Open letter in several publications, like Shetland Times

Vitamin D3 and a global exit strategy from COVID-19

While the world is on hold as COVID-19 accelerates its global rampage, an exit strategy seems many months away. Herd immunity is a distant prospect, as are vaccines or drug treatments. However, there is a measure with the potential to help in this crisis at the cost of about 1p/day per capita, that would promote our defences, vitamin D3. This steroid hormone promotes the innate immune system, our first line of defence against microbes, including corona viruses, but the UK population is commonly D3-deficient, often severely, as is also common globally. We suggest, therefore, based on the accompanying scientific and medical evidence that efforts be made to improve vitamin D repletion to help reduce both morbidity and mortality from, and perhaps also susceptibility to, COVID-19.

We are chronically undersupplied
Vitamin D (D3) is the sunshine vitamin. Our skin makes it under summer sun but most British people don’t make enough because we live and work indoors, live at high latitude and eat little ‘wild’ oily fish (the only good food source of this vitamin), while deficiency is also a global problem.

Scientific evidence from peer reviewed publications shows that vitamin D is needed both for healthy bones and for a healthy immune system which can defend us against most bacteria and viruses at adequate blood levels of the vitamin D metabolite 25(OH)D by gene modulation, and that also reduces inappropriate inflammation.

What is an adequate blood level of 25(OH)D?
25 nmol/l was thought enough until 20 years ago, now we know it should be more than 50 nmol/l, a target used throughout the NHS. Higher levels are advised by many experts at 100 – 150 nmol/l, for optimal health (1), as are achieved by natives of the tropics.

We have a high degree of deficiency, worst in Scotland
One third to a half of all people are deficient across the UK, with severe deficiency increasingly common in the North.

Benefits of supplementation
In addition to the prevention of rickets and osteomalacia, and reduction of the risks of increasing numbers of chronic disorders, both survival with cancer and the risk of getting certain cancers are reduced by better vitamin D status (2-6).

Respiratory infection rate reduction
Evidence from animal, cell and molecular research shows that lack of vitamin D increases the risks of many chronic diseases; supplementation of deficient people can reduce many such risks, including upper respiratory tract infections as shown in a summary of 25 studies where deficient subjects amongst 11,000 participants supplemented with vitamin D showed over 70 % reduction in infection rates with certain common viruses. (7). A recent review concludes: “To reduce risk of infection, it is recommended that people at risk of influenza and/or COVID-19 consider taking 10,000 IU/d of vitamin D3 for a few weeks to rapidly raise 25(OH)D concentrations, followed by 5000 IU/d. The goal should be to raise 25(OH)D concentrations above 40–60 ng/ml (100–150 nmol/l).” (8) Those authors called for randomised trials of vitamin D in COVID-19 patients. Meanwhile, the evidence justifies ensuring that COVID-19 patients are not deficient, measuring serum 25(OH)D where possible, but more importantly, ensuring adequate supplemental intakes for all such patients. (9).

Barbara Boucher, honorary professor, London
Peter Cobbold, emeritus professor, cell biology, Liverpool
David Grimes, retired consultant physician, Manchester
Helga Rhein, retired general practitioner, Edinburgh


other campaigner’s letters:

30/5/20  Anne Thomas 30:5:20 to Covid Committee

5/5/20  Andrew Craigie’s letter to Dr Gregor Smith.5:5:20 docx

Edinburgh, 5/8/2020

Dear First Minister, Health Ministers, Chief Medical Officers and Public Health Consultants,

Congratulations to the significant achievement of low Covid-19 infection rates and very low mortality figures of the last few weeks in Scotland. Good leadership was surely instrumental here which means the population trusted the leadership and followed your advice,  I think all of us in Scotland are deeply grateful for that, and proud of you.

Over the last few months myself and others have been speaking up about the need to recognise the UK wide health problems linked to vitamin D deficiency because of its significance to the immune system. Due to latitude and climate vitamin D deficiency is a bigger problem in Scotland. Various letters, blogs and snippets on social media had been written, some are on the pages of the website below.

I have worked as GP for about 35 years in deprived areas of Edinburgh until my retirement two years ago. During the last 15 years I treated many of my patients for their vitamin D deficiency and observed significant improvements with vitamin D supplements. Amongst these improvements were: fewer chest infections in COPD patients, reduced frequency of colds and coughs, less depression, fewer pains, less tiredness, fewer symptoms of inflammatory bowel disease, better cancer survival etc. It became clearer as time went by that most of my patients suffered to a larger or smaller degree of vitamin D deficiency and eventually all patients received routinely repeat prescriptions for vitamin D, the results were excellent.

Vitamin D deficiency is always less of a problem in summer. This is most likely the reason why influenza and other infections show a seasonal pattern. A well functioning human immune system is dependant on being well supplied with vitamin D, either through sunshine, diet (oil-rich fish) or supplements.

However, it does take some months to build up an adequate vitamin D blood level associated  with a well functioning immune system and that is why I am writing to you today.

