A national, multicenter, randmised double blind study with parallell arms. 360 patients with grass induced allergic rhinitis will be open randomised 1:2 to 3 years Grazax sublingual immunotherapy or 3 intralymphatic injections with ALK Alutard Timothy. In a second step, the ILIT group will be double blind randomised 1:1 to an intramuscular injection of Vitamin D Vicotrat or placebo, 4 week before the start of the intralymphatic treatment. The primary outcome measure is daily combined symptoms and medication scores during grass pollen season.