Wednesday 16 September 2020

Covid-19 and Vitamin D. More evidence of benefit: observational studies from Italy, USA, Israel, Iran, Germany.

My previous Blog post was on the subject of "Covid-19 and Vitamin D: randomised controlled trial from Spain". This was the first RCT of vitamin D in Covid-19 and it had been demanded by commentators who were playing down the well-researched role of vitamin D in defensive immunity. 

To repeat: of 26 control patients admitted to hospital with Covid-19 pneumonia (on X-ray or CT scan), 13 (50%) needed admission to intensive care and 2 (8%) died. Of the 50 similar patients randomly allocated to receive vitamin D (initially 20,000 units and 10,000 units on days 3 and 7) only 1 (2%) required admission to intensive care and none died.

What could possibly be more clear and compelling than this? 2% versus 50% requiring intensive care. It is just what we might need in the UK in case of a "winter surge", especially with a vaccine being of unknown impact. Rather than awaiting admission to hospital with Covid-19 pneumonia, the vitamin D could be administered in advance.

But the report from Spain has been completely ignored by the government and its medical-scientific advisors, by the radio and TV news, by the press, and so far even by the medical  and scientific journals. Not even a hint of recognition and enthusiasm.

Why is this? Could it be directed by the Bill Gates and Big Pharma funded WHO? After all vaccines are to be given to the world population. There is big money at stake, and a cheap and safe competitor such as vitamin D is not to be encouraged.

But the evidence for vitamin D being of great benefit in protection of humankind against Covid-19 and future unknown viruses continues to accumulate. Can it be ignored indefinitely? As I have mentioned before, how many of our medical-scientific-political leaders are taking vitamin D? Dr Fauci in the USA has admitted in interview that he has been taking vitamin D. 

Here are more studies, careful observations that make a much stronger case for the role of vitamin D in defensive immunity against Covid-19. 

Observations from Bari, Italy

Bari Polyclinic

Published on August 8th and subsequently viewed 131k times, was a study from the ICU of the Hospital Polyclinic of Bari, in southern Italy. It investigated the vitamin D status of patients with Covid-19 and applied this to the clinical outlook for these patients.

It took as 30ng/ml (75nmol/L) vitamin D as the level above which it is considered to be ideal and below which is deficient, or certainly below ideal. This is reasonable based on previous studies. 

Considering the sunny weather in Bari (compared for example to NW UK where I live) it is perhaps surprising that 81% of those tested had a blood level of vitamin D below 30ng/ml. However this is not an uncommon finding. Residents of Mediterranean holiday resorts usually avoid the strong sun whenever possible. 

The subjects were divided into four groups on the basis of the blood level of vitamin D. The distribution can be seen in Figure1.

The endpoint of the study was death at 10 days, and for the purpose of analysis there were just two groupings:

Vitamin D level <10 ng/ml 50% died

Vitamin D level >=10 ng/ml 5% died

This finding is dramatic and cannot be ignored, or should not be ignored. People with blood vitamin D level <10ng/ml should be identified and treated, as is done for people with high blood pressure or high blood glucose. It is a very important health indicator. 

The result of this study conforms to previous studies. It is unfortunate that the death risk was not recorded separately for all four vitamin D groups. This might have shown a gradient of risk related to vitamin D status, and this would have been a powerful finding.  

Observations from Chicago, USA

University of Chicago Medical Centre

Researchers at the University of Chicago Medicine investigated 489 out of 4314 patients who had tested positive for Covid-19. The use of the term "patients" implies that these "patients" were ill with respiratory infection rather than being asymptomatic individuals who merely had a positive test. They were among a larger group who had  blood levels of vitamin D tested during the previous year.

Patients deficient in vitamin D during the previous year had a risk of Covid-19 1.77 times greater than those who were sufficient. 

Risk of Covid-19:

Vitamin D deficient = 21.6%

Vitamin D sufficient = 12.2%

This study adds to knowledge that a low level of vitamin D increases the risk of Covid-19 clinical infection (as opposed to just positive testing). This study did not include the risk of death.

Observations from Israel

A study was undertaken of the 4.6 million members of the Clalit Health Services, using electronic health records. 

Between the years 2010 and 2019, 1,359, 339 (>30% of the members) had a vitamin D measurement performed and the results were analysed. 

Israel has its general population and within it two special ethnic groups, the Arab people and the ultra-orthodox Jews both of which exhibit modest dress habit with little skin exposure, especially Arab women. Despite the very sunny climate of Israel and its long summer, it is perhaps surprising that vitamin D deficiency is very common. In particular 59.1% of Arab women had seriously low blood levels of vitamin D, less than 12 ng/ml, or 30 nmol/L. The full results are show in the Figure below. 

This is perhaps a complex "rainbow" image, but the red columns represent seriously low levels of vitamin D (<12ng/ml, 30nmol/L) and the blue columns represent very good levels (>30ng/ml, 75nmol/L), more common in the general population than in the ethnic groups.

The same medical records were examined for evidence of Covid-19 infection, and comparisons made each with ten matched controls. The Covid-19 infection rates can be seen in Figure below. It was below 1% in the general population, but above 1% in the Arab groups 1.12 in males, 1.64 in females) and much higher in the ultra-orthodox (3.37 in males, 2,69 in females). 

There was strong correlation between severe vitamin D deficiency and Covid-19 infection. The particularly high Covid-19 incidence in ultra-orthodox men was put down to the dress code of a wide-brimmed hat together with a traditional heavy beard, these minimising sun exposure. This does not entirely correlate with the blood vitamin D levels, but there is another factor.

