HI Hobie and all,
When I think of NATURAL, I'm thinking fruit & veggie sources like camu camu which is pretty much the highest Vit C content for any source of NATURAL Vit C.
But when it comes to ascorbic acid there are synthesized versions and I believe only one natural or most natural ascorbic which still has to go through some form of extraction/synthesis process but is most prefered when making Lipo with ascorbic.
I found a Utube vid from Tony at herbsplusbeadworks where he talks a lot about ascorbic acid ... found it very in depth.
I included a link for it ... I only got a wee bit into the vid last night so gotta get back to it here.
As far as the 12 gram daily intake goes ... it will depend on how much ascorbic you used in one batch of Lipo and figure yer still gonna lose some on the way into your gut and more or less guesstimate how much Lipo to drink daily. I'm sure there are still some Utube vids out there where they give a rough estimate of dose vs strength of mixture for a good idea of how many grams you are taking daily. I'll do some more digging to see what I can find out. And don't forget, one can always supplement, along with daily Lipo intake, as many big horsepills ... 1000mg dose as you care to take. The worse thing that can happen if you take too much Vit C is the runs.

Journey