The Association of Serum 25-Hydroxyvitamin D Status in Patients with Osteoarthritis in the Primary Care Office

Background: Low serum 25-hydroxyvitamin D [25(OH)D] and osteoarthritis (OA) are commonly found in patients followed up in a primary care office. Clear evidence to support the link between 25-hydroxyvitamin D levels and OA is lacking. Aim: To describe the association of serum 25-hydroxyvitamin D status in patients with OA in the primary care office. Materials and Methods: We reviewed the records of 1,455 patients seen in our primary care office between November 2013 and October 2014. All patients were older than 18 years and had a diagnosis of OA. Demographic characteristics as well as 25(OH)D levels and comorbidities were analyzed. Results: Levels of 25(OH)D were available in 1,222 patients with OA. Fifty-one percent of the patients had a low 25(OH)D level. Patients with OA and low 25(OH)D were on an average 5 years younger than patients with OA and normal 25(OH)D (P < 0.001). African Americans (71.7%) and Hispanics (63.1%) had a higher prevalence of low 25(OH)D compared to Whites (42.9%) and other races (49.1%) (P < 0.001). There were significantly more smokers (15.4%) and patients with type 2 diabetes (27.6%) in the group of patients with osteoarthritis and low 25(OH)D (P < 0.001). A lower prevalence of hypothyroidism (18.5% versus 27.4%) and higher body mass index (BMI) were also noted in the group of interest. Conclusion: Patients with low levels of 25(OH)D and OA are younger than their counterparts with low 25(OH)D level. Future studies are needed to clarify the relationship between 25(OH)D level and OA.