Vitamin D and Dyslexia
When I first wrote these pages on vitamin D3, I included a page preceding this one that laid out much of the recent research being done on vitamin D3 and it's correlation with many diseases and other health issues. Most of the links on that page to various videos and websites have since been disabled at their sources, plus it's become quite easy to use a search engine to investigate whether a vitamin D3 deficiency has serious health consequences and what they might be. Therefore, I've omitted that page. Here, I want to return to the hypothesis I raised in The Diet Piece of the Dyslexia Puzzle.
Could a Vitamin D Deficiency Cause Dyslexia?
Let me explain how I arrived at the point where it occurred to me to ask the above question. In 2008, I was already familiar with vitamin D3 as I was taking it myself and had been tested to ensure that I was getting Extending a vitamin D theory of autism to include dyslexiawhat I feel is the right amount for our Wisconsin winters. Over the course of a year or so I learned more and more about the effects of vitamin D3 on health and then one day I read a brief note linking a vitamin D deficiency to autism. This led me to Dr. John Cannell's paper titled Vitamin D Theory of Autism, a paper I'll discuss in some detail later. I should also point out that Dr. Cannell was publishing a theory, not a research finding.
As I said in The Diet Piece of the Dyslexia Puzzle I have felt for years that autism, Asperger’s and dyslexia, and possibly ADHD as well, are related conditions, with autism at the severe end of the spectrum and dyslexia at the milder end of a pattern of delayed development across several developmental abilities. Autism itself is, in fact, considered a "spectrum disorder" in which individuals display a wide range of varying symptoms but still fall within the formal diagnosis of autism. While Dr. Cannell does an excellent job of explaining his theory relating autism to Vitamin D deficiency, I wondered whether a similar case could be made for dyslexia (again, since I believe they could be related conditions across an even broader spectrum of developmental disabilities.)
Does Birth Month Relate to Dyslexia?
If a Vitamin D deficiency underlies autism (as Dr. Cannell theorizes) and if autism and dyslexia are related conditions (as I suspect), and if pregnant women in our northern climate become vitamin D deficient during the winter months (as Dr. Cannell claims is quite likely) then perhaps I would find some indication of that in my reading practice clients, many of whom exhibit the same signs as dyslexics in that they struggle to learn to read in the normal classroom.
It happens that over a particular period, most of my clients had also been treated for vision issues by undergoing vision therapy. I therefore took the clients in that period (extending over almost a year) and graphed them by month of their births. The reason I chose this group is because something physical (vision problems) could be construed as preventing them from reading fluently, rather than just poor initial reading instruction. What I found was quite startling.
Results by Birth Month
None of the dozen or so clients in that time period were born in the consecutive months October, November, December, January and February. All of them were born in the other seven months, with the largest concentration being in March, April, May and June. I was, frankly, astounded at this initial finding and proceeded to analyze my entire client base going back over several years and found that the five highest birth months of my entire client base fell in the five-month stretch beginning in March and ending in July. While this is obviously not conclusive evidence of a link between birth month and dyslexia, and certainly not between vitamin D deficiency and dyslexia, it did support my initial hypothesis that I would find a birth month pattern if autism and dyslexia and a vitamin D deficiency are all linked together in some manner.
So, What's a Parent of a Dyslexic Child to Do?
Based on what I've said above, probably nothing. All I've done, obviously, is crudely test a personal hypothesis and satisfy myself that I should keep an open mind on a link between dyslexia and a vitamin D deficiency. It would be nice if it were that easy, wouldn't it? And I did say elsewhere that I tend to be a "magic-bullet" sort of person, always looking for a simple, straightforward explanation to see if one can be found.
Even if dyslexia is not related to a vitamin D deficiency, parents should consider the other potential health benefits of vitamin D3 Nevertheless, whether dyslexia is affected or not by vitamin D3, so many other health issues have been related to a vitamin D deficiency that a parent would be foolish not to at least consider getting the entire family's D3 levels into the range recommended by the many researchers into the topic. And those same researchers have concluded that they can all agree on a level of 40-60 ng/ml. (Some want an even higher level to be reached, but they all agree on maintaining at least 40 ng/ml and they all agree that 60 ng/ml is not too high.)
I actually think Dr Cannell will eventually be proven correct and that autism will be found to be related, at least in most cases, to a vitamin D deficiency. I also suspect that I'm correct in linking dyslexia and autism as diseases along a spectrum of delayed or mal-development and that someone eventually will show that dyslexia is also related to a vitamin D deficiency.
Treatment Effect or Preventative Effect or Both?
Dr. Cannell's theory is aimed at prevention of autism, in that he hypothesizes that maintaining sufficient levels of vitamin D3 in both the mother during pregnancy and the child following birth and thereafter would prevent the onset of autism. He is less certain of a treatment effect. That is, he is less certain, but quite curious, whether a child already diagnosed with autism can be successfully treated with vitamin D3. He's certainly not willing to rule out the possibility.
Now, in the case of dyslexia, I too am theorizing a preventative effect, but frankly, I doubt that will ever be researched because dyslexia is a bit too poorly defiined. However, I do share Dr. Cannell's optimism about a treatment effect, only in my case, a treatment of dyslexia rather than autism. Essentially, i hope (and it's really just hope for now) that we eventually find that some dyslexia symptoms are reduced or even eliminated, at least in younger children, when vitamin D3 levels are increased to sufficient levels. Of course, since reading is a learned activity it's completely unrealistic to expect vitamin D3 to turn a poor reader into a good one. What it could do, however, is remove some of the blocks that are making it difficult for your child to learn to read. Regardless, the message I've tried to convey here is that you should consider maintaining adequate vitamin D3 levels for much broader health reasons, even if my theory relating dyslexia and a vitamin D deficiency is wrong.
On the next page, Vitamin D and Autism, I compare certain facets of both autism and dyslexia in an attempt to build a case that Dr. Cannell's theory of autism, if it proves to be true, might also apply to dyslexia.