Results of Daily oral Dosing with up to 60,000 International Units (iu) of vitamin d3 for 2 to 6 years in 3 adult males.
The Journal of Steroid Biochemistry and Molecular Biology, online 21 Dec 2016, http://dx.doi.org/10.1016/j.jsbmb.2016.12.009
Patrick McCullough a Patrick.mccullough at mha.ohio.gov , b, , , Jeffrey Amendb,
- Daily intake of high dose vitamin D3, 20,000 to 60,000 IU, was studied in 3 people.
- Daily dosing with these doses occurred over a 2 to 6 year period.
- Peak 25OHD blood levels were 225 ng/ml, 161 ng/ml, and 164 ng/ml.
- No adverse events related to vitamin D3 were noted in any subject.
- Blood calcium and intact parathyroid hormone levels remained normal throughout
In the 1930’s and 1940’s, vitamin D was reported to be an effective treatment for a number of diseases, including asthma, psoriasis, rheumatoid arthritis, rickets and tuberculosis.
High doses were used,
- 60,000 to 300,000 IU a day for asthma, and
- 200,000 to 600,000 IU a day for rheumatoid arthritis.
Toxicity from hypercalcemia occurred after prolonged oral dosing with these supraphysiologic doses. Assays for measuring vitamin D in the blood were not available, and blood levels of vitamin D associated with hypercalcemia were unknown. A 2011 report on vitamin D toxicity showed that hypercalcemia resolved when 25-hydroxyvitamin D (25OHD) blood levels dropped below 400 ng/ml in 2 patients with blood levels ranging from 645 ng/ml to 1220 ng/ml after accidental ingestion of massive doses of vitamin D.
We now know that vitamin D is made in the skin in amounts ranging up to 25,000 IU a day with exposure to UVB radiation. There is little data on the safety and blood levels of 25OHD and calcium after prolonged daily intake of amounts of vitamin D in this range.
In this report, one subject took increasing daily doses of vitamin D3 for 6 years starting in April 2009:
- 6500 IU for 6 months; 81 ng
- 10,000 IU for 13 months; 204 ng
- 20,000 IU for 24 months; 216 ng
- 40,000 IU for 12 months; 225 ng
- 50,000 IU for 10 months, 166 ng
- 60,000 IU since October 2014. 218 ng
Subject 2 began
- 10,000 IU in Nov 2011, increased to
- 20,000 IU in Feb 2014,
- 25,000 IU in June 2014, and
- 30,000 IU in Oct 2014, and then
- decreased to 20,000 IU in June 2015.
25OHD blood levels were 96.6, 161.1 and 106.9 ng/ml.
He reported marked clinical improvement in his asthma.
Subject 3 started on daily 10,000 IU in Sept 2013, increasing to 20,000 IU on Nov 2013. 25OHD blood levels were 31.4, 102, 164, 148, and 143 ng/ml.
No one developed hypercalcemia or any adverse events. The major finding of this case series is prolonged daily dosing of vitamin D3 with doses of 10,000 to 60,000 IU was safely tolerated.
Note: The authors were 2 of the 3 participants