I think it's the vaccines that have effected the gut in alot of cases causing problems with the impaired metabolism of vitamin D or any other minerals or vitamins.
An absorption problem as the latest research into autism has brought up the theory that vitamin D could be a cause in autism but I think people with autism have imparied guts more like Dr Wakefield's findings as...
This site says Several studies in countries with ‘western lifestyles’ have shown that over half of all babies are born deficient in vitamin D3.
Yet, half of all babies do not develop autism.

http://www.greenhealthwatch.com/newsstories/newsvitd3/vitd-babies-deficient.htm

As Rickets is among the most frequent childhood diseases in many developing countries yet how many autistic children were diagnoised with rickets at all during their well check appointments or even at there local schools pre- school and up?
And if it is one of the most frequent childhood diseases then how come those countries didn't have the first biggest rise of the autism epidemic because vitamin deficency has probably being going on in some parts of the world for decades and longer.
Plus as was reading that...
All formulas sold in the United States contain vitamin D.

http://www.aap.org/family/vitdpatients.htm

My babies did consume baby formula as well as breast fed.
They were not diagnoised with rickets went to all their wellness check appointments had their vaccinations and I believe that vitamin D could be a factor but more because of a gut absorption problem as my daughter with autism more recently..
Blood test showed she was vitamin D deficent so we have added a vitamin D3 capsules on top of all the other supplements she has already been on for years and we were totally shocked because..
She is outside all the time in the sun she loves the sun all she wants to do is swim and stay outside been that way for years in the sun and she was the last person we would think would be vitamin D deficent.
It must be an absorption thing which I believe was caused by those vaccinations and like what Dr Wakefield and others have seen in autistic children.
A neuro gut thing. If it was only as simple as just vitamin D but I don't think so.
And in early life they first got their vaccinations which may have started off the high prevalence of gastrointestinal symptoms, inflammation they see now.
Digestive problems and there progressive decline over time.
Physically sick! Thats what we have been saying all along!