Normocalcemia in a Hypoparathyroid Patient with Sarcoidosis: Evidence for Parathyroid-Hormone-Independent Synthesis of 1,25 Dihydroxyvitamin D

Excerpt

Sarcoidosis may lead to hypercalcemia due to the increased levels of serum 1,25 dihydroxyvitamin D (1,25(OH)₂D) (1). This biologically active metabolite of vitamin D is produced by 1 α hydroxylation of 25 hydroxy vitamin D in the kidneys (2), a reaction normally stimulated by parathyroid hormone (PTH). A patient with postoperative hypoparathyroidism developed sarcoidosis and an elevated serum 1,25(OH)₂D level, resulting in a prolonged remission of hypocalcemia.

A 49-year old woman was hospitalized in May 1978 because of fever and precordial pain. The patient had had a subtotal thyroidectomy in 1953 for a diffuse, nontoxic goiter. She later developed tetany,