ESC® brand calcium from eggshells is one of nature’s purest and most absorbable forms of calcium and comes from a natural, sustainable source – eggshells. ESC® naturally combines ultra-pure calcium with inherent transport proteins for maximum absorption and essential trace minerals for increased bone building support. ESC’s high elemental calcium (allowing for a smaller dose), and superior bioavailability provide distinct advantages over other bone health ingredients. Multiple clinical trials on eggshell calcium show effectiveness in supporting bone mineral density, some in as little as 4-8 months. ESC® naturally has extremely low levels of heavy metals – 50-100 times lower than California Proposition 65 and U.S. Pharmacopoeia limits when tested at 100% DV.