i eat cucumbers,tomatoes and onions regularly but this is probably not reach the daily need for at least 90 mg.but i used to eat also red bell pepper with my vegtebales 3 a day,so this should had given me enough vit c but it didn't do something like the red pomelo did.maybe the vitamin c is preserved more in red pomelo than in those vegtebels.
i founf that D-glucaric acid is sell as a supplements, it is call Calcium D-Glucarate, maybe i will try it in the future.