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PTH secretion is inhibited additionally by the increased calcium uptake in the small intestine under the influence of biologically active vitamin D.
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The production of parathyroid hormone (PTH) in the parathyroids is inhibited directly by the biologically active form of vitamin D3. In the kidney, it inhibits the excretion of calcium and phosphate by promoting tubular resorption. The passive and active transport of phosphate is also stimulated. In the small intestine it promotes rapid and delayed calcium uptake. Pharmacology: Pharmacodynamics: In its biologically active form Vitamin D stimulates intestinal calcium absorption, incorporation of calcium into the osteoid, and release of calcium from bone tissue. Pharmacotherapeutic Group: Vitamin D, cholecalciferol.
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