Vitamin D is a hormone mainly synthesized in the skin in the presence of sunlight. Like other hormones, vitamin D plays a role in a wide range of processes in the body. Some studies have shown vitamin D has anti-inflammatory effects in the body by reducing the release of pro-inflammatory cytokines and suppressing T-cell responses. Therefore, vitamin D may be effective on reduce pain by such mechanisms. In this trial patients with brain tumor under craniotomy will receive a single high dose vitamin D compared to the control group.

A randomized, double blind, controlled trial will be conducted in intensive care unit (ICU) and neurosurgery ward, in Shohada-E-Tajrish hospital,Tehran, Iran. First, patients will be carefully checked for inclusion and exclusion criteria. Then, the eligible patients will complete the consent form for this study. 60 eligible brain tumor patients diagnosed by surgeon that are ready for craniotomy will be selected.These patients will be divided into two groups. Intervention group will be received an intramuscular (IM) single dose of vitamin D (300000 IU),while another group will not receive. Pain in patients will be checked daily by up to 3 days after surgery. Finally, the VAS pain score will be compared in both groups.

Inclusion Criteria:

• Written informed consent of patient or legal representative
• 25(OH)D level below 20ng/dL

Exclusion Criteria:

• Other trial participation, including previous participation in the pilot trial
• Pregnant or lactating women
• Hypercalcemia
• Hyperphosphatemia
• Tuberculosis
• Sarcoidosis
• History of nephrolithiasis
• History of hyperparathyroidism
• Medications that interfere with vitamin D metabolism
• Renal Insufficiency