Megadosing Vitamin D: Part Two

Megadosing Vitamin D: Part 2


It has been well established that higher serum levels of vitamin D are associated with lower risk of cancer progression and mortality, and many studies done on cancer patients have observed that vitamin D deficiency is clearly a risk factor for the development of certain cancers.

For example, a 2016 study found that women with vitamin D levels above 40 ng/ml had a 65% lower risk of cancer incidence, while another 2019 study, which followed end-term colon cancer patients, found those who increased their vitamin D levels experienced reduced symptoms. 

Now, cancer can be caused by many things including excessive exposure to toxins and radiation, and certain epigenetic factors, so vitamin D alone will not serve as a blanket protection against cancer. And, since it appears that a lot of what vitamin D does for cancer treatment is preventing metastasis (spreading), it seems to be more valuable at preventing cancer death than cancer occurrence. Nonetheless, there are many anecdotal cases of cancer patients going into remission after supplementing with high doses of vitamin D.

Brain Health

Low vitamin D levels are associated with many brain-related conditions including higher risks of Alzheimer’s disease, anxiety, autism,  depression, insomnia, and Parkinson’s disease. Since vitamin D regulates many chemicals in the brain it is also involved in memory and cognitive functions, processing emotions, and complex motor functions. (Source) Even brain fog can be a symptom of low levels of vitamin D.

According to Psychiatrist Dr. John J. Cannell, giving children with autism 5,000 IU of vitamin D daily, improved symptoms in nearly 80% of his patients. “My experience, having treated about 100 children with autism, is that 25 percent respond dramatically to high dose vitamin D, 50 percent respond significantly, and 25 percent do not respond at all,” he said.    (Source)

More Examples of Megadosing 

Dr. Patrick McCullough, referred to at the beginning of this newsletter, in 2019 published a report on the experiences of three of his patients who were taking high doses of vitamin D daily for years, with great benefits.

One of these patients began his high dose regimen eight years prior to the publication of Dr. McCullough’s report. Beginning with 10,000 IU per day, and ending up at 30,000 IU daily, this patient saw his severe asthma attacks reduced from five or six episodes yearly to only one episode between 2011 and 2019, and had stopped using most of his asthma medications.

Another of these patients had an ulcerated hand lesion, assumed to be a form of skin cancer, which shrank dramatically after taking high doses of vitamin D.

The other patient had extreme psoriasis across his ears, forehead, and  scalp, as well as, to a lesser degree, on his abdomen, chest, elbows, and thighs. He was given 50,000 IU of vitamin D daily, and soon saw a dramatic improvement, with full clearance after a few months of treatment.  (Source)

We have further data from a study called: “Daily oral dosing of vitamin D3 using 5000 TO 50,000 international units a day in long-term hospitalized patients: Insights from a seven year experience.”

Dr. McCullough is also one of the authors of this study, which included over 4700 patients, the majority of whom were prescribed either 5,000 or 10,000 IU of vitamin D daily. However, some patients, those with specific disease conditions, were prescribed much larger amounts, ranging from 20,000 to 50,000 IU per day. Of these patients receiving higher doses, “three patients with psoriasis showed marked clinical improvement in their skin using 20,000 to 50,000 IUs/day”. 

The fascinating thing here is that these physicians found no cases of hypercalcemia in any of their patients (or any adverse effects), even among those taking the highest doses. Hypercalcemia (high levels of calcium in the blood) is considered to be the major danger of taking too much vitamin D, and this danger is constantly touted when the conventional medical system warns us about self-prescribing vitamin D. 

Usually, in the field of natural health care, when we suggest levels of vitamin D above a certain level (for me it is over 5,000 IU on a consistent basis), we also suggest that one take vitamin K2, the simple way of preventing hypercalcemia from occuring. (Part of the job of vitamin K2 is to shuttle calcium from the blood into the skeletal structure.) 

This study concludes thusly: “In summary, long-term supplementation with vitamin D3 in doses ranging from 5000 to 50,000 IUs/day appears to be safe.”   (Source)

Back in the Day

Suprisingly, megadosing vitamin D is not a new idea. Back in the 1930s and 1940s high levels of vitamin D were being used by the medical profession for effective treatment of a variety of conditions including asthma, psoriasis, rheumatoid arthritis, rickets, and tuberculosis.   

