<<Disclaimer: Verify this information before applying it to your situation.>> I asked whether any other celiacs suffered from canker sores and muscle cramps that went away after going GF. I received 27 responses that said they suffered from them and 23 suffered from muscle (leg) cramping. Most, like me, suffered from both. A significant number pointed out that canker sores and muscle cramping are most likely due to the malabsorption problem due to B-12 or other deficiency problems. Either way, just about everyone said they went away with the diet, as did mine.