The study, highlighted by Conservative ex-cabinet member David Davis, suggested patients hospitalised with COVID-19 that received calcifediol treatment at the time of hospitalisation significantly reduced ICU admission and mortality.
The Conservative MP took to Twitter, informing his 170.1K followers that it was a, “very important study on vitamin D and Covid-19”.
“Its findings are incredibly clear,” he continues. “An 80% reduction in need for ICU and a 60% reduction in deaths, simply by giving a very cheap and very safe therapy - calcifediol, or activated vitamin D.
“The findings of this large and well conducted study should result in this therapy being administered to every COVID-19 patient in every hospital in the temperate latitudes.
Possible methodology issues
The comments came in for some heavy criticism by prominent scientists active in COVID-19 research, who had issues with the methodology, protocol procedures and even registration status of the trial, details of which appears in the journal SSRN.
Adrian Martineau, Clinical Professor of Respiratory Infection and Immunity, Queen Mary University of London said of the study, “some dramatic positive findings are presented, but important methodological details are missing.
“First, it is not clear whether or how the randomisation was done. The abstract mentions randomisation – but Methods do not describe how it was done – they simply state that ‘551 received calcifediol at admission to the hospital and 379 were not treated (control group).”
Professor Martineau, the Chief Investigator of the CORONAVIT trial – the UK’s national clinical trial of vitamin D supplementation addressing COVID-19, suggested randomisation issues with the trial with intervention and control groups not evenly balanced in size.
In addition, the professor also pointed to an uneven balance of these groups in regard to key baseline characteristics such as sex composition and baseline vitamin D levels.
“Second, 50 patients in the control group received the vitamin D metabolite calcifediol during ICU admission ‘at the discretion of the treating physicians and outside the original protocol,” he stressed.
“This represents a pretty significant breach of the protocol and calls into question the validity of the study’s results,”
“Third, I could not find the registration for the trial. It is standard practice to register clinical trials before they start recruiting, and it’s not clear whether this was done.
“Overall, more methodological detail is needed before the claims of treatment benefit can be substantiated.”
Non-peer reviewed study
Professor Martineau’s comments about the unpublished non-peer reviewed study were also echoed by Naveed Sattar, Professor of Metabolic Medicine at University of Glasgow.
“This is interesting but a huge dose of scepticism in the top line results is warranted as this is NOT a randomised controlled trial with no information on process of randomisation, and lack of placebo,” he said. “It also does not appear to be registered as a trial.
“Also, baseline differences in more females in the vitamin D3 (calcifediol) group plus higher vitamin D levels, could easily confound the results.
“There is also no reason to relate vitamin D levels to outcomes as that is observational and tells us nothing new as we know vitamin D levels are lower in sicker patients – we have known this for decades in many conditions.
“In short, this is not a useful study as it falls well short of a well conducted randomised trial. Whilst many wish to believe Vitamin D is the cure to covid-19 or an exciting treatment, this ‘trial’ cannot allow any such inference. We must await robust randomised trials to form appropriate conclusions.”
Look to Andalusia
Davis’ comments come just days after he urged UK Prime Minister Boris Johnson to follow the example of Andalusia and distribute vitamin D supplements to populations most at risk of contracting COVID-19.
In this month’s Prime Minister Questions (PMQs), Davis pointed to the Spanish region’s distribution of calcifediol to care home residents in November.
Latest figures from Andalusia highlight a drop in deaths per million from COVID-19 from 187 in November to just 11 at the start of January - an 82% drop.
“After giving out activated vitamin D to care home residents and some GP patients that death rate almost halved whilst ours was doubled,” Davis said. “Can he ask his advisors to look urgently again at the very latest Spanish research around this cheap, safe and apparently effective treatment.”
In response, the Prime Minister said the government would continue to monitor all the evidence about the efficacy of vitamin D and the mentioned treatments.
“I am well aware of it; indeed, we have discussed it before personally,” he added. “I will keep him updated on the review that is taking place.”