Vitamin D, skin color, Covid-19 incidence and severity

I’ve read reports that people of color are experiencing much higher rates of infection and severity from the Covid-19 virus. Here is an infographic that summarizes this concept.

Here’s a recently released video by a Harvard medical professor in which she discusses what she sees as compelling evidence about this association.

John Campbell, a PhD nurse from the UK, talks about his strong beliefs about Vitamin D and the Covid-19 virus.

Have you ever had the Vitamin D level tested in your blood? Most doctors don’t monitor Vitamin D. Are you taking any Vitamin D supplements?


Unrelated to Covid-19 a couple years ago I found out I had low Vitamin D. I’ve been taking over the counter supplements and test every 3 months to verify my numbers are in the normal range.

I’ve noticed a dramatic difference in how often I get colds. (I’ve had none in 2 years).

Prior to that I was getting multiple colds every year.

It’s cheap and safe. Also I’ve been watching a lot of Doctor Campbell’s videos and they are really great.

There are huge segments of the country that are always low Vit D. They cite Vit D correlations with everything. Its low hanging fruit - easy correlation to make because a large segment of the population is always low.

To graduate students with nothing to publish: Correlate vit D definciency with something. Anything. You will get a positive result. Publish a study correlating vit D deficiency with aquarium ownership. Correlate vit D deficiency with owning a chevelle. Note: A positive result is not always a meaningful result.

Vitamin D & Heart Problems:

Vitamin D & amputations:

Vit D & Breast cancer:

Vit D & psychiatric illness:

You can google anything and there will be a study showing correlation with Vitamin D. I hate it when researchers show vit D correlations. Its my pet peeve. Sorry, Terry.

Yes, I take Vitamin D, along with everyone else in my region of the country. It snows here for a large portion of the year. It snowed 2 days ago. We were all inside, hence the deficinency.

But, we do not all have the same skin color. Nor do we have higher incidence or severity of Covid. If we did, it would be due to the fact that we are all confined inside poorly ventilated buildings with other people to keep warm, not vit d deficiency.

I beg you to find one condition for which a study has not been published, relating it to vitamin D deficiency.

Sorry, again, for the rant.


No apology needed. I had no idea that Vitamin D was lassoed into so many contrived relationships! I simply made this post since a Harvard medical school professor commented on the possible connection of Vitamin D levels and the incidence of poor outcomes. I thought that this doctor avoided misleading the viewer with this quote.

We are in the process of planning a randomized clinical trial of Vitamin D supplementation with moderate to high doses to see if it does have role in the risk of developing Covid-19 infections and also reducing severity of disease in improving clinical outcomes.

I consider this source as a reputable one (as well as John Campbell) who is careful to acknowledge the scientific method and make the distinction between studies based on observational/epidemiological data and randomized clinical trials. This pandemic provides an interesting environment to learn and advance science.

I understand that associations and correlations do not mean causation, but I think the idea of Vitamin D sufficiency deserves more investigation. As a person who lives with diabetes, I choose to supplement with Vitamin D since I think there is likely some important immunological effect and I don’t enjoy the advantage of youth to allow me to wait for the scientific and definitive conclusion.

It’s possible there is a world wide general vitamin d deficiency and is in general bad for health.

I’m sure on average humans spend less time outside than they did 100+ years ago.

It’s interesting to note that both Australia and New Zealand didn’t experienced the degree of Covid-19 infection and death as many other countries, at least so far. Is it possible that their population having just completed a southern hemisphere summer when this virus spread gave them a certain degree of protection?

I know that is an unscientific observation and speculation but perhaps a randomized clinical trial on Vitamin D could prove or disprove that association.

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She should be ashamed of herself. Its not your fault. She should know better.
This is undergraduate work. She must be under pressure to publish something related to covid. It demonstrates a lack of integrity on her end. Vitamin D really gets my GOAT! But, you did remind me to take it.

You will currently see less flu activity at certain latitudes. I’m reading that as a result of temperature, like typical flu - either people are spending time outside or its less active in warmer temps. I’m hoping that in our summer months we see less activity, but we wont have that data for a while. Plus, the effect of that variable might get overwritten by others. Hard to say, but I’m being optomistic about it.

As a Minnesotan, I’m prone to attributing a lot of stuff to the weather - suicides, car accidents, crime rates, mental breakdowns, flu incidence, medical events, everything. I call it the Minnesota bias. We are a bit weather obsessed because it is a more influential variable here than other places.

Terry - I suspect that has more to do with the fact that it was summer (hot and for the most part dry) in Oz and NZ when the virus came onto the scene - remember the fires?

We’ll see shortly whether or not case density increases as they both go from fall to winter season.

People of color also have systemically less access to medical care (see story linked below for an example), are more likely to be essential workers in many places, and may also more likely to rely on public transit. Black individuals also have higher rates of T2 diabetes and hypertension, two of the biggest risk factors for death from COVID-19, aside from age. So many factors likely contribute to the racial disparities in COVID-19 deaths/outcomes. I don’t think Vit D deficiency explains the distinct racial disparities we see across many medical outcomes, such as with in maternal mortality for example (see link below), so I’m inclined to suspect other, largely social factors in racial disparities here more than I do Vit D.

