Cal II is a source of high grade hydrated calcium oxide combines with yeast. The yeast was found to be a catalyst to make calcium's available in digestive reaction. Cal II is an anionic calcium and is used to direct digestive reactions in an anionic direction. This also means, that when calcium hydroxide, the resistance, affecting the speed of digestion, is being increased to improve digestion. Cal II is also considered a high energy anionic calcium (but not as high energy as cationic calcium) because of the Milhouse units of energy contained in each molecule. For that reason, it is best used with adults and those who are not in an extremely poor digestive situation. Be advised that there are other formulas that people try to equate with Cal II, but the Ream's Formula is the only one made according to Dr Ream's specifications, and the only one that works properly with the body's electrochemistry. The yeast in Ream's Formula Cal II was the onyl subtance that Dr Ream's found that would react with the hydrated calcium oxide. In Ream's own words:... "I found the calcium oxide had to properly combine with yeast for the body to accept the calcium. It was quite a job to get the calcium oxide to mix with the yeast without killing the yeast. Yeast is a plant and therefore breathes carbon dioxide, and I thought it would be easy to combine the calcium oxide with yeast, but it wasn't. To make a long story short, I found a way to do it, and today we have Cal II and the body accepts it readily. Cal II is my previous Cal Min (Calcium oxide) plus B2 and you have Cal II." In other words, Cal II is not Cal II unless it is made with yeast according to the Ream's Formula.