Rapid actions of vitamin D compounds

AbstractThe rapid actions of vitamin D compounds are surveyed in a variety of target tissues, including intestine, muscle, bone, hepatocytes, fibroblasts, HL‐60 cells, kidney, mammary gland, and parathyroid. Evidence for non‐nuclear receptors vs. membranophilic effects is discussed, followed by a consideration of signal transduction mechanisms including steroid hormone activated Ca2+ channels, phospholipid metabolism, protein kinases, and the role of G‐proteins.