Alleviate C contains the same dose of organic magnesium and boron as Alleviate with the addition of organic calcium. (Non swabbable) Calcium and magnesium are 2 of the 5 major electrolytes present in blood and body fluids. Blood levels of these vital minerals need to be kept at certain levels for life to continue. When the diet fails to supply adequate levels, the blood is forced to borrow them from other tissues. Calcium is released from the skeleton and magnesium is borrowed from muscle tissue including the heart. Too many horses are finished their useful life before they are 20. Demineralisation is not something that you can see happening from the outside and once it becomes obvious by the appearance of degenerative diseases, it is too late. Feeding top quality Vitamins and Minerals is the best thing you can do to promote a longer, useful life.