I do not know [definitively] why he would "strongly advise against taking vitamin C if hair analysis shows 4 low electrolytes" but it may have to do with the fact that vitamin C is a good chelator of minerals when they need to be excreted., e.g. mercury, aluminum, lead, etc., etc. However, it also acts as a promoter of mineral absorption when they need to be absorbed.
Perhaps his fears have to do with the fact that, if a person continuously exceeded their Bowel Tolerance limit, i.e. thereby promoting too much [benign] diarrhea, they would, at least theoretically, have the potential of losing too many minerals in their "watery" discharge/stool.
My personal experience in this matter may be of some use/interest: I have ingested well in excess of 50+ grams of ascorbic acid every day for the past 20 years [that's over 900 pounds worth], and my health [at age 64] is what I would assume most people would call excellent, e.g. no sickness, doctors or drugs. If "mega-dosing" on vitamin C was harmful to one's [overall] health, surely I [of all people] would have a problem by now. But I can assure you, the exact opposite has been and is the case!
I hope this helps [as just "grist for your mill"], Pynegi.
This is from Acu-Cell. He does Cell Analysis to test for minerals. Not hair analysis. He observed the same thing that Wilson is worried about.
"the effect of a regular, daily overdose of Vitamin C is not an acute event as experienced with a deadly, toxic substance, but a gradual change in mineral ratios, or the progressive lowering of other essential elements, which over time can result in the development of moderate to serious medical problems"
Vitamin C is too good at removing metals and minerals, but it isn't smart enough to remove them in the correct ratios.
Dr Bates uses Vitamin C for Chelation. When doing so, he gives his patients mineral replacements. to attempt to make up for what it lost during chelation.
However, it seems optimistic that mineral replacement will be taken and absorbed in the same amounts that is being removed.