Calcium and vitamin D metabolism in granulomatous diseases

Abstract

Overproduction of the active metabolite of vitamin D 1,25-dihydroxyvitamin D (1,25(OH)2D) has been described in sarcoidosis and other granulomatous diseases. High circulating concentrations of 1,25(OH)2D lead to increased intestinal absorption of calcium, possibly to enhanced bone resorption, and may result in hypercalcaemia and/or hypercalciuria. Data obtained in vivo and in vitro demonstrated that the unregulated production of 1,25(OH)2D lies within the granulomatous tissue and is controlled by glucocorticoids. This abnormal production of 1,25(OH)2D seems to be a general phenomenon of granulomatous processes, which is not exceptional in sarcoidosis, but appears seldom in tuberculosis. These abnormalities, however, are not pathognomonic of granulomatous processes, since they have been described in other diseases such as lymphomas.

Relationship Between Disease Activity and Serum Levels of Vitamin D Metabolites and Parathyroid Hormone in Ankylosing Spondylitis

“…It is known that glucocorticoids inhibit extrarenal 1a-hydroxylase activity, which results in low serum levels of 1,25(OH) 2 D 3 [22]. Because the patients were not receiving a glucocorticoid medication, other factors/mechanisms must be involved in the decreased levels of 1,25(OH) 2 D 3 in AS patients with high disease activity.…”

Hypercalcemia Due to Vitamin D Toxicity

“…There are several mechanisms by which calcium metabolism is disturbed in sarcoidosis [93]. First, 1,25(OH) 2 D 3 causes hypercalcemia, in part, by stimulating intestinal calcium absorption.…”

May 2016 critical care case of the month

“…Reports of hypercalcemia have been described associated with sarcoidosis, tuberculosis and other granulomatous disorders (4)(5)(6). Coccidioidomycosis is a an endemic granulomatous fungal infection found in southwestern United States and known to cause hypercalcemia when the infection is disseminated and involves bone (7)(8)(9).…”