I would like to urge you to consider a population wide supplementation program, preferably through adequate food fortification, ahead of the next winter, so that the population’s resilience can be strengthened well in advance of the inevitable increase in infection rate in the winter ahead, when people will be more indoors again and have reduced access to UV light resulting in lowered blood vitamin D levels. With less D-deficiency there is a realistic chance that the likely increase in Covid-19 infections might stay a mild infection, rather than lead to severe outcomes.

Although we have no randomised controlled trials yet to prove that optimal vitamin D levels in the population will reduce mortality of Covid-19 infections,  a decision to reduce our widespread well documented Scottish vitamin D deficiency, should be based on the precaution:
But harm to the immune system is caused from insufficient vitamin D provision.

Food fortification would guarantee that ALL people in Scotland have a better supply of vitamin D, including those living in deprived areas, who have a higher Covid-19 mortality as well as higher prevalence of vitamin D deficiency. In fact the high risk groups for Covid-19 mortality are overlapping with the high risk groups of severe vitamin D deficiency: people with dark skin types, those overweight or older.

The Scottish Government, along with UK advisory bodies, has suggested to take 400 IU (10 mcg),  for bone health, however this amount is too tiny to be adequate to elevate vitamin D blood levels to an immune sufficient degree. It also makes no sense to advise the same tiny amount to ALL, irrespective of age, skin colour or bodyweight.

Finland has achieved successful food fortification in the past few years. Their vitamin D blood levels (65 nmol/l) are approximately double the average blood levels in Scotland (37 nmol/l). Finland’s mortality figures due to Covid-19 are very low.

Considering that vitamin D is perfectly safe, even “large” daily doses of 5000 – 10,000 IU (125 – 250 mcg), considering that it is cheap, why would our advisory bodies not give it the benefit of doubt, be practical in the face of a second winter wave of Covid-19, expected in a few months, and recommend for all, but at least to the high-risk groups, to take 2000 IU daily?

Some key references are listed below.

I hope you will consider this and allow an adequate vitamin D supplementation program to be implemented in Scotland or a food fortification program.

Many thanks,
Best wishes

Helga Rhein
Retired General Practitioner
Edinburgh EH7 4DR

Charoenngam N., Holick MF. Immunologic Effects of Vitamin D on Human Health and Disease. Nutrients 2020, 12, 2097; doi:10.3390/nu12072097

Grant WB, Lahore H, McDonnell SL, et al. Evidence that Vitamin D Supplementation Could Reduce Risk of Influenza and COVID-19 Infections and Deaths. Nutrients. 2020;12(4):988. Published 2020 Apr 2. doi:10.3390/nu12040988

Hanel A, Carlberg C. Vitamin D and evolution: Pharmacologic implications. Biochem Pharmacol. 2020;173:113595.

Vieth R. Best Pract Res Clin Endocrinol Metab. 2011 Aug;25(4):681-91.   Why the Minimum Desirable Serum 25-hydroxyvitamin D Level Should Be 75 nmol/L (30 Ng/Ml)

Davies G, Garami AR, Byers JC. Evidence Supports a Causal Role for Vitamin D Status in COVID-19 Outcomes. June 2020. medRxiv 2020.05.01.20087965; doi:

Brenner H, Holleczek B, Schoettker B. Vitamin D insufficiency and deficiency and mortality from respiratory diseases in a cohort of older adults: potential for limiting the death toll during and beyond the COVID-19 pandemic. medRxiv 2020.06.22.20137299; doi:

Food Standards Agency in Scotland. Vitamin D status of Scottish adults: Results from the 2010 & 2011 Scottish Health Surveys . Purdon G, Comrie F, Rutherford L, Marcinkiewicz A. September 2013.

Zgaga L, Theodoratou E, Farrington SM, et al. Diet, environmental factors, and lifestyle underlie the high prevalence of vitamin D deficiency in healthy adults in Scotland, and supplementation reduces the proportion that are severely deficient. J Nutr. 2011;141(8):1535-1542. doi:10.3945/jn.111.140012

Hyppönen E, Power C. Hypovitaminosis D in British adults at age 45 y: nationwide cohort study of dietary and lifestyle predictors. Am J Clin Nutr. 2007;85(3):860-868. doi:10.1093/ajcn/85.3.860

Rhein HM. Vitamin D deficiency is widespread in Scotland. BMJ 2008;336June28.

Raulio S, Erlund I, Männistö S, et al. Successful nutrition policy: improvement of vitamin D intake and status in Finnish adults over the last decade. European Journal of Public Health. 2017 Apr;27(2):268-273. DOI: 10.1093/eurpub/ckw154.

Pilz S, März W, Cashman KD, et al. Rationale and Plan for Vitamin D Food Fortification: A Review and Guidance Paper. Front Endocrinol (Lausanne). 2018;9:373. Published 2018 Jul 17. doi:10.3389/fendo.2018.00373

Manson JE, Bassuk SS, Buring JE; VITAL Research Group. Principal results of the VITamin D and OmegA-3 TriaL (VITAL) and updated meta-analyses of relevant vitamin D trials. J Steroid Biochem Mol Biol. 2019 Nov 13;198:105522.

Prof JoAnn Manson, Harvard, US:

Dr. David Grimes, ret consultant physician, Manchester, UK:

Helga Rhein in QNIS, June 2020: