I believe there is no direct relationship between the bitcoin and the Gold so there is no way that one is influencing the other. The Gold price is just decreasing because people no longer believes in it. It is becoming difficult to find pure gold and if you do, then you are always insecure,. who want to be insecure? also people are disposing them believing it is outdated form of storing wealth and storing wealth in investments such as real estate and other schemes.
There is a relationship between bitcoins and gold, and the reason is more people are switching to bitcoins only because it has very high price fluctuations as compared to gold, and people today wants a quick money and gold cannot give them quick money in trading and that is the reason people are trading more with bitcoins.