Vitamin D Toxicity- When You Take Too Much Vitamin D

vitamin D-SunExcessive vitamin D can cause a type of toxicity known as hypervitaminosis.

Sunlight destroys any excess vitamin D that your body makes, so it is impossible to get toxic levels of vitamin D toxic from too much sunlight. Because vitamin D is one of the fat soluble vitamins, it is theoretically possible to take too much as a supplement.  I have only seen one case of a vitamin D level over 100 ng/ml, which was in a child who the mom was mistakenly giving 10,000 IU daily for over two years.  That child had a level of 129 ng/ml and no negative symptoms at all.  The symptoms of Vitamin D toxicity are:

-Nausea and vomiting
-Loss of appetite
-Increased frequency of urination
-Weight loss
-Excess calcium 


The Mayo clinic points out that taking 50,000 IU a day on an ongoing basis can lead to these symptoms. See the report here.

Dr Michael Holick, author of the book The Vitamin D Solution, states, “you would need to ingest more than 10,000 IU of vitamin D daily for at least half a year to even begin to worry about potential toxicity from supplements”.  My own experience corroborates that point.  I was taking 5000 IU a day for almost 2 years when I went to my internal medicine doctor.  Now he happens to be open minded about nutritional supplements and a big advocate of healthy eating.  He was worried about my vitamin D intake so ordered a vitamin D level.  It came back 49 ng/ml  (I like to see levels of 50-80) but was as pleased with my level as he was shocked that it was not higher.  I then became lax about taking my vitamin D and probably took the 5000 IU once or twice a week.  Next time I checked my level a couple years later it was down to 19!

I had become deficient on what was clearly more than 1000 IU a day average intake.  I will add that at this point in my life I was not getting much sun exposure whatsoever.

Current recommendations by the NIH (National Institute of Health) and the AAP (Academy of Pediatrics) are totally inadequate and will not bring deficient levels into the optimal range. 

NIH Recommendation

AAP Recommendation

I recommend pregnant moms take 5000 IU a day and newborns at least 1000 IU daily (and that would include premature infants).  Parents have been safely administering these levels for years.  If you are unconvinced and if you are following my suggestions (which are for much more vitamin D than all the leading “experts” and academies) then you should have your level checked by a doctor before, during, and after many months of supplementation.

Dr. Paul

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