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).
Derangements of this mechanism lead to hypercalcemia or hypocalcemia, both of which can have important consequences for health. In humans, when the blood plasma ionized calcium level rises above its set point, the thyroid gland releases calcitonin, causing the plasma ionized calcium level to return to normal. When it falls below that set point, the parathyroid glands release parathyroid hormone (PTH), causing the plasma calcium level to rise.