I agree Chris and of course I fast without supervision and support others here to do the same if their situation doesn't allow for supervised fasts. Just do it! However fear is of course one of the contraindications of fasting and if you can't get over a specific concern about having enough vitamins or electrolytes or minerals or whatever while fasting, and it is something you are still afraid of in spite of researching and our reassurances here, the safest option would be to consult a professional.