The official medical establishment rda for d3 is 800iu a day. The toxicity of taking too much d3 is a scare tactic started by the drug industry to keep people sick from not getting enough. D3 is key in having a healthy immune system and preventing cancer and 80/90% of people are deficient in it especially in the nortern hemisphere. Pharmaceutical companies control the medical education system in this country and the governing boards so not following their protocols will get hospitals/doctors licenses pulled as happened during covid if you were paying attention. Treating the symptons and not the root cause is how the whole system is designed. D3 deficiencies from not enough time in the sun, poor absorption and poor food quality all contribute. If you have a serious health problem 40 to 50 thousand iu's a day is the amount needed to stop/and begin to reverse the health problem such as auto immune diseases and cancer. The person I replied to had systemic inflammation throughout the body. Building up the immune system is best way to begin to reverse the symptons and it all begins with D3. You need K2 for D3 and Magnesium and Zinc as well. Most people are deficient in all of them and they all depend on each other to work properly. People have been fasting for centuries not only for religious reasons but health related reasons as well. Intermittent fasting is relatively easy were you consume your food in a 8 or 6 hour window and only water, tea or coffee the rest of the time with no sweetners or cream. I started doing this a few years ago and it has been very beneficial. I do a prolonged fast once a year and it is a eye opening experience after which I feel rejuvenated. I did 5 days last year and had my glucose checked at the beginning and end. Started in the low 90's and ended in the low 70's. I am not currently on any meds and in my 60's but type 2 diabetes is prevalent in my family. If your a diabetic that would certainly be a problem especially for type 1. Type 2 might be able to do Intermittent but not prolonged. If you go to the references I gave they are the best sources I have come across to date in 17 years of studying health and diet.