If you use egg shells for mg it is natural and very effective. Get a load of shells and wash them out to remove inner gunk then break them up into small pieces as you put them into a baking tray. Put them in the oven on medium heat and watch them until they start to brown off. Ideally some will be too browned off and help provide a little carbon too. Let it all cool down then grind Into a powder and add a teaspoon to your toppings initially. All natural and no risk.