Alka® Tabs Calcium consists of calcium carbonate in pure form. The tablet dissolves in the intestines and enters the blood through the intestinal wall. There, by reaction with carbonic acid, calcium carbonate is converted into calcium bicarbonate, thereby increasing the alkaline buffers. Pure ionized calcium is also added to the body, which is good for the bones. Alka® Tabs Original is a tablet that already consists of sodium bicarbonate and potassium bicarbonate. This is directly absorbed into the blood via the intestinal wall. For people who are not allowed to have sodium or potassium, or people who suffer from osteoporosis, Alka® Tabs Calcium is a good choice. Alka® Tabs Magnesium consists of magnesium carbonate in pure form. The tablet dissolves in the intestines and enters the blood through the intestinal wall. There, by reaction with carbonic acid, the magnesium carbonate is converted into magnesium bicarbonate, whereby the basic buffers are increased. Pure ionized magnesium is also added to the body. Alka® Tabs Magnesium is a good choice for stress, muscle complaints or insomnia.