Assessment of Relationship between Vitamin D Deficiency and Pain Severity in Patients with Low Back Pain: A Retrospective, Observational Study

BACKGROUND: Vitamin D is associated with musculoskeletal function in our body, and its deficiency is a common health problem all over the world. Low back pain (LBP) is an important health problem in terms of low quality of life, loss of work power, and cost of diagnosis and treatment approaches. AIMS: The purpose of this study is to investigate the relationship between pain severity and Vitamin D deficiency in patients who applied to pain polyclinic with LBP. SETTINGS AND DESIGN: This was a retrospective, observational study. SUBJECTS AND METHODS: The files of patients aged between 18 and 70 years who applied to our hospital between January and February 2018 were examined retrospectively by a specialist. Serum 25-hydroxyvitamin D (25(OH)D) level, Visual Analogue Scale (VAS), age, education level, marital status, working status, and body mass index (BMI) values recorded in patient files were included in the study. The limit value of Vitamin D was accepted as 20 ng/mL. Patients were divided into two groups according to their levels of Vitamin D. Patients with serum 25(OH)D levels below 20 ng/mL were considered as the deficiency of Vitamin D (Group 1) and patients with 20 ng/mL and over 20 ng/mL values were considered as normal in terms of Vitamin D (Group 2). STATISTICAL ANALYSIS USED: Descriptive statistical data were presented as mean, standard deviation, numbers, and percentage. There was no difference between the normally distributed group and the non-normally distributed group in terms of vitamin D levels. To compare the frequencies, the Chi-square test was used. To define the linear association between independent variables and Vitamin D level, Spearman's rho correlation coefficients were calculated. RESULTS: The level of Vitamin D was measured in 98 patients aged 18–70 years who applied to our hospital's polyclinic due to LBP during the study period. The deficiency of vitamin was detected in 84 (85.7%) of the patients, while Vitamin D was found in 14 (14.3%) as normal. Groups were similar in terms of age, gender, BMI, educational level, marital status and working status (p> 0.05); however, there was a statistically significant difference between the two groups in terms of VAS score and levels of Vitamin D (P < 0.001 and P < 0.001, respectively). While there was a negative correlation between D vitamin level and VAS score (r = −0.594, P < 0.001), there was no correlation between age, gender, BMI, education level, marital status, and working status (P > 0.05). CONCLUSIONS: The deficiency of Vitamin D is often asymptomatic, and also, it can cause bone and muscle pain. In our study, we determined that the severity of pain increased in patients with LBP as the deficiency of Vitamin D increased. For this reason, we recommend to be evaluated the level of Vitamin D in patients with LBP.