Here’s a list of studies about the safety of high-dose vitamin D therapy:

Vitamin D Supplement Doses and Serum 25-Hydroxyvitamin D in the Range Associated with Cancer Prevention (2011)

Conclusion: “Universal intake of up to 40,000 IU vitamin D per day is unlikely to result in vitamin D toxicity.”


A Phase I/II Dose-Escalation Trial of Vitamin D3 and Calcium in Multiple Sclerosis (2010)

Conclusion: 49 patients were given large doses of vitamin D ranging from 10,000 IU – 40,000 IU daily for a year, achieved an average peak vitamin D level of 165 ng/ml (beyond what is currently considered safe), and experienced no significant negative side effects.


Vitamin D Supplementation and Regulatory T Cells in Apparently Healthy Subjects: Vitamin D Treatment for Autoimmune Diseases? (2010)

Conclusion: 46 healthy men and women were given 140,000 IU of vitamin D once a month for two months. Besides the average vitamin D level increasing from 24 ng/ml to an optimal 58 ng/ml at the end of the trial, the participants also experience a significant increase in their immune system’s regulatory T cells, demonstrating that vitamin D plays a critical role in proper functioning of the human immune system and helps protect against autoimmune disorders.


Self-Prescribed High-Dose Vitamin D3: Effects on Biochemical Parameters in Two Men (2008)

Conclusion: Two individual case studies. The first is a man who took 4,000 IU of vitamin D daily for three years and then took 8,000 IU daily for three years. During his intake of 8,000 IU daily his vitamin D levels remained in the safe range and he experienced no negative side effects during this time. The second case study is of a man with multiple sclerosis who increased his daily intake of vitamin D from 8,000 IU daily to 88,000 IU daily. While ingesting 88,000 IU per day he did experience some hypercalcemia and his vitamin D levels reached an incredibly high 450 ng/ml. For two months he then abstained from vitamin D supplementation and the side effects dissipated.


Risk Assessment For Vitamin D (2007)

Note: This article covers a number of experiments where daily doses of vitamin D ranging from 10,000 IU to 50,000 IU were found to be safe.


The Urgent Need to Recommend an Intake of Vitamin D that is Effective (2007)

Note: Article explaining why we need vitamin D doses higher than currently recommended by the medical establishment.


Safety of Vitamin D3 in Adults with Multiple Sclerosis (2007)

Conclusion: For 28 weeks, 12 multiple sclerosis patients were given weekly doses of vitamin D ranging from 28,000 IU to 280,000 IU. Although their vitamin D blood levels went far beyond what is currently considered safe, they experienced no negative side effects, and multiple sclerosis brain lesion activity decreased.


Why the Optimal Requirement for Vitamin D3 is Probably Much Higher than what is  Officially Recommended for Adults (2004)

Note: Article explaining why we need vitamin D doses higher than currently recommended by the medical establishment.


Randomized Comparison of the Effects of the Vitamin D3 Adequate Intake Versus 100 mcg (4000 IU) Per Day on Biochemical Responses and the Wellbeing of Patients (2004)

Conclusion: Two randomized trials where participants were either given 600 IU of vitamin D daily or 4,000 IU of vitamin D daily for three months found that those given the higher dose of 4,000 IU had better vitamin D levels and better well-being scores upon evaluation at the end of the trial.


Age-Related Changes in the 25-Hydroxyvitamin D Versus Parathyroid Hormone Relationship Suggest a Different Reason Why Older Adults Require More Vitamin D (2003)

Conclusion: Old people need more vitamin D.


Efficacy and Safety of Vitamin D3 Intake Exceeding the Lowest Observed Adverse Effect Level (2001)

Conclusion: Men and women were given daily doses of vitamin D ranging from 1,000 IU to 4,000 IU for 2-5 months. None of them experienced negative side effects.


Also see:


Multiple Sclerosis and (lots of) Vitamin D (2016) by Ana Claudia Domene details her experience over the last decade of successfully treating her aggressive multiple sclerosis with high-dose vitamin D therapy under the supervision of Dr. Cicero Coimbra and completely putting the MS into remission. The book also contains nine other case studies from some of Dr. Coimbra’s other multiple sclerosis patients who have been able to put their MS into remission with high-dose vitamin D therapy and even reverse their neurological damage from MS in two cases.



The Miraculous Results of Extremely High Dose of the Sunshine Hormone Vitamin D3 (2013) by Jeff T Bowles details his one year experiment of taking very large daily doses of vitamin D ranging from 25,000 IU to 100,000 IU daily with no negative side effects. The book also includes 26 testimonials, mostly from the book’s Amazon reviews, from other people who have had success with high-dose vitamin D therapy for treating chronic pain, depression, chron’s disease, lupus, psoriasis, atrial fibriliation, multiple sclerosis, plantar fasciitis, acne, asthma, obesity, sleep problems, joint pain, autism, cysts, and infertility.





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