Sunlight, Vitamin D, Covid-19 and Black Lives Matter…

The data is clear: people in ethnic groups living in the UK are more likely to die if they contract the SARS-Co-2 virus. Public Health England – currently being scraped and scape-goated to protect the government in its handling of the pandemic – concluded (Link 1) that BAME communities are more susceptible due to social deprivation. This certainly fits the current political narrative well but may not explain that poor clinical outcomes could simply be down to a lack of sunlight and low vitamin D levels. The PHE report “Beyond The Data” does identify a possible role for vitamin D but, as Lionel Shriver pointed out in the Spectator in June (LINK 2), this seems more an after-thought rather than heralded as a potential and important clinical cause.

Whether we have black skin or white skin, we too often forget, is only down to our genes and their ingenious ability to adapt us to the environments we choose to live in. Early man emerging out of Africa around 56,000 years ago most likely had black skin. As these small human groups moved further north they became, through genetic selection, fair-skinned. The reason for this was Vitamin D, created in the skin through the action of sunlight and vital for good health and fertility. At the latitude of the British Isles, darker skin meant less vitamin D and less vitamin D meant early death through myriad diseases and, in females, a greater risk of not being able to carry a child full term.

The role of Sunlight and its ability to improve health through production of Vitamin D, and other health vital chemicals for example Nitric Oxide (NO), is receiving renewed interest because of a possible link with poorer outcomes from Covid-19 infection. Current research is suggesting that the health implication of low vitamin D levels has much wider health importance (link 3). I have always stuck to government recommendations on vitamins and minerals and that is; eating a healthy diet provides sufficient for maintenance of optimal health. But it seems Vitamin D does not obey this rule. Vitamins are essential in that they cannot normally be manufactured in the body; Vitamin D can and our exposure to sunlight is key to maintaining a healthy level. Our diets too will help. Indeed, Inuit peoples living successfully in the Artic stay healthy with very little sunlight because their fish and seal-based diet is rich in vitamin D.

Some years back a link between obesity and low levels of Vitamin D was clarified; obesity causes lower levels of vitamin D (rather than the other way around) and scientists suggested that vitamin D, a fat soluble vitamin, may become ‘trapped’ inside fat tissue so that less of it is available to circulate inside the blood (LINK 4). As we know there is a direct correlation between obesity and Covid-19 deaths and people from Asian and Afro-Caribbean origin are more likely to have higher BMIs.

Vitamin D acts more like a steroid hormone than an enzyme catalyst which is the role of other vitamins and has a fundamental role in the regulation of numerous metabolic processes such as inflammatory response regulation. Most Covid-19 deaths are due to an exaggerated inflammatory lung response. Other diseases linked to low vitamin D levels include; heart disease, cancers and diabetes all identified as risks with Covid-19.

Living our lives in these cloudy northern latitudes ensures that, even with a balanced diet, we are unlikely to have sufficient vitamin D. Supplementation is important and is being more recognised by GPs and certainly is essential for ethnic minority groups especially those who have recently arrived from sunnier climes. And this supplementation will need to be much as much as four times the current daily recommended 400 IU. We seem to get much better benefit from sunlight produced Vitamin D that supplementation and this may be due to production of other chemicals such as the muscle relaxant nitric oxide; by the way how Viagra works.

We cannot ignore the potential benefit of sunshine but for years government campaigns have informed us that there is no such thing as healthy tan. There now, it seems, is justification to revisit this advice. Yes, sun exposure is linked to carcinoma of the skin yet where the prevalence of skin carcinomas diagnosis is growing year on year there has not been a similar increased in deaths due to the more dangerous types such as malignant melanoma.

Racism is obnoxious and Black Lives Matters protests have moved social equality a little closer and there remains some considerable way to go so that political narrative is important. This narrative should, however, be honest. As Lionel Shriver points out many Black doctors in the UK died of Covid-19 related symptoms and they were not from the lower socio-economic groups. We need to properly appreciate the real causes and their relative importance (Link 5). Social inequality is important but so too it seems are genetic differences that, when worked out, might be as important and more helpful in protecting Black lives.

LINKS

Link 1. Beyond the Data. Understanding the impact of Covid19 on BAME groups. Public Health England

Link 2. Lionel Shriver, Spectator June 25th 2020 A minority opinion on Covid deaths.

Link 3. http://www.wphna.org/htdocs/2011_aug_wn3_vitaminD.htm

Link 4. Vimaleswaran KS, Berry DJ, Lu C, et al. Causal Relationship between Obesity and Vitamin D Status: Bi-Directional Mendelian Randomization Analysis of Multiple Cohorts. PLoS One Medicine. Published online February 5 2013

LINK 5. https://www.thelancet.com/journals/landia/article/PIIS2213-8587(20)30268-0

Photo by JillWellington is licensed under CC BY-NC-SA