The Marshall Protocol has to do with Sarcoidosis.

His theory is unproven at this time.

I am unaware of a link between sarcoidosis and MS.???

more here:
http://en.wikipedia.org/wiki/Trevor_Marshall

The newest data on Vit D show that the majority of people improve in many ways when D is optimal in the blood.

The Sarcoidosis information remains unproven and controversial.
The recent extension of his PLAN to include so many other diseases, has a ring of hype to me. His newest claims seem over-reaching. His theories are in direct opposition to the newest research into Vit D.

Trevor Marshall is not educated in the biological sciences. He is an engineer.

There is a biological theory that ALL disease is triggered by infectious organisms. That each person has a different genetic capacity to handle invaders. This has to do with antigen/antibody responses, and I think that is far more complex than pinning it on Vit D. The vast majority of people in industrial countries are low in this nutrient. Not over supplemented as Marshall suggests. The amount of Vit D in our food chain is very small and also of the D2 variety which is not very biologically active.

It remains an interesting subject, however.