On Fri, 3 Dec 2010 08:44:56 +0100 in rec.food.cooking, "Giusi"
> wrote,
>Born and reared in Maine, and we always had vinegar with greens. Recently
>it was published that many nutrients in greens are not released without the
>presence of vitamin C which is in vinegar. It's in lemons, too, but lemons
>don't grow in New England.

There is no vitamin C in white vinegar. There may be some small
amount in some specialty vinegar, but I would be surprised.

Perhaps the acid of the vinegar itself has the effect you describe.
Which nutrients?