en Oncology Oncology Original Article Original Article <span style="font-size:14px;"><span style="font-family:Times New Roman;"><span style="color:#0000ff;"><em><strong>Background: </strong></em></span>To examine the serum levels of vitamin D in newly diagnosed gastric cancer (GC) patients compared with normal subjects and any possible association with prognostic variables.<br> <span style="color:#0000ff;"><em><strong>Methods: </strong></em></span>One-hundred subjects (50 GC and 50 controls) were enrolled and serum vitamin D levels were assessed using ELISA. Based on two definitions, vitamin D was classified as a sufficient level (&ge;30 ng/dL) and optimal level (25-80 ng/dL). The &chi;2 and unpaired t-test was used for data analysis with a significance level of 0.05.<br> <span style="color:#0000ff;"><em><strong>Results: </strong></em></span>The mean serum levels of vitamin D in patients and controls were 26.86 (&plusmn;14.6) and 31.72 (&plusmn;13.4), respectively (P=0.09). The prevalence of vitamin D insufficiency and deficiency was higher in GC cases than controls (P=0.045 if sufficient level &ge;30 and P=0.065 if sufficient level &ge;25). According to histological grade analysis, grade 3 patients (poorly differentiated) were found with significantly lower vitamin D concentrations in serum than grade 1 and 2 subjects (22.25 vs 33.29 ng/dL, P=0.021). No significant differences were observed between the two groups in pathological tumor-node-metastasis (pTNM) stages, distant metastasis, and location of the tumor.<br> <span style="color:#0000ff;"><em><strong>Conclusion: </strong></em></span>Higher prevalence of vitamin D insufficiency and deficiency in GC patients may reflect its role in malignancy; however, further studies are needed to confirm this relationship and any possible benefits to the patients.a</span></span> Gastric cancer, vitamin D, ELISA 290 294 http://caspjim.com/browse.php?a_code=A-10-466-2&slc_lang=en&sid=1 Akbar Hedayatizadeh-Omran akbar_hedayati@yahoo.com 100319475328460023539 100319475328460023539 No Gastrointestinal cancer research center, Mazandaran University of Medical Sciences, Sari, Iran. Ghasem Janbabaei janbabai@yahoo.com 100319475328460023540 100319475328460023540 No Gastrointestinal cancer research center, Mazandaran University of Medical Sciences, Sari, Iran. Reza Alizadeh-Navaei reza_nava@yahoo.com 100319475328460023541 100319475328460023541 No Gastrointestinal cancer research center, Mazandaran University of Medical Sciences, Sari, Iran. Omolbanin Amjadi prs.amjadi0o0@gmail.com 100319475328460023542 100319475328460023542 No Gastrointestinal cancer research center, Mazandaran University of Medical Sciences, Sari, Iran. Jeyran Mahdavi Izadi jeyranmahdavi@yahoo.com 100319475328460023543 100319475328460023543 No Gastrointestinal cancer research center, Mazandaran University of Medical Sciences, Sari, Iran. Versa Omrani-Nava versa.peace@gmail.com 100319475328460023544 100319475328460023544 Yes Gastrointestinal cancer research center, Mazandaran University of Medical Sciences, Sari, Iran.