SLR - April 2013 - Patricia Kim
Reference: Boszczyk AM, Zakrzewski P, Pomianowski S. Vitamin D Concentration in Patients with Normal and Impaired Bone Union. Pol Orthop Traumatol. 2013 Jan 2;78:1-3.
Scientific Literature Review
Reviewed by: Patricia Kim, DPM
Residency Program: Beth Israel Deaconess Medical Center, Boston, MA
Podiatric Relevance:
There is increasing evidence regarding the positive benefits of Vitamin D and skeletal health and function. Vitamin D is obtained through sunlight exposure, dietary sources, and oral supplements. There is an integral relationship between Vitamin D, parathyroid hormone (PTH), calcium, and phosphate. Vitamin D’s function has long been known to maintain calcium serum homeostasis which correlates to bone density. There have been multiple studies demonstrating a decrease in the risk of fractures as well as a reduction in all fractures in patients with both Vitamin D and calcium supplementation. Difficulty arises for the practitioner in assessing a patient’s healing potential due to the paucity of research on Vitamin D levels alone. Most of the evidence that has been published relates both Vitamin D and calcium supplementation in conjunction with each other. A Cochrane review demonstrated that Vitamin D supplementation alone did not decrease fractures, but that when taken with calcium, was effective in reducing the risk of fractures. Due to the possible musculoskeletal benefits for surgical patients, it is important for podiatric surgeons to play a role in diagnosis and treatment of vitamin D deficiency.
Methods:
In this retrospective study, 35 patients with delayed bone union or non-union were enrolled (25 cases of atrophic pseudoarthrosis and 10 cases of hypertrophic pseudoarthrosis). Inclusion criteria for this group were: closed fracture of a long bone diaphysis with surgical implantation of intramedullary rods or plates. Exclusion critera were: open fracture, inflammatory complications, comorbid disease, or taking drugs with known adverse effects on bone healing. This included drugs in the treatment of diabetes, malnutrition, anemia, hypothyroidism, long term steroid therapy, and anti-convulsants. Each patient in the impaired bone union group (N=35) was assigned to a control patient (N=35). Patients were assigned to each other with respect to age within 10 years of each other, sex, and time of fracture. The delayed bone union group and control group were similar with respect to age (mean=40.32 and mean=40.11, respectively), sex (25/31), and smoking prevalence (40 percent and 37 percent). Five-milliliter samples of venous blood were collected from each patient; frozen serum was sent for LIAISON test which measures concentration of total 25(OH)D. Vitamin D deficiency was defined as concentrations below 30 mg/mL. Observation pairs were compared using Wilcoxon signed-rank test, and the impact of vitamin D concentration on success of fracture healing was assessed using McNemar non-parametric test.
Results:
Mean vitamin D concentration was 20.86 mg/mL in the impaired union group and 19.32 mg/mL in the normal bone union group. No difference was reported between groups for observation pairs (p>0.1). Vitamin D deficiency was present in 86 percent of patients in both groups. There was no relationship for vitamin D concentration on the success of bone union.
Conclusion:
This study demonstrated no correlation between vitamin D levels in patients with impaired bone healing and those with normal healing. This suggests that vitamin D alone does not have a significant impact on fracture healing, although it still plays an important role in metabolic and endocrine functions. Further research is warranted to determine whether vitamin D is efficacious in skeletal healing and if so, is in conjunction with other supplementation such as calcium versus alone.