Young Black woman in Brooklyn dies after being denied testing/treatment:

Racial disparities in maternal mortality:


I’ve been seeing endos for years, so yes, have had it measured, and have been taking a supplement for several years, now 2000mg x 3 per week, because of prior low-normal levels. I’ve read about the Vitamin D levels and SARS-CoV-2 from a Chinese study, but separately have read that supplementation doesn’t prevent CVD issues.

As it relates to race and ethnicity, the study considered basic risk factors, uncontrolled diabetes, HbA1c > 7.5, and age, deprivation. Note, this is the UK population so besides blacks, it also looks at those from a Southeast Asia, and those populations might be somewhat different than the people of the same country of origin in US or Canadian populations.

Covid-19: Known risk factors fail to explain the increased risk of death among people from ethnic minorities

Your conclusion may be true, but what if a study could be constructed whereby confounders like essential worker status, diabetes status, and public transit use were planned for so as to neutralize their effect?

It seems to me that since science has found that the white skin generates vitamin D more quickly than dark skin when exposed to sunshine, it follows that all other factors held equal would reveal higher vitamin D blood levels in lighter skinned people than darker skinned people.

So, If I understand the study you cite, it has taken into account basic risk factors (confounders) like diabetes, age and deprivation (Is that British English for poverty?) and concluded that blacks and people from Southeast Asia die in a greater percentage than white people in the UK.

I would like to see a study that added Vitamin D status into the mix.

In my experience as someone who conducts social science research, controlling for factors is not so simple. For example, if people who are Black are receiving worse medical care and worse outcomes due to provider biases that affect their medical assessment and clinical care, how are you going to measure and control for that? It could be done, but would require far more in depth analysis of medical records than simply using basic demographics. Those types of biases are not captured in measures of SES, but it absolutely could be part of the unique relationship between race and worse medical outcomes. So it’s a start to control for some measures of social factors, but you should be aware of the major limitations to those approaches.

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The only two that I’ve archived, although I know I read one from Chinese researchers, so bad Instapaper search. The first mentions Vitamin D, as well as a need for further study in regard to SES factors, and the second is an analysis by country which is part of the back-and-forth with @ChrisP.

Just a mention and I know you are already aware, but as @cardamom mentions, it is work, and presumably the right kinds of data, to disentangle aspects of SES, bias, and native biology.

BMJ: Is ethnicity linked to incidence or outcomes of covid-19?

To the latter point, about disentangling factors, is the higher vitamin D an outcome of culture, something genetic, or differences in social welfare policies.

I take no supplements. I have celiac disease, but have healed. My doctors always check my vitamin and mineral levels annually as a result. My vitamin D is always in range. Lower in the winter and a lot higher in the summer. I live in sunny Southern California. I exercise outdoors and do not wear sunscreen when walking or running as this occurs in the morning. I do wear sunscreen on long bike rides. When gardening, I wear protective clothing and a hat. My complexion is fair to medium.

I have encouraged my family members who live in colder climates to supplement with vitamin D (get their levels checked) or spent a few minutes outside each day.

As mentioned, race and ethnicity and tightly bound up in social effects and outcomes, and particulate emissions are just one more risk factor that aligns with COVID outcomes:

From this NYTimes update thread:

Health effects of living in poorer areas may align with the pandemic’s impact.

A linked publication:

Disparities in Distribution of Particulate Matter Emission Sources by Race and Poverty Status

I’m too lazy to find the detailed references right now, so I’ll just write some hints and whoever’s interested will do the “dry research” on their own.

  1. It has been claimed that that the doses of vitamin D and calcium compounds which are prescribed by most doctors for “osteopenia”, “low bone mass”, etc. are about half of what is really needed. For most people of ‘correct’ weight, the doses should be about 1 gm of calcium salt per day and 400 IU of vit. D per day. This shouldn’t be a problem if the blood level is being monitored correctly.

  2. IHBC that many overweight people will need much larger doses of vit. D, since the vitamin is being diluted over a much larger volume of fat.

  3. IHBC that there is (was?) a strong statistical correlation between “secondary osteoporosis” and high protein diets.

Maybe I’ll gradually add some real references. Until then, assume that I am lying, mistaken, or both.


  1. frinstance:

1a. Bischoff-Ferrari HA, Willett WC, Wong JB, Giovannucci E, Dietrich T, Dawson-Hughes B. Fracture Prevention With Vitamin D Supplementation: A Meta-analysis of Randomized Controlled Trials. JAMA. 2005;293(18):2257–2264. doi:10.1001/jama.293.18.2257

They are more or less recommending 800IU/day. " An oral vitamin D dose of 400 IU/d is not sufficient for fracture prevention."

1b. The Big Vitamin D Mistake
J Prev Med Public Health. 2017;50 (4): 278-281.
Publication Date (Web): 2017 May 10 (Perspective)

Look for yourself. I don’t even dare to copy the numbers they are talking about.

Enough teasers for no. 1.

CANTO-COSTA, M.H.S.; KUNII, I. and HAUACHE, O.M… Body fat and cholecalciferol supplementation in elderly homebound individuals. Braz J Med Biol Res [online]. 2006, vol.39, n.1 [cited 2020-05-19], pp.91-98. Available from: ISSN 1414-431X.

The exact opposite of what I wrote in no. 2 above. Do your own dry research.