Background: Multiple sclerosis (MS) is an autoimmune disease accompanied by release of inflammatory cytokines, which induce osteoclastogenesis affecting bone metabolism, causing osteoporosis (OP). However, OP in MS patients is multifactorial. The purpose of this study was to examine the prevalence of aberrant bone mineral density (BMD) and its correlation with demographic and clinical variables in MS patients, investigating the role of vitamin D (VD) levels and determining predictors of aberrant BMD.

Methods: This cross-sectional study enrolled 124 patients. Disability and severity scores, along with MRI brain results, were documented. Levels of 25 (OH) cholecalciferol, parathyroid hormone, and serum calcium were recorded. Using dual-energy X-ray absorptiometry, BMD was determined.

Results: 120 patients were identified with VD deficiency. 56.5% exhibited reduced BMD in the spine, and 54.8% showed decreased BMD in the femur. Negative correlation was detected between VD and frequency of relapses over the preceding two years. Additionally, femoral Z-scores were negatively correlated with age, disease duration, total serum calcium levels, disability and severity scores. Significant relationships were found between the Z-scores of the forearm, femur, and spine and the overall lesion load. Multivariate logistic regression revealed an independent correlation between the incidence of relapses in the past two years and low BMD

Conclusion: High prevalence of low BMD is seen in MS patients. More than half exhibiting reduced BMD. VD deficiency was frequently observed and correlated with an increased number of relapses. Patients are more likely to have low BMD if they had more relapses in the previous two years.