Vitamin D, contrary to popular thought, IS NOT A VITAMIN. It is an inflammation-regulating steroid hormone involved in many of the body’s essential processes.1. Leaked NHS internal guidance, issued in June 2020, states that “evidence supports a causal role in Vitamin D status and Covid-19 outcomes”, and urges clinicians to “monitor, report and treat”.2
Meanwhile, a NICE rapid evidence review also published in June, states “there is no evidence to support taking vitamin D supplements to specifically prevent or treat COVID‑19.” However, it does re-enforce its September 2018 advice that at-risk groups should take a 10µg supplement all year round.3
Rewind to MARCH 2018: the ‘world’s biggest quango’ NHS England, released new guidance not to issue Vitamin D and many other commonly available over-the-counter (OTC) medicines on prescription, which was intended to save NHS costs by promoting patient self-care.4
Vulnerable elderly care home residents, many of whom lack mental capacity, are unable to obtain Vitamin D without a prescription, as Care and Quality Commission (CQC) regulations prevent tablets being given by care staff without GP Guidance..5
This logistical deadlock has NOT BEEN resolved, and Vitamin D deficiency has long BEEN KNOWN TO BE widespread in care homes.6 Over 19,000 care home residents in England have died with Covid-19, representing at least 36% of all Covid-19 fatalities in England and Wales.7, 8
Defining evidence: why the different guidelines?
Evidence is increasing that Vitamin D deficiency is CAUSALLY LINKED to BOTH likelihood of contracting covid-19, AND severity of infection.9
The NICE rapid evidence review,3 which states there is “no specific evidence” for Vitamin D in Covid-19, is heavily focused on the outcomes of the eight included studies, WITHOUT CORROBORATING THIS WITH the known physiological mechanism for how Vitamin D attenuates the inflammatory cascade in the lungs with coronaviruses.10 The physiology surely somewhat dispels the caution that NICE have that the correlation between low Vitamin D and severe covid-19 may be incidental, or weakened by potential ‘confounders’. Confounders are factors which account for, or mask, an association. However, the confounders that the NICE review3 claim weaken three of the included studies could may actually strengthen when causal inference is considered. These confounders mentioned by NICE for Covid-19 severity included obesity, high blood pressure and socio-economic status: these are all independently linked to low vitamin D status.11, 12, 13 COULD Vitamin D status, therefore, BE the common link? The physiological mechanism would support this. The NICE rapid evidence has excluded relevant data on counties affected by Covid-19 and their latitude, showing countries such as the UK, who are above the 30 ̊north latitude line, meaning there is not enough light for the skin to make Vitamin D all year round. Interestingly, in the UK, THERE IS NOT ENOUGH sunlight between October and March, 6 meaning deficiency would be at its peak in the population at the end of March.
In short, the leaked report, now a published study,2 is more comprehensive and credible than the NICE rapid evidence review, as it includes ALL the circumstantial as well as the forensic evidence.