Calcitriol, the active form of vitamin D, is a powerful hormone that needs tight regulation in the body. It acts like a “key” that fits into specific “locks” (receptors) to manage important functions like calcium and phosphate balance. Too much or too little can cause harm, so the body carefully controls how much is made.
The body converts stored vitamin D (Calcifediol) into Calcitriol in the kidneys, but if Calcitriol levels get too high, enzymes slow down its production and break it down. Calcium and phosphate levels in the blood also help regulate this process.
Low calcium triggers the production of more Calcitriol, while high calcium or phosphate slows it down. Additionally, low phosphate increases Calcitriol, while high phosphate decreases it. These processes work together to maintain balance, ensuring proper calcium and phosphate levels in the blood.
If vitamin D stores are low, the body can’t produce enough Calcitriol, which can lead to health problems.