Vitamin D levels are hard to diagnose. I also took the 50k Vit D but I read up that it was the crappy of the two kinds of D offered, so no surprise there that it didn't help much. I think the best way for you to actually get healthy and proper vitamin D levels is from the sun. It seems like manufacturing process gets shittier and shittier day by day, so who knows what you really get anymore, if it doesn't help at this point?
Try getting a tan more often or buying one of those special lights. After all, the skin will do its job but what money gets, well, we know what.
have a good one.