We’re not going to rehash the benefits and frequency of deficiency of vitamin D here.  If you’re bored sometime, you can read all about vitamin D in past blog posts.  What we will review here is dosages and how mainstream medicine has been approaching the “vitamin D thing.”

First of all, lab values put normal levels of serum 25-OH vitamin D at 30-100 ng/dl.  It is widely excepted among experts in functional medicine that the optimal range is more like 60-100 ng/dl.

It seems like everyone is checking patients’ vitamin D levels these days, but the approach to deficiencies vary.  It is not uncommon for some of my patients to be told they have low vitamin D and put on 50,000 IU of the prescription form of vitamin D (ergocalciferol, or D2).  As high as these levels sound, they do not usually move blood values more than 10 or 20 ng/dl, most often leaving the patient still below optimal.

In our office, we generally start supplementation levels at 2,000 IU per day and move up from there depending on the clinical picture of the patient.  Our office uses an emulsified form of vitamin D3, which is very, very inexpensive, easy to take (can be taken once / week) and very high quality.  What more could one ask for??

However, when we recommend levels beyond 2,000 for specific patients, some are surprised at recommendations up to 6,000 or 10,000 IU / day, thinking this is a very high level (and yet don’t usually question the prescription, low quality 50,000 /  week, which is 7143 IU / day).

This particular article addresses the safety aspects of higher levels of vitamin D.  The author’s review concludes:

  1.  1500 IU is the lowest level needed to positively impact chronic disease risk
  2. Long-term daily intakes up to 10 000 IU of vitamin D do not show signs D toxicity

While it is not common that we recommend as high as 10,000 IU / day, it is considered safe with no signs of toxicity in the medical literature.

James Bogash

For more than a decade, Dr. Bogash has stayed current with the medical literature as it relates to physiology, disease prevention and disease management. He uses his knowledge to educate patients, the community and cyberspace on the best way to avoid and / or manage chronic diseases using lifestyle and targeted supplementation.


Please note: I reserve the right to delete comments that are offensive or off-topic.


  1. I frequently recommend 10,000 IU/day of Vitamin D–whenever someone tests under 30. We use Metagenics D–5,000 IU in one small oil perle that seems to be well absorbed. I myself started at a blood level of 30 and took 5,000/day for awhile, which only raised by level to 37 after 6 months. so I bumped it to 10,000/day and after a year my level had reached 75, so I dropped to 5,000. For some folks 5,000/day seems to be enough to optimize D levels, but much lower takes a long time.

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