We can also see in the Figure below that the incidence of Covid-19 infection was lowest in those who had the lowest blood levels of vitamin D. 14.3% of the sample of 18,361 with vitamin D greater than 30ng/ml (75nmol/L) had Covid-19 infection, whereas those with lower vitamin D levels (less than 30ng/ml) had twice the incidence of infection, 28.6%. 

The blood levels of vitamin D had been undertaken as part of normal clinical practice rather than an epidemiological study. Because of this most of those found to have vitamin D deficiency were given a vitamin D supplement, usually as drops. It was observed that prescription of vitamin D was associated with a reduced Covid-19 infection risk.

Here have seen yet another study indicating a protective role of vitamin D in protection against Covid-19. An ideal blood level of vitamin D (>30ng/ml) reduced by half the risk of Covid-19 infection.

In this study the low vitamin D level predated the infection. The low vitamin D level was definitely not the result of Covid-19 infection.

Observations from Iran

Virus Res. 2020 Aug 28;198148. doi: 10.1016/j.virusres.2020.198148

The study was of 65 male and 58 adult patients admitted to the Behpooyhan Clinic, Tehran, on account of proven Covid-19 pneumonia. They were compared to 63 control Covid-19 patients of similar age.

The average (mean) blood vitamin D level in the Covid-19 patients was 19.25 ng/ml (50 nmol/L), and in the controls it was 30.17 (70). In those who died it was particularly low  at (20nmol/L).

The results were as in several other studies, supporting the strong evidence that vitamin D deficiency is a major factor in clinical Covid-19 infection and death from it.

Observations from Heidelberg, Germany

Medical University Hospital, Heidelberg

A study from the Medical University Hospital, Heidelberg was published on September 1st 2020. It was a prospective study of 185 patient with Covid-19 and a retrospective study of their vitamin D status and its association with outcome.

Of the 185 patients, 92 were managed on home treatment and 93 required admission to hospital so as to maintain oxygenation. Of the 93 admitted, 28 (60% of those admitted, 29.5% of total) required invasive ventilation, and 16 ( 15% of those admitted, 8% of total) died.  All patients had required standard treatment including azithromycin, hydroxychloroquine, prednisolone (steroid). 

Blood samples from all patients were frozen and analysed for vitamin D at the end of the study. 

The average (mean) blood level of vitamin D of the 185 subjects was 16.6ng/ml (41.5nmol/L). Vitamin D deficiency was defined in this study as less than 12ng/ml (30nmol/L). This was observed in 41 of the 185 patients (22%). It is remarkable that this severe deficiency of vitamin D was so common in a prosperous German city, at least in those who were sick with Covid-19, but no doubt less common in the general healthy population that were not included in this study..

The distribution is shown in the Figure (the vertical black line indicates 30ng/ml, above which blood levels of vitamin D are ideal. 

Observations during the Covid-19 pandemic in particular has confirmed previous experience that although a blood vitamin D level of 20ng/ml (50nmol/L) is adequate to avoid rickets and osteomalacia, a minimum level of 30ng/ml (75nmol/L) is necessary for the escalation of defensive immunity at a time of serious infection. Approximately 160 of the 185 patients (86%) were deficient in vitamin D by this definition.

In this study the risk of death was expressed as the "Hazard Ratio", HR, excess risk if those with vitamin D deficiency related to those with ideal blood levels of vitamin D. 

Of the 22% with serious vitamin D deficiency (<12ng/ml):

HR for invasive ventilation  =  6.12

HR for death                         = 14.73

This study took place during  period of three months. The bloods could have been analysed for vitamin D earlier. This might have revealed  similar hazard ratios and on ethical grounds the observational study could have been halted. It could have been converted into a randomised controlled trial, but it would have been much easier to convert it into a longitudinal trial. This would have involved commencing intervention with vitamin D supplements after six weeks, and then comparing outcome before and after this intervention. It would have added to the study and it would probably have resulted in reduced need for invasive ventilation and fewer deaths.


  • The study from Bari demonstrated a 10-fold increase in risk of death from Covid-19 in those with serious vitamin D deficiency.
  • The study from Chicago demonstrated a double risk of Covid-19 infection in those deficient of vitamin D.
  • The study from Israel demonstrated a double risk of Covid-19 infection in those deficient of vitamin D, and much increased risk of death.
  • The study from Iran demonstrated a high risk of death from Covid-19  in those deficient of vitamin D.
  • The study from Heidelberg demonstrated an almost 15-fold increase in risk of death from Covid-19 in those with serious vitamin D deficiency. 

How is it that these studied have been ignored by governments and the press? How many more people must die as a result of official inaction? Why are our officials asleep at the wheel? When will inertia be replaced by action?



  1. David,
    Thanks so much. You are to be congratulated on your clear and lucid analysis of these trials and studies and all those that have gone before. It is outrageous and unbelievably frustrating that those claiming to represent the medical profession in the UK and the world generally, continue to ignore the obvious truth to the point of criminal professional neglect.

    So what is to be done to shake them out of their slumber? We surely need to urgently form a responsible professional pressure group of medical and other scientists.

    Two thoughts spring to mind...

    !) Point out that ‘COVID’ is an occult acronym for Cause Zero VItamin D. Maybe someone with an artistic bent could design this into a logo

    2) One possible title for the pressure group would be
    Scientists Against Pandemic Subversion (SAPPS)

    or Scientists and Medics Against Pandemic Subversion (SAMAPS)

    I am sure someone can think of better ones. But together we stand a chance, while divided we fall

  2. Of course the first or second P in SAPPS stands for Parma

  3. If Remdesivir showed these results it would be hailed as a 'game changer'.

    It is, in fact, a game changer, made all the more difficult by social media channels not wanting to highlight the news about the role of Vitamin D.

    We are going now into the winter where barring eating a lot of oily fish we are reliant on supplements to raise levels of vitamin D.