Pre-operative Vitamin D often helps (thyroidectomy in this case)

Vitamin D Supplementation (100,000 IU) to Prevent Post-Thyroidectomy Hypocalcemia April 2026

Clin Endocrinol (Oxf). 2026 Apr 30. doi: 10.1111/cen.70152.

Objective: Hypocalcemia is the most common complication following thyroidectomy. Previous studies yielded inconsistent results on whether vitamin D3 prevents postoperative hypocalcemia and were conducted in non-European countries with different dietary habits and baseline vitamin D levels. Therefore, we explored the effect of preoperative vitamin D3 on post-thyroidectomy hypocalcemia in a Dutch cohort.

Methods: Patients undergoing thyroidectomy between 2023 and 2025 received 100,000 IU vitamin D3 1 week before surgery ("vitamin D group") and were compared to a historical cohort (2019-2022) without vitamin D3 supplementation ("control group"). Outcomes included incidence of hypocalcemia (albumin-adjusted calcium < 2.00 mmol/L), need for postoperative supplementation, time until normocalcemia, length of hospital stay, and readmissions.

Results: Fifty patients received preoperative vitamin D3 and were compared to 154 controls (82.8% female, median age: 55 years [IQR: 43-66]). Vitamin D3 supplementation was associated with a reduced risk of biochemical hypocalcemia at all postoperative time points (OR 0.28, 95% CI: 0.11-0.68, p = 0.005), corresponding to a number needed to treat of five patients to prevent one case of hypocalcemia. As compared to controls, the need for postoperative supplementation and time to recover from hypocalcemia were lower in the vitamin D group (32.0% vs. 53.9%, p = 0.007; and 0 [0-2] vs. 3 [0-11] days, p = 0.002, respectively). No differences were observed in length of hospital stay or readmissions.

Conclusions: Although larger randomized trials are needed to confirm these observations, preoperative vitamin D3 was associated with a significant reduction in post-thyroidectomy hypocalcemia in this observational cohort study. Given its low costs, this intervention may be considered for routine implementation in thyroidectomy patients.

Use of pre-operative calcium and vitamin D supplementation to prevent post-operative hypocalcaemia in patients undergoing thyroidectomy: a systematic review - June 2021

J Laryngol Otol. 2021 Jun 14;1-6. doi: 10.1017/S0022215121001523

A S Khatiwada 1, A S Harris 1

The amount of vitamin D given depends on the patient and the reason for the surgery 200,000 IU taken over a period of 2 -20 days is typical The Vitamin D should be taken at least 1 week before so that the levels have fully responded Giving vitamin D as the day of the surgery is not as good as given before, but is better than none at all A different form of Vitamin D can be given if the person has poor gut, poor liver, or poor kidney * Give Vitamin D before all spinal surgeries – no testing needed – June 2020 * Half as many problems if take Vitamin D (300,000 IU) before thyroidectomy – RCT Jan 2021 * Vitamin D is needed before many surgeries – many studies and RCTs

Objective: This systematic review aimed to establish the evidence behind the use of pre-operative calcium, vitamin D or both calcium and vitamin D to prevent post-operative hypocalcaemia in patients undergoing thyroidectomy.

Method: This review included prospective clinical trials on adult human patients that were published in English and which studied the effects of pre-operative supplementation with calcium, vitamin D or both calcium and vitamin D on the rate of post-operative hypocalcaemia following total thyroidectomy.

Results: Seven out of the nine trials included reported statistically significantly reduced rates of post-operative laboratory hypocalcaemia (absolute risk reduction, 13-59 per cent) and symptomatic hypocalcaemia (absolute reduction, 11-40 per cent) following pre-operative supplementation.

Conclusion: Pre-operative treatment with calcium, vitamin D or both calcium and vitamin D reduces the risk of post-operative hypocalcaemia and should be considered in patients undergoing total thyroidectomy.