A Study released in the British Journal of Nutrition 2014 https://www.ncbi.nlm.nih.gov/pubmed/24787048 showed that calcium supplements even in low doses was associated with an increase in brain lesions? These brain lesions it appears were caused by calcium build up in the arteries that led to ischemia of brain tissue. The problem was that the sources of many calcium tablets is derived from calcium carbonate, or shells of crustaceans, or eggs. These are inorganic forms of calcium that the body does not readily receive. In nature the way that the body obtains calcium and for that matter many of its minerals is through plants. See pure distilled water falls from rain and mixes on the ground as it runs over rocks and dirt and gathers inorganic minerals, these then feed the plants, which have the capacity to transform these inorganic minerals into organic minerals which we absorb. This is why we suggest people eat a lot of plants and especially green leafy vegetable matter when trying to get an easily assimilated source of calcium.