I've been overweight all my life, with some temporary successes reducing my weight, but all that weight kept coming back with a vengeance.

This April I decided to try again, and cut out all sugar and pastries from my diet. And in May I discovered "The Complete Guide to Fasting" by Jason Fung MD, and this book has been absolutely transformative. I revamped my diet completely to go high-fat low-carb, and started practicing fasting.

My current weekly routine is water/tea only fasting for two days, eating for one day, then fasting for three days, then one day of eating. Rinse and repeat. Been practicing it for several weeks now, in my first two weeks I went from 117kg to 110kg, which was great. But then my weight plateaued and for the last two weeks it's been bouncing between 110kg and 113kg. I understand that it's mostly water and food in my digestive tract, so the swings don't bother me. What does is not seeing new minimums while maintaining a regime that's expected to give me roughly -1kg of pure fat per week.

The book I mentioned above suggests increasing fasting durations in this case, e.g. 1-week fasting or 2-week fasting. It also mentions that, apart from regular electrolytes (which I'm already supplementing on fasting days), it's recommended to take "regular poly vitamins". And this is where I'm getting confused.

Instructions for most vitamins prescribe taking them on a full stomach, most probably because those vitamins are fat soluble and not having any fat in your digestive tract would drastically impact the absorption. Separate concerns exist for vitamin mineral complexes containing iron, as taking iron on an empty stomach may result in ulcers.

So how do I go about all this? Is there a way to take vitamins efficiently while not eating anything for a week? Same goes for fish oil, which is also supposed to be taken with or after a meal.