The research protocol must give a clear indication of what follow up will be provided to the research participants and for how long. This may include a follow u, especially for adverse events, even after data collection for the research study is completed.
The two most important hormones for maintaining calcium levels in the body are parathyroid hormone (PTH) and 1,25(OH)2D (the active form of vitamin D).The major regulator is PTH, which is part of a negative feedback loop to maintain [Ca ++ ] ECF (see Humoral regulation).he two most important hormones for maintaining calcium levels in the body are parathyroid hormone (PTH) and 1,25(OH)2D (the active form of vitamin D).
Three organs participate in supplying calcium to blood and removing it from blood when necessary: 1  The small intestine is the site where dietary calcium is absorbed. 2  Bone serves as a vast reservoir of calcium. 3  The kidney is critcally important in calcium homeostasis.