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DarkHorse Sees The Light: Vitamin D and COVID-19

Updated: Jan 28, 2022

Dr Linda Benskin and I joined Bret Weinstein in this two hour DarkHorse podcast interview. We discuss vitamin D supplementation as a preventative measure for COVID-19, the science and the censorship, and our experience as scientists during the pandemic.

(TL;DR: All healthy adults should take at least 4,000 IU (100mcg) per day of vitamin D3. This is 10X the amount recommended by health agencies who base their recommendations on bone health, not immune function.)

How it came about

A few months before Christmas, Heather Heying wrote an incredible blog post saying that she and Bret had radically changed their position on vitamin D supplementation:

"In A Hunter-Gatherer’s Guide to the 21st Century, Bret Weinstein and I contend that the rush to supplement with vitamin D is yet another example of reductionist, metric-heavy thinking that passes for modern medicine and science. Our broader point stands... but... we (both Bret and I) now believe that we were wrong." [edited for brevity]

The willingness to change ones beliefs in the light of new evidence is the mark of a proper scientist. Heather not only changed her mind, but wrote a long, very well-researched blog post in which she strongly argues the case for vitamin D supplementation, something I've been campaigning for since the beginning of the pandemic.

Heather's post cites an excellent research article by Dr Linda Benskin, published early on in the pandemic, which reviewed the available evidence (nearly 200 papers) and firmly concluded vitamin D deficiency plays a key causal role in poor COVID-19 outcomes. One of those papers was the causal inference analysis preprint that I published in May 2020, a formal proof of the causal role.

Linda and I know each other, having connected through this research, and she's since published a more up-to-date review which she sent to Heather.

Linda and I have collaborated on a number of projects, including an Open Letter to all world governments,, which I co-organised with Dr Karl Pfleger, signed by more than 200 professors, scientists, medical doctors and PhDs (and two British MPs); as well as a Letter to the Editor condemning the litany of grave statistical errors in the flawed UK Biobank analysis by Hastie et al. which should never have passed peer review.

Bret and Heather have discussed science censorship many times on the DarkHorse podcast, and since we - like many members of the vitamin D research community - have battled an astonishing amount of censorship, we got in touch and Bret invited us on the show.

Links to resources discussed in the podcast - Over 200 Scientists & Doctors Call For Increased Vitamin D Use To Combat COVID-19

Vitamin D*Calculator - This app calculates the estimated additional Vitamin D intake needed to reach your target vitamin D serum level (40-60 ng/ml is recommended by our scientist panel). This calculates dose by weight and therefore suitable for adults and children.

Dminder App - dminder tracks the sun and tells you when you can get Vitamin D. based on season and sunlight (however, it may overestimate available UVB levels in winter, and in conditions of cloudy weather or air pollution). UVB at the required wavelength (around 297nm) can only penetrate the atomsphere if the sun is higher than 45° in the sky. It almost never is in winter outside the tropics - it may feel hot and sunny, and there may even be enough UVA to get a tan, but you won't be getting much, if any, vitamin D (unless you are high up a mountain where the atmosphere is thin and you are not wearing sunscreen).

The shadow rule for vitamin D is an easier way to quickly figure out if you can produce vitamin D in your skin naturally: if your shadow is sharp and shorter than you are tall, it's likely that there will be enough 297nm UVB in sunlight to produce vitamin D (sharp shadows imply clear skies, and if your shadow is shorter than you are tall then the sun must be higher than 45 degrees to cast it). However, do note also that glass, sunscreen (obviously) and melanin all block UVB too.

In fact, 11 conditions are actually necessary to produce vitamin D in naturally large quantities in the sun. Ten minutes of sunshine, as some doctors tell their patients, is almost never sufficient.

Frequently Asked Questions About Vitamin D - an excellent, evidence-based repository of information about vitamin D published by Grassroots Health.

Podcast Timestamps

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