Why is eggshell calcium the better source of calcium?
As discussed above, eggshell calcium absorption into bone depends on the amount of elemental calcium being delivered, the ability of the calcium source to be digested, the true intake of calcium (after excretion), and facilitated transport of calcium to bone matrix. Eggshell calcium is unique in that it has a high elemental calcium level of 36–37% (500 mg of eggshell will provide about 180 mg of elemental calcium), it is more digestible than calcium carbonate (Schaafsma and Beelen, 1999) and has a high retention after excretion (>93 percent, Bao et.al., 1997). In addition, chicken eggshells have recently been found to contain inherent, low molecular weight proteins that enhance the transport of calcium across human intestinal epithelial cells (Daengprok et.al., 2003). This means that the transport of eggshell calcium across the intestinal wall may be superior to other calcium sources. The data also supports the results from Schaafsma and Beelen showing the high digestibility of eggshel
