In Scandinavia, far north of citrus fruit growing climates, the most important sources of vitamin C have always been berries: currants red and black, rose hips, elderberries, blueberries, gooseberries, lingon, etc.
I grew up eating elderberry soup, black currant dessert, you name it. Anyone with a strip of garden grows berries in Denmark. In our summer house garden grew five large black currant bushes and countless red currant and gooseberry bushes. Elderberry trees grow like weeds wherever you let them.
And in all of Northern Europe and the UK (they like to be mentioned separately) children and adults drink gallons of Ribena, a delicious black currant concentrate.
I suppose all that is not enough to prevent the occurrence of PD, but perhaps enough to slow progression somewhat. I think every claim made in Carolyn's post more than likely is correct. Berries are medicine.
Now that we're going to spend our summers here in Pennsylvania, we have planted red and black currants and gooseberries in our garden here. In a couple of years I can start making berry jelly and berry desserts. And as soon as I find a source for black currant pills I plan to take them.
Thank you, Carolyn, this is very exciting news.

birte