An adult with right aortic arch and dysphagia.

and 2000 IU. Both loading and maintenance doses may be folds higher to in thosewith increasing risks for the development or recurrence of vitamin D deficiency. Concurrent calcium supplementation is a key component of effective therapy, and a preventative strategy should always address underlying causes, if possible. In addition to maintaining sufficient serum 25-OH D levels, patients with end-stage renal and/or hepatic disease impairing vitamin D activation and resulting in hypocalcaemia, in addition to those with secondary hyperparathyroidism or hypoparathyroidism require activated vitamin D therapy (e.g. 1, 25-OH D2; 0.25– 0.5 mg/day). Patients with granulomatous disorders and dysregulated 1, 25-OH D2 activity may require vitamin D replacement, but 25-OH D levels .30 ng/mL can worsen the associated hypercalcaemia. Therefore, careful monitoring of vitamin D status, serum, and urinary calcium is necessary in these patients. Conclusion