Thyroid Research Thyroid Research Archive Thyroid Surgery

Prevention of post-thyroidectomy hypocalcemia by calcium and vitamin D therapy

(March 2003)

The background of the study. Serum calcium concentrations can fall enough to cause symptoms (numbness and tingling of the hands, feet, and around the mouth; and muscle cramps) one or two days after thyroid surgery because of injury to the parathyroid glands. In this study the efficacy of routine calcium and vitamin D treatment for preventing hypocalcemia after total thyroidectomy was studied.

How the study was done. Seventy-nine patients were randomly assigned to receive calcium, calcium and calcitriol (a form of vitamin D), or neither, starting one day after total thyroidectomy. Treatment consisted of 1000 mg of elemental calcium three times daily, the same dose of calcium and 0.5 µg of calcitriol twice daily, or neither. The patients were examined and serum calcium was measured 1, 2, 3 (the day of discharge), and 7 days after surgery. Low serum calcium (hypocalcemia) was defined as a serum calcium value <8.0 mg/dl, even if it was present on only one occasion. Treatment was reduced starting on day 3 and stopped in most patients on day 7.

The results of the study. Among the 27 patients in the no-therapy group, 11 (41 percent) had symptoms of hypocalcemia, and were treated with calcium and calcitriol. In contrast, only 5 (10 percent) of the 52 patients in the other groups had hypocalcemia (and only two were given calcitriol). The average serum calcium concentrations were similar in the three groups (the values include the values for the patients who were being treated). The calcium and calcitriol treatment was stopped by day 7 in all but 8 patients and within the next 21 days in 6 of them.

The conclusions of the study. Treatment with calcium alone or calcium and calcitriol for 7 days after thyroidectomy prevents hypocalcemia.

The original article. Bellantone R, Lombardi CP, Raffaelli M, Boscherini M, Alesina PF, De Crea C, Traini E, Princi P. Is routine supplementation therapy (calcium and vitamin D) useful after total thyroidectomy? Surgery 2002;132:1109-13.