Yep, I didn't test exactly as a "deficiency" but I did have very subpar b12 and folic acid levels. Once I got on 5mg celexa, folic acid, and b12, things started to turn around big time.
As for vitamin C, I am not surprised. When I did a vitamin c thread search on one cfs forum last night, I saw a few people saying vitamin C helped them recover to pretty much almost normal, while others said it didn't help at all. As I think this is a viral disease, it may mean we simply have different viruses, or different stages of the same virus.
One thing about the vitamin C is the titration up of it. I felt like crap on vitamin C until I listened to my body and got down to a super low dosage and moved up super slow.