When looking for a certain topic, you can always use the Search feature in the dark green bar at the top of the page. That will take you to any mention of the word used anywhere on the entire Dr. McDougall web site, including any newsletter article. You'll see the word "fasting" is used in many instances in treating various ailments.
Dr. McDougall has mentioned
how to fast a few times, but usually always in conjunction with True North Health Center, where a person is monitored 24 hours a day and visited by doctors multiple times each day. It's important to have vital signs and labs monitored if fasting, especially if you have various medical issues, and fasting does leave a person very weakened and prone to fainting spells and falls.
And in True North, not everyone is allowed to fast, either, depending on your medical history. Some are allowed to do water fasting for anywhere from a few days to a few months, other are on juice fasts, others just get healthy foods.
The only vitamin recommended by Dr. McDougall is B12.
As for the FOK app recipes - many of them are higher fat and not appropriate for people wanting to lose weight. You're currently posting to the Maximum Weight Loss forum - have your read the McDougall Program for Maximum Weight Loss or read the stickie on page 1 of the forum with the particular rules of the Maximum Weight Loss Program? Just following that version of the McDougall Program should help solve all your problems without resorting to something drastic like fasting.
Fasting for a day or 2 by yourself should be safe for most people, though. Not Dr. McDougall, but Dr Joel Fuhrman has a book out on fasting (
Fasting and Eating for Health: A Medical Doctor's Guide for Conquering Disease). His food plan is similar, but allows way more fat and less starch than Dr. McD, so the book is a good guide to how to fast, but use Dr. McD's for food advice afterwards. But if you do still want to fast for more than a day, your best bet is to do it in a facility like True North in Santa Rosa California. Other fasting places that follow the WFPB, no SOS (sugar, oil, salt) way of eating are Dr Gracie's Wellness Center in Ohio, run by Dr. Gracie Yuen and Ocean Jade Health Retreat in Florida, run by Dr Frank Sabatino. Both of those doctors previously worked with Dr. Goldhamer in True North and teach this way of eating.