One of the major side effects of surgery to remove the thyroid gland is transient (lasting for a short time) low calcium levels in the blood, or "hypocalcemia." Low calcium levels can cause symptoms such as numbness around the mouth, tingling or cramping in the hands and feet, severe muscle spasms, inability to breathe, or heart rhythm (heart beat) abnormalities. Severe symptoms are life threatening, so it is important to start the management of these symptoms in the hospital. Treating low calcium levels sometimes require patients to spend a few extra days in the hospital.

The human body needs vitamin D to function and stay healthy. Vitamin D helps the body get the calcium needed to make strong bones and teeth. The purpose of this study is to determine if taking vitamin D before surgery to remove the thyroid gland affects whether or not you may have low calcium levels after your surgery and to test the hypothesis that those who are given the Vitamin D before surgery will have decreased hypocalcemia and a shortened hospital stay.

Inclusion Criteria:

• Patient referred for thyroidectomy
• Agreement to use contraception prior to and during the study

Exclusion Criteria:

• Hypercalcemia (>10.5mg/dL)
• Chronic kidney or parathyroid disease
• Cardiac or Central Nervous System disease
• Pregnant or breastfeeding women