to add to JeffreyCH's list:
Hydration and compression sleves on the calves. Idk not a doc but my legs and feet always cramp the first few runs till about mid season...i think they call it building up lactic acid tolerance and the ability to flush it out. I always eat a banana, drink plenty of h2o, ibuprofen and compression sleves on the calves and it all helps. I also have high arch/instep and use ed vissures sole footbeds.