Prevalence of vitamin D deficiency in patients with foot and ankle injuries.

BACKGROUND: Vitamin D deficiency has been identified as one of the most common causes of fragility fractures and poor fracture healing. Although rates of vitamin D deficiency have been delineated in various orthopaedic populations, little is known about the prevalence of vitamin D deficiency in patients with foot and ankle disorders. The goal of this study was to identify the prevalence of vitamin D deficiency in patients with a low energy fracture of the foot or ankle.

METHODS: Over a 6-month period, a serum 25-OH vitamin D level was obtained from consecutive patients with a low energy ankle fracture, fifth metatarsal base fracture, or stress fracture of the foot or ankle. For comparative purposes, vitamin D levels in patients with an ankle sprain and no fracture were also examined.

RESULTS: The study cohort included 75 patients, of which 21 had an ankle fracture, 23 had a fifth metatarsal base fracture, and 31 had a stress fracture. The mean age was 52 (range, 16-80) years. Thirty-five of the fracture patients (47%) had an insufficient vitamin D level (below the recommended level of 30 ng/mL), and 10 of the patients (13%) had a level that was deficient (< 20 ng/mL). Vitamin D levels were significantly lower in those with a fracture than in those with an ankle sprain (P = .02). In the fracture cohort, the factors significantly associated with vitamin D insufficiency in the multivariate analysis were smoking (P = .03), obesity (P = .003), and other medical risk factors for vitamin D deficiency (P = .03).

CONCLUSION: Hypovitaminosis D was common among patients with a foot or ankle injury seen at our institution. Patients with a low energy fracture of the foot or ankle were at particular risk for low vitamin D, especially if they smoked, were obese, or had other medical risk factors. Given that supplementation with vitamin D (± calcium) has been shown to reduce the risk of fragility fractures and improve fracture healing, monitoring of 25-OH vitamin D and supplementation should be considered in patients with fractures.

LEVEL OF EVIDENCE: Level III, prospective case control.