Serum and salivary levels of vitamin D in oral lichen planus patients

Introduction: Vitamin D has anti-inflammatory and immunomodulatory function. The role of vitamin D deficiency has been established in the development of many types of cancers and autoimmune diseases. Oral lichen planus (OLP) is a common chronic autoimmune in oral cavity. This study aimed to evaluate the serum and salivary levels of total vitamin 25 (OH) D3 in patients with the OLP and to assess the relationship between vitamin levels and salivary flow rate. Materials and Methods: The blood samples, unstimulated and stimulated saliva were collected from 64 patients with the OLP and 45 healthy subjects. The 25(OH) D3 levels measured by ELISA technique. The salivary flow rate was also measured in milliliters per minute. Results: The level of vitamin D3 in unstimulated and stimulated saliva of the OLP patients significantly decreased compared to the control group (p<0.001, p = 0.01 respectively). There was no significant relationship between the serum level of vitamin D3 in the OLP and control groups (p = 0.11). No significant relationship was found between serum and salivary vitamin D levels with salivary flow rate. No significant correlation was found between salivary and serum levels of vitamin D, but the severity and pain score were negatively correlated with vitamin D levels. Conclusion: Lower levels of salivary 25 (OH) D3 in the OLP patients than the healthy subjects can be an effective factor in the development of this disease. Conspicuously, saliva seems to be a more accurate tool for measuring vitamin D than serum.