ization . ▁ ▁High ly ▁por ous ▁A CC ▁High ly ▁por ous ▁A CC ▁has ▁been ▁synth es ized ▁using ▁a ▁sur fact ant - free ▁method . ▁In ▁this ▁method ▁Ca O ▁is ▁dispers ed ▁in ▁m eth an ol ▁under ▁a ▁pressure ▁of ▁carbon ▁dio x ide ▁in ▁a ▁se aled ▁reaction ▁vessel . ▁A CC ▁with ▁surface ▁area ▁over ▁ 3 5 0 ▁m 2 / g ▁was ▁synth es ized ▁using ▁this ▁method . ▁High ly ▁por ous ▁A CC ▁appeared ▁to ▁be ▁made ▁up ▁aggreg ated ▁nan op articles ▁with ▁dimensions ▁less ▁than ▁ 1 0   nm ▁in ▁size . ▁High ly ▁por ous ▁A CC ▁was ▁also ▁found ▁to ▁be ▁stable ▁in ▁ambient ▁conditions ▁for ▁up ▁to ▁ 3 ▁weeks ▁with ▁most ▁of ▁its ▁por os ity ▁retained . ▁ ▁App lications ▁and ▁uses ▁Bio av ail ability : ▁Since ▁ 2 0 1 3 ▁a ▁company ▁named ▁Am orph ical ▁Ltd . ▁s ells ▁an ▁A CC ▁di et ary ▁supp lement . ▁Cal ci um ▁carbon ate ▁is ▁being ▁used ▁as ▁a ▁calci um ▁supp lement ▁world wide , ▁however , ▁it ▁is ▁known ▁that ▁its ▁bio av ail ability ▁is ▁very ▁low , ▁only ▁around ▁ 2 0 – 3 0 %. ▁A CC ▁is ▁roughly ▁ 4 0 % ▁more ▁bio available ▁than ▁cry st all ine ▁calci um ▁carbon ate . ▁ ▁D rug ▁delivery : ▁Due ▁to ▁the ▁ability ▁to ▁t une ▁the ▁size ▁and ▁morph ology ▁of ▁the