Vitamin D receptors and parathyroid glands.

To describe the function and metabolism of the vitamin D hormone and the role of the vitamin D receptor and the calcium-sensing receptor in the secretion of parathyroid hormone. A review of the literature was undertaken regarding the function and metabolism of vitamin D; the role of the vitamin D receptor and calcium-sensing receptor in the secretion of parathyroid hormone; and the contemporary research regarding the interaction of vitamin D and parathyroid hormone in patients with vitamin D deficiency, primary hyperparathyroidism, and secondary hyperparathyroidism. Over the last several years, great interest has been generated about the interaction of vitamin D and the parathyroid glands, gastrointestinal tract, kidney, and bone in relation to calcium and parathyroid hormone levels. Vitamin D has an important role in calcium and parathyroid hormone metabolism. Likewise, the vitamin D axis appears to be involved with the development of both primary and secondary hyperparathyroidism. The specific mechanism by which vitamin D interacts with the parathyroid gland to bring about observed effects is not yet fully understood. Future studies investigating the relationship of the vitamin D receptor, calcium-sensing receptor, and parathyroid glands are needed to enhance our knowledge of vitamin D deficiency and primary and secondary vitamin D deficiency.