Fragile bones and skeletal disorders

Calcium in Bones

Different hormones regulate calcium level in the bone matrix, which hormones and specify the one that is more important if any. Do they work together or antagonist toward each other?

Indeed, most calcium in one's body is located in one thing…bones. About 99% of all calcium in one's body is in the bones. There are three main hormones that are involved in the regulation of calcium in the body. Those hormones are parathyroid, vitamin D and calcitonin. Calcium movement in the blood is regulated by to main organs, one's gut and one's kidneys. Vitamin D comes from food and lack of it can lead to weakening of bones. Calcitonin is produced by the thyroid is used to lower blood calcium levels. By contrast, parathyroid is produced by the thyroid as well and does the opposite. So to answer the question, the latter two of those two hormones do act in an antagonistic fashion in that one reduces blood calcium levels and one does the opposite. Parathyroid tells the bones to break down calcium from the blood and into the blood stream while calcitonin directly attacks the osteoclast function caused by the other hormone. How these two hormones play off of each other varies based on a person's diet, how much vitamin D they have in their system and so forth. Keeping calcium at the proper levels is important because bone health, muscle health and nerve function all depend on it.

Hormones playing off each other and offsetting the effects of the other is definitely not limited to calcium regulation. Antagonists can be harnessed to help prevent bone loss but they can also be used to combat and affect other things. Just as vitamin D can be taken as a means to support healthy bone health (among other things), people often take angiotensin-converting enzyme (ACE) inhibitors and beta-blockers to help prevent hormones from doing something that is less than desirable for certain patients. It would be like blocking the calcium-reducing hormones so that the bone-building calcium hormones can do what they do without having to compete and offset what the blockers are doing.