Good time for an update! I do use Emergen-C. I also now take a multivitamin each night. I also am careful about getting into awkward positions at night- particularly sitting up in the tent at night and getting in and out of the tent. There are certain positions that I have learned to avoid because they always trigger cramps. Cramping has reduced significantly. My last trip I got really dehydrated (very hot and lots of sweating) and had a few cramps starting but was able to massage them before they got bad. I think the multivitamin has helped more than anything.