Listen to episode #127 of evolutionary radio ->
https://www.evolutionary.org/evolutionary-radio-episode-127/
We have Dr Gerry on as a guest and he is an expert on fasting.
You can continue to use all your regular supplements when on a fast - they just need to be non-caloric. That means you can't use things like protein powders, amino acids, fish oil etc.
Vitamin supplements are fine to consume.