The Best Answer
Even too much of a good thing can be bad, in this case, vitamins, which can build up in your body over time. Taking excessive amounts of vitamins can be stressful on your liver, which is working overtime trying to filter out the excess stuff it can't absorb. Taking a day off gives your liver a chance to rest and flush out any excess vitamins before they become toxic. Think of it as a 'cheat day' for your liver.
Taking it 4x per day is a lot. If you look at the recommended dose on the bottles, most of them say to take 1-2 per day. On the Mega-Green Tea Extract, it specifically says 'DO NOT exceed the recommended dose'. So even though it's seemingly healthy stuff (garlic, tea, ALA, etc) it's good to give your body a break. I'm obviously not a doctor or anything, but it seems to make sense. It seems like cycling as a general philosophy tends to be good for you. I know body builders do it with protein too, and the book even mentions fasting (cycling caloric intake). If you forget, just take off as soon as you remember. Don't worry too much, you'll get so sick of taking it every day I'm sure you'll be happy to take a break!! I know I was!