That THEORY is that ms is caused by cell wall deficient germs and the whole problem is that your immune system is suppressed by vitamin D and causing thus the supposed infection to go wild...
and that if you decrease your vitamin d intake to deficient levels, like under 10, and at the same time take very high doses of benicar, an angiotensin (ARB) receptor blocker (usually used as a blood pressure medicine), this will activate your immune system and make it so super strong that the infection that causes MS will be relieved.
This theory is called the Marshall Protocol.
You can search this site for some "MS angle" information on it, but it is important to understand that the reason Trevor Marshall thinks benicar will activate the vitamin d receptor (while actual D will not) is from a computer model. He used this computer model to create all his theories, he is not a doctor, he is not even a medical professional, he is an electircal engineer with a PhD so he uses the term "doctor".
Please see this thread written by biodocfl who is a TIMS member who uses computer models to make new drugs (in legitimate pharmaceutical research).
Notice that biodocfl says that these models are well known to be unreliable and MUST BE FOLLOWED UP BY STANDARD RESEARCH TO VALIDATE THE SUPPOSED "FINDINGS". A computer model "result" is never taken as the truth until it can be shown to be true in real research.
In contrast, Trevor Marshall, an electical engineer whose field, EE, is entirely mathematical, puts out the incorrect notion that computer models are SUPERIOR to real reasearch. He claims regular lab research is "interpretive and prone to bias" while the computer models are "accurate".
While I believe it is possible for MS to be germ related, specifically Chlamydia pnuemoniae, the notion that it is helpful to reduce vitamin d intake to induce a clinical deficiency and that this will somehow help MS is dangerous to advance without rigorous studies, and I mean standard medical studies not an online group of people who are claiming success with no verification of that (it is well known that people who do not do well on the treatment are banned from the site and not allowed to post their experience).
Please be sceptical of this unproven theory. There is as JL said vast amounts of material supporting the addition of vitamin d to people with MS.
and as PX said this is an old idea, not an important advancement of any kind.