Figure 1From: Calcium affects on vascular endpointsParathyroid hormone (PTH)-calcium feedback loop that controls calcium homeostasis. Four organs-the parathyroid glands, intestine, kidney, and bone-together determine the parameters of calcium homeostasis. +, positive effect; -, negative effect; 1,25 D, 1,25-dihydroxyvitamin D3; ECF, extracellular fluid.Back to article page