Inclusion Criteria:  • Patients 18 years and older who are scheduled to undergo total or completion thyroidectomy at the department of Oro-Rhino-Laryngology (ORL) and Head and Neck Surgery at Odense University Hospital, Denmark.  Exclusion Criteria:  Not legally competent. Does not read or speak Danish. Is pregnant or nursing. Suffers from chronic kidney disease with an estimated glomerular filtration rate < 45 ml/min/1.73m2. Has a history of allergy to iodides or to indocyanine green. Suffers from hyperparathyroidism, hypoparathyroidism, or hypocalcaemia prior to surgery. Prescription use of supplemental active vitamin D: dihydrotachysterol (ATC 11CC02), alfacalcidol (ATC A11CC03), or calcitriol (ATC A11CC04). Patients scheduled to have a radioactive iodine uptake study performed ≤ 7 days after the thyroidectomy.