Alumino-silicate content in calcium supplements derived from various carbonate deposits

This study measured the residue content in 19 brands of mineral supplements of which 9 brands were composed of dolomite and 10 brands were derived from fossilized oyster shells; referred to as "natural source" Ca supplements. The residues collected from 16 brands of the supplements were analyzed for their major constituents and were then compared to the chemical profiles listed for three marine sediment reference material (SRM) supplied by the National Research Council Canada. Aluminum concentrations were calculated and compared to previously reported A1 levels in similar products.