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).
The PTH system provides long-term, day-to-day regulation of calcium levels by many hormones working in concert. This hormonal âfeedback loopâ is governed by the parathyroid glands and the calcitonin secreting cells of the thyroid gland by their constant monitoring of the blood calcium levels.pecial cells that reside in the thyroid gland along with thyroid hormone containing cells release another hormone, calcitonin, into the blood. Calcitonin signals osteoclasts to slow down removal of calcium from bone; this action tends to lower levels of blood calcium.