I have read that the RDA for calcium is at least 800 mg. I know that a high level of calcium in the blood is not good.

"High blood calcium levels can be caused by eating a diet with excessive amounts of vitamin D, vitamin A, or calcium. Eating large amounts of milk products or taking too many calcium-containing medications (such as antacids or vitamin supplements) can cause high blood calcium levels."
Although excessive calcium intake has not been shown to be toxic, an extremely high intake of calcium in conjunction with a high intake of vitamin D can induce hypercalcemia. This condition can result in excessive calcification of bone and soft tissue (e.g., the kidney), or in the formation of kidney stones. "

For you women who are not yet menopausal, keep in mind that calcium slows the absorbtion of iron.
Its a balancing act, trying to get enough iron and calcium.