CT is produced by the all-important thyroid gland, but its precise impact is relatively unknown as few symptoms arise with high or low levels. What is known is that it plays a role in regulating levels of calcium and phosphate in the blood and works in opposition to the parathyroid hormone. While it may be underrated, it’s also very old: there is evidence that calcitonin has been present since before our biological ancestors became land-dwellers. Despite these deep roots, there is still a lot to be discovered, but some research has been done studying the interaction of CT and collagen.