first water fast :)

hi everyone!

after some research about fasting I finally decided to start one last night at 12am to ring in the new year fresh & pure!

I want to ensure I do this right & stay healthy though so I have a few questions if anyone can help me out...

1) can I still take my vitamins or will those disrupt the ketosis?

2) I'm 18, about 5'6, 138 lbs... I'm not doing this to lose weight really, just to detox, but I'm scared that once I break the fast that I'll gain weight I lost back and get stretch marks. is there any way to avoid gaining the weight back really fast? how do I space it out? I reeeaaally don't want anymore stretch marks.

3) does this have any affects on the hair? have any of you noticed hair loss or dryness or anything of that nature?

okay thanks so much to anyone who can help me. almost finished day one & feelings great so far!!