The bones are our largest reservoirs of calcium, containing about 99% of the calcium found in the body. Calcium—in the form of calcium hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂)—is also found in the teeth, in the circulatory system, in the muscles, and in other tissues. But how much do we really know about the stuff?
Calcium plays a crucial role in the body. The vital mineral helps to regulate the blood vessels, oversees our hormone production, and is key to our intracellular signaling—or the way the cells communicate. It’s also involved in our muscle contraction, nerve communication, and other functions.
What does this mean? First off, in the human body, calcium homeostasis—and by extension, calcium resorption and bone formation—is paramount to our overall well-being.
Second, we need to pay close attention to the factors that influence calcium absorption, bone formation, and homeostasis. These include diet, exercise, vitamin D3, thyroid (TH) and parathyroid hormone (PTH), and age. When these factors are out of balance, calcium homeostasis is affected—and disease states such as calcification (the accumulation of excess calcium), osteoporosis, kidney damage, p53 dysfunction, the POT1 gene, and various cancers by DNA mutation may occur.
Depending on the underlying abnormality, there are a number of treatments available. To understand them—and the complexities surrounding homeostasis—it’s essential that we review the different levels of calcium, and the importance of homeostasis in our calcium absorption.