Look around the forum, do a few searches and you can see that we get this issue over and over again. While I agree that perhaps it could not be the light. I wouldn't risk it.
How often were you soaking previous to this? Yes you do need calcium however you also need a good UVB source for the animal to be able to absorb the calcium.
Now if this issue was happening to me I would switch out the light for an MVB, do daily soaks (with pedialyte if you'd like) , raise the humidity, and not let my temps drop below 80F.
I will look into the MVB. We would soak him minimum once a day and multiple times twicea day. I believe the problem came from how dry his tank was and not keeping it humid enough. As of yesterday I started to soaking him in pedialyte and doing it more often. The reptile store offered to take him and and do they best they can to nurture him back to health for me free of charge. Im thinking of taking him there today