Digestion can be a tricky thing. Not always our digestive system able to digest pills or the active ingredients as calcium from food. It stays in our body as toxins that create allergies. That is why for many people supplements in pills are not effective. It is better to have calcium from veggies and seeds. There is a new form of taking calcium which it make it easier for the body to digest it please check http://bodybonehealth.com/