Background: Vitamin D deficiency is widely prevalent in India. The association between vitamin D status and multiple sclerosis (MS) has not been previously studied in Indians.
Objective: The objective of this paper is to determine whether vitamin D status is associated with MS in India.
Methods: In this study 110 MS patients and 108 matched controls were included. Serum 25-hydroxyvitamin D (25(OH)D) was measured in 63 patients in relapse, 77 patients in remission and all controls. Quantity of sun exposure in childhood and body mass index (BMI) were calculated. Patients and controls were genotyped for HLA-DRB1*1501.
Results: Patients had significantly lower 25(OH)D levels than matched controls (p = 0.003), and patients in relapse had a significantly lower vitamin D level as compared to those in remission (p = 0.001). Vitamin D deficiency (< 50 nmol/l) was seen in a higher proportion of cases (71.8%) than controls (53.7%) (p = 0.01). Higher quartiles of vitamin D (> 58 nmol/l) showed an inverse relationship with MS (OR = 0.28, CI = 0.11-0.68, p= 0.005). This effect persisted after adjusting for sun exposure.
Conclusion: The results of our study indicated that serum 25(OH)D shows an inverse relationship with MS in the Indian population. Reverse causality cannot be excluded.
Keywords: 25-hydroxyvitamin D; Indian population; Multiple sclerosis; sun exposure.