No evidence that vitamin D is able to prevent or affect the severity of COVID-19 in individuals with European ancestry: a Mendelian randomisation study of open data
Compose Response

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
Author Information
First or given name, e.g. 'Peter'.
Your last, or family, name, e.g. 'MacMoody'.
Your email address, e.g.
Your role and/or occupation, e.g. 'Orthopedic Surgeon'.
Your organization or institution (if applicable), e.g. 'Royal Free Hospital'.
Statement of Competing Interests


  • Responses are moderated before posting and publication is at the absolute discretion of BMJ, however they are not peer-reviewed
  • Once published, you will not have the right to remove or edit your response. Removal or editing of responses is at BMJ's absolute discretion
  • If patients could recognise themselves, or anyone else could recognise a patient from your description, please obtain the patient's written consent to publication and send them to the editorial office before submitting your response [Patient consent forms]
  