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Information on the latest vitamin D news and research.

Find out more information on deficiency, supplementation, sun exposure, and how vitamin D relates to your health.

Dear Dr Cannell: No improvement with vitamin D

Dear John,

I’m writing you to keep you updated about the situation of my child, 7 years and 8 months aged, 24 Kg of body weight affected by autistic spectrum disorder NOS.

My son has increased the dose of vitamin D to 7,000 since April 7th as you suggested. He also replaced the 5,000 capsule with Bio Tech’s “D-Plus”.

Today he has performed the dosage of 25-OH vitamin D, and it resulted to be 100 ng/mL. Calcium, phosphorous, urea and creatinine are within the normal range.

His clinical situation is stable or maybe slightly improved but honestly, I cannot see a clear or a “step-up” improvement in the latest months.

I think he should reduce the dose to 5,000 or 6,000. Do you agree with me?

Moreover considering that in July we will take a mountain vacation for a week and a sea vacation on the next week, do you think he has to withdrawal (or further reduce the dose) in these 2 weeks and then start (or increase the dose) again once back at home? (Of course in these two weeks he will be exposed to sun for several hours of the day).

Thank you very much for your help.

Best wishes,

Professor Ronald Smith, MD


Dear Ron:

Does the child get any vitamin A in the form of acetate or palmitate, either in cod liver oil or multivitamins, or did he in the past? If so, get a vitamin A level and see if it is high normal.

I would reduce vitamin D to 5,000 IU/day or just the D-Plus capsules, and repeat his level in a month.

During vacation, if he is in the sun without sunblock and without many clothes during the hottest times of the day, he does not need supplements on those days. The days he does not do this during the vacation, give him 5,000 IU on those days. His shadow must be shorter than he is to make lots of vitamin D although it is still made when his shadow is twice his height.

With high normal vitamin D levels, you may notice his skin is less likely to sunburn than before, if he ever did.

Some parents report that it takes months to see an improvement so I would keep his vitamin D level in the high range of normal, around 80 ng/ml.

I would be surprised if he does not improve with lots of sun exposure in that many parents report seasonality to symptoms when asked and the sun may do more than simply make vitamin D.

Please consider videotaping him every thirty days, as sometimes improvements are slow and are not noticed by those who see the child every day.

If he does not improve on vitamin D in six months, he will be the first autistic child I have tried to help who achieved 80 ng/ml for six months and did not improve.


John Cannell, MD

  About: John Cannell, MD

Dr. John Cannell is founder of the Vitamin D Council. He has written many peer-reviewed papers on vitamin D and speaks frequently across the United States on the subject. Dr. Cannell holds an M.D. and has served the medical field as a general practitioner, emergency physician, and psychiatrist.

9 Responses to Dear Dr Cannell: No improvement with vitamin D

  1. John says:

    Why do you feel some people may not function better with over 100 ng? Toxic levels are over 200 ng for an extended period of time, right? Some people have reached 120 ng with sun exposure alone.

    • Brant Cebulla says:

      John, what study are you citing? I think the highest level on sun exposure alone known to date is about 90 ng/ml, but I could be mistaken.

  2. Wonder if the child is low on a cofactor important for utilization of vitamin D, such as MAGNESIUM http://www.vitamindwiki.com/tiki-index.php?page_id=3004

  3. I have seen too many autistic kids improve around 80 to think higher is needed. Cofactors can be crucial and autistic children are known to be magnesium and zinc deficient. I am quoting my own experience with our free autism/vitamin D program. UCSF is conducting a very similar open trial currently.

    I suspect this child will start improving in a few months if he is like many of the others.


  4. MaryT says:

    Dr. Cannell, I am glad to read that this little guy can still improve over time with vitamin D therapy. Sometimes maladies require time to improve especially with the treatment is nutritional therapy. Perhaps other issues are also being singled out by vitamin D such as intestinal issues. If the young man has digestive issues, these things must also be addressed. Does the child have issues with gluten and/or leaky gut syndrome or dairy? If these go untreated the vitamin D , I would wager, will have significant affect on the vitamin treatment and may hamper improvement. I recommend reading about the GAPS diet. The name of the authur does not come to me. It has helped many with these digestive issues. I hope this helps.


  5. hlwelborn says:

    John, your comment above about high vitamin d levels and lack of sunburn intriques me. After having repeatedly low Vit D levels (I live in Seattle) and doing my annual round of 50K pills, I started taking 5K doses daily last year. Although I am not using sunblock yet (steady, unabated sunshine doesn’t reach these climes until August, if then), there have been many days when my exposure would have normally produced a bit of a burn, but one never developed. What is the mechanism for this?

    • Brant Cebulla says:

      According to the chapter “Sunlight protection by vitamin D compounds” in Vitamin D Third Edition, vitamin D protects a little bit against sunburns by way of decreasing sunburn cells, protecting against DNA damage, and protecting against immune suppression.

      That is the simple explanation. The more complex explanation involves jargon in terms like JNK, Akt, ERK, Nitric Oxide, p53, metallothionein and sphingosine.

  6. Parent of autistic children report that vitamin D solves their GI problems. That is probably because vitamin D serves a “barrier function” all over the body, including the GI tract.

    Vitamin D and barrier function: a novel role for extra-renal 1 alpha-hydroxylase.
    Hewison M, Zehnder D, Chakraverty R, Adams JS.
    Mol Cell Endocrinol. 2004 Feb 27;215(1-2):31-8. Review.

  7. bacsithuy5@gmail.com says:

    p53 was mentioned as a possible factor which suggests Selenium involvement; have boron and sodium, as factors in absorption of calcium and magnesium from the gut, been considered. I look at these from a veterinarian’s perspective and another aspect i have at the moment is GEsoy in food;the glyphosate in GEsoy has been implicated in IBS-type symptoms in pigs with a possible detrimental effect on the VitaminD receptors in the villae of the gut. There is also the reduced levels of manganese,zinc,copper,iron and magnesium in GEs plants which could also be contributing to the spectrum, especially in USA where most soy is GE; we, here in NZ, are more fortunate (at the moment!)