Herbal Calcium Formula is a wonderful all natural calcium formula. It is a synergistic blend of the following herbs: Horsetail Grass, Nettle Leaves, Oatstraw Herb & Lobelia. As explained in the book, Biological Transmutations, the silica in horsetail grass converts to calcium. The other herbs work in close conjunction with this master calcium herb. We need calcium to help build strong healthy bones, teeth, hair, skin and nails, healthy eyes and for all calcium needs in the body. It is helpful for children as well as adults. Available in capsule, extract, and powdered forms.