en Internal Internal Original Article Original Article <p style="margin: 0cm 0cm 0pt 161.6pt; text-indent: 0cm;"><font face="Times New Roman"><b><i><span style="color: blue; font-size: 10pt;">Background: </span></i></b><span style="font-size: 10pt;"><font color="#000000">Benign paroxysmal positional vertigo (BPPV) is a condition with recurrent attacks in a significant proportion of patients. The present case- control study was conducted to assess the influence of serum vitamin D normalization on recurrent attacks of</font><span style="color: rgb(153, 51, 0);"> </span><font color="#000000">vitamin D deficient patients.</font></span></font></p> <p style="margin: 0cm 0cm 0pt 161.6pt; text-indent: 0cm;"><font face="Times New Roman"><b><i><span style="color: blue; font-size: 10pt;">Methods:</span></i></b><span style="font-size: 10pt;"><font color="#000000"> Diagnosis of BPPV was made based on history and clinical examination and exclusion of other conditions. Serum 25-hydroxy vitamin D (25-OHD) was measured using ELISA method and a levels of < 20 ng/ml was considered a deficiency of vitamin D. Inclusion criteria were as follows: history of recurrent attacks and serum 25-OHD<20.ng/ml. While the patients with history of trauma, surgery and chronic systemic diseases were excluded. The patients were classified into two groups: treatment and control, intermittently. Both groups received Epley rehabilitation therapy one session per week for 4 weeks but the treatment group received an additional supplement of 50.000 IU of vitamin D (cholecalciferol) weekly for two months to achieve serum 25-OHD &ge; 30 ng/ml and the study patients were followed-up for 6 months.</font></span></font></p> <p style="margin: 0cm 0cm 0pt 161.6pt; text-indent: 0cm;"><font face="Times New Roman"><b><i><span style="color: blue; font-size: 10pt;">Results:</span></i></b><span style="font-size: 10pt;"><font color="#000000"> Twenty-seven patients were allocated to each group. At baseline, serum 25-OHD was similar (10.7&plusmn;2.3 vs 11.41&plusmn;1.9, P=0.23). At month 2, serum 25-OHD in the treatment group increased significantly to &ge; 30 ng/ ml, whereas serum 25-OHD in the control group remained unchanged (34.2&plusmn;3.3 vs 10.6 10.6&plusmn;2.2 ng/ml, P=0.001). During the follow-up period, attacks of BPPV in the treatment group decreased significantly compared with the control group (14.8% vs 96.3% OR= 0.18, P=0.001). </font></span></font></p> <p style="margin: 0cm 0cm 0pt 161.6pt; text-indent: 0cm;"><font face="Times New Roman"><b><i><span style="color: blue; font-size: 10pt;">Conclusion: </span></i></b><span style="font-size: 10pt;"><font color="#000000">The findings of this study indicate that the normalization of serum vitamin D significantly reduces BPPV recurrences.</font></span></font></p> BPPV, 25-hydroxy vitamin D, Epley Therapy, Recurrent vertigo 173 177 http://caspjim.com/browse.php?a_code=A-10-263-3&slc_lang=en&sid=1 Mahboobeh Sheikhzadeh m.sheikhzadeh2@yahoo.com 10031947532846005982 10031947532846005982 No Department of Audiology, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. Yones Lotfi yones1333@gmail.com 10031947532846005983 10031947532846005983 Yes Department of Audiology, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. Abdollah Mousavi amoossavi@gmail.com 10031947532846005984 10031947532846005984 No Department of Audiology, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. Behzad Heidari B.heidari@yahoo.com 10031947532846005985 10031947532846005985 No Mobility Impairment Research Center, Babol University of Medical Sciences, Babol, Iran. Enayatollah Bakhshi bakhshi@razi.tums.ac.ir 10031947532846005986 10031947532846005986 No . Department of statistics, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.