Sarcoidosis Case with Acute Renal Failure, Nephrolithiasis, and Hypercalcaemia After Uncontrolled D3 Vitamin Supplementation

Sarcoidosis is a multisystemic disorder of unknown aetiology, characterised by fibrosis and non-necrotising granuloma deposition. Typical presentation includes bilateral hilar adenopathy, skin, eye and articular lesions, pulmonary nodules, serum hypercalcemia, and nephrolithiasis. The authors’ case presented with hypercalcaemia and kidney stones after exogenous vitamin D use, who subsequently was diagnosed with sarcoidosis. Granulomatous diseases like sarcoidosis account for less than 10% of all hypercalcemia cases, and 10–20% of all sarcoidosis patients present with nephrolithiasis. The mechanism of nephrocalcinosis is related to vitamin D and calcium metabolism. Interferon gamma (IF-γ) and IL-2 are released from macrophages activated by T cells. Extrarenal 1-alpha hydroxylation occurs in granulomas, leading to elevation of active 1,25(OH) vitamin D. This causes increased intestinal calcium absorption and osteoclast activity, while tubular reabsorption of calcium decreases due to secondary parathyroid hormone suppression. Vitamin D replacement in this group is a controversial issue. Patients with multisystemic sarcoidosis are usually treated with intravenous methylprednisolone, which increases the risk of bone fractures. However, supplying vitamin D may also worsen hypercalcaemia in patients with sarcoidosis. Previous research indicates vitamin D supplementation may be given in select cases, if the 25-OH levels are low and sarcoidosis is in remission. In conclusion, serum calcium, 24-hour calcium, vitamin D levels, and disease activity should be monitored in patients with sarcoidosis who receive vitamin D supplementation.