and were significantly less likely to attain an excellent outcome from total hip replacement (chi-squared test, p = 0.038). Vitamin D levels were found to positively correlate with both pre- and post-operative Harris hip scores.

These results warrant further study of vitamin D deficiency in patients undergoing joint replacement as it is a risk factor for a suboptimal outcome which is relatively simple and cheap to correct.