For now, she said taking flaxseed probably will not do kids much harm, but it is unclear whether it will help either.Flaxseed is a great source of B vitamins and fiber and that sort of thing, so as far as food value goes, it is certainly a heck of a lot better than eating a popsicle or Twinkie, said Demark-Wahnefried, who wasn't involved in the new research.