Doses used to treat these conditions ranged from “60,000 to 300,000 IU a day for asthma, and 200,000 to 600,000 IU a day for rheumatoid arthritis”. 

Now, it is true that they found hypercalcemia occurring in some of those patients receiving the very high doses, but in those days they had no test for measuring vitamin D levels in the blood, and they had no idea how much vitamin D might trigger this condition.

We now know that a human can produce up to 25,000 IU of vitamin D daily with proper exposure to UVB radiation (sunlight, or therapeutic ultraviolet light), so clearly that level would be safe.

And, in 2011, a study on vitamin D toxicity found that hypercalcemia “resolved when 25-hydroxyvitamin D blood levels dropped below 400ng/ml in 2 patients with blood levels ranging from 645ng/ml to 1220ng/ml after accidental ingestion of massive doses of vitamin D”. 

In Dr. McCullough’s study of three subjects referred to above, “one subject took increasing daily doses of vitamin D3 for 6 years starting in April 2009: 6500 IU for 6 months; increasing to 10,000 IU for 13 months; 20,000 IU for 24 months; 40,000 IU for 12 months; 50,000 IU for 10 months, and 60,000 IU since October 2014”. Vitamin D levels in the blood were measured at these intervals and found to be 28, 81, 204, 216, 225, 166, and 218ng/ml, respectively. 

This is an amount of vitamin D that I would have considered insane, until reading the studies covered herein. Yet, “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”.   (Source)

In Which Things Get Even Crazier

I will close with one more mind-boggling study, the objective of which was “to evaluate the safety and efficacy of a single oral high-dose vitamin D3 supplementation in an intensive care setting over a one-week observation period”.

Performed at an Intensive Care Unit in Graz, Austria, this study followed the gold standard of research: randomized, double-blind, and placebo-controlled. 

Twenty-five patients (mean age 62 ± 16 yrs) with vitamin D deficiency [≤ 20 ng/ml] and an expected stay in the ICU >48 hours were included and randomly received either 540,000 IU of cholecalciferol (VITD) dissolved in 45 ml herbal oil or matched placebo orally or via feeding tube.”

And, guess what? That was a perfectly safe thing to do. This one time ultra-high dose of vitamin D corrected vitamin D deficiency in the subjects within two days without causing hypercalcemia or any adverse effects. And since many of these were critically ill patients, we can well imagine that having their vitamin D levels brought up to acceptable levels could well facilitate healing from almost any ailment or trauma. The doctors involved of course hope there will be further research to confirm their results and to discover if high dose vitamin D supplementation “can affect the clinical outcome of vitamin D deficient critically ill patients”.    (Source)


I have in the past touched upon the subject of methylation, and how this epigenetic malfunction can impact health. As it appears that perhaps 30% or more of us may carry this genetic malfunction, it is good to be aware that many of those with this genetic anomaly are also prone to having malfunctioning vitamin D receptors. This alone would explain a good portion of why some people only respond to very high doses of vitamin D. 

(When I am trying to quickly determine if someone may have a methylation problem, I simply ask them if they have been in good mental and physical health for most of their life. Those who have been generally well for most of their lives, usually do not have severe methylation problems. Those who have had difficult to diagnose health problems, such as chronic fatigue syndrome, Lupus, fibromyalgia, etc, or who have wrestled with mental health issues most of their lives, usually have methylation issues.)


I have already discussed the necessity of taking vitamin K2 if we are ingesting high amounts of vitamin D, as it serves to help prevent hypercalcemia from occuring. But there is one other essential nutritional co-factor required when taking high doses of vitamin D, and that is magnesium, a subject I have covered in detail elsewhere.

Magnesium, like vitamin K2, also helps deposit calcium in the bones, rather than in the arteries and soft tissues, both of them facilitating vitamin D absorption and working to prevent hypercalcemia. 

Finally, one would do well to follow the advice of all the professionals quoted above, who suggest that we have our vitamin D levels tested regularly if we are going to experiment with megadosing vitamin D.

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