Calcium is an important dietary mineral. A majority of the total calcium in our bodies is stored in our bones (99%). The remaining < 1% circulates throughout the body as an important ion in regulation of muscular function and blood clotting. The regulation of how much calcium is resorbed from the bone for use throughout the body is highly regulated by the hormones PTH & Vitamin D. Given its complex functions in the body, there is often a lot of confusion about dietary calcium intake and its effect on overall bone health.
I think we have all been told at one point or another that’s it is important to drink our milk if we want strong bones, and there is some truth to this. Although milk is not the only source of dietary calcium, it is important to maintain adequate calcium intake to prevent excess loss of calcium from the bones. When the bodies blood calcium levels fall to low, the body does three things to raise to calcium back to normal levels including: taking more calcium from bone, decreasing the amount of calcium you pee out, and increasing the amount of calcium taken in through the digestive tract (dietary calcium).
If dietary calcium is not maintained at a certain level the bodies ability to rely on calcium from the digestive tract is reduced which forces the body to take more calcium from the bone. If dietary calcium remains chronically low over time, the body must rely more heavily on calcium from the bones. This will, over time, decrease calcium stores within the bone. This is an issue because calcium is one of the major minerals that maintains the density and strength of bones.
When it comes to dietary calcium intake, like all things, it is good in moderation! Too little calcium over a long time can lead to weakening of the bones BUT too much calcium overtime and there are concerns of kidney stones. Note that although recommendations for a person over the age of 50 is 1200mg per day, most of this will be consumed through a balanced, healthy diet. Depending upon other factors, a healthcare professional may also recommend you begin a calcium supplement, but these supplements rarely need to exceed 500-600 mg/day.