The most important thing is to take your Runner Multivitamin with a meal containing some fat to absorb the fat-soluble Vitamins A, D, and E best. Aside from that, when to take the vitamins comes down to convenience.
I take my Runner Multivitamin, Joint Support (3 tablets), and Omega-3 with breakfast, where I typically have toast with nut butter, oatmeal, or eggs. I have found this routine works best for me. However, we have runners that spread their vitamins throughout the day with meals (breakfast, lunch, and dinner). Others take it only at lunch or dinner.
Best wishes on chasing your running goals,