Vitamin D 100,000 IU daily was OK for Dr. Cannell for 6 months – Jan 2015

Highlights of email of Jan 29, 2015 (which is below)

Cofactors: not stated – but probably was taking Magnesium and Vitamin K2
350 ng after 6 months, no Calcium problems (cofactors?)
Sunbathing reduced the level to 250ng/ml
Was anxious so stopped the dose
Back to 100 ng/ml in 6 months


In 2012 I decided to do a toxicity study on myself to help answer a few questions.

I started taking 100,000 IU/day in June of 2012.

I measured my 25(OH)D and Urine CA/Cr ratio every week.
The 25(OH)D was run by two different methods.
Towards the end I also had a 1,25 and 24,25 run.

My 25(OH)D slowly increased to 300 ng/ml by LCMS at about 4 months.
My serum and urine calcium and urine CA/CR ratio remained normal.

I wanted to see if sun exposure would affect 25(OH)D so I started sunbathing an hour every day for 2 weeks.
My 25(OH)D levels decreased to 250 ng/ml despite the fact I was still taking 100,000 IU/day.
It seemed to indicate that sun exposure will help reduce elevated 25(OH)D levels.

By six months my 25(OH)D level was 350 ng/ml but my serum CA, 24 hour urine calcium and CA/CR ratios remained normal.

However, I started having anorexia and nausea (some symptoms of D intoxication) when I got to 350 ng/ml so I stopped the vitamin D.

It took about 6 months for my 25(OH)D to get under 100 ng/ml.
The anorexia and nausea went away in about a month.

The different methods of measuring 25(OH)D showed about a 25% variance on some measurements.
My 1,25 never went above normal but my 24,25 level was elevated the last 3 months.

It is assumed that toxicity is a side effect of hypercalcemia.
I guess the anorexia and nausea may have been psychosomatic as I got very nervous when my 25(OH)D got above 200 ng/ml.

This is. John J Cannell, MD, Vitamin D Council Inc.


See also VitaminDWiki

Graph of dose vs week

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