Deficiencies in any minerals are dangerous! But I see you are once again using establishment misinformation to substantiate your argument! And what make you so sure these green leafy vegetables have any calcium in them at all??? If its not in the soil its not in the broccoli! And its a well known fact in alternative health that calcium supplementation is not the cause of these diseases but the lack of them that causes your body to draw calcium from your bones teeth and organs that causes these diseases! You lack of understanding this is your problem and the problem of others if they listen to your advice!