Skin, hair & nail care

I wanted to talk about my experience today. If you remember, but you probably don't - I started to use Merz Spezial vitamins in June and I was so excited as I thought that they will work. My skin is not that bad, but my hair is really plan (you can read more about my hair here) and my nails are very fragile, so I was really happy and excited when I got these vitamins. After month using them I thought that my hair is finally looking healthy and my nails are stronger than they were. After 2 weeks when I stopped to use them all my worries was back - my hair was bad looking and my nails were fragile again. I started to use same vitamins again but this time I knew - they're not helping and it was my imagination that I thought that something is changing. I was really disappointed. Previous week was the last week when I used my vitamins and I was so annoyed that at the same time when I was using my vitamins I broke one of my nail and I had sooo long nails and new red nail polish to try. Of course I didn't try it because I love red nail polishes and it has to be special to try it, but now my nails are so short, that I feel like naked, haha. OK, I don't want to sound stupid, but I was so pissed - it's obvious that I wasn't expecting worlds 8th wonder but at least some changes?

Have you ever tried these vitamins before? What do you think of them?