Welcome to our little GERD corner of Healing Well!
I went looking for information and found two different results with very different takes on whether or not calcium helps with GERD.
Here's the one that definitely supports your hunch:
Here is one that actually posits that calcium can increase acid in the long run (look at the antacid section):
Hey, you're the best one to know if it's helping you! I have heard that calcium can help. In answer to your question, if it neutralizes acid then it is helping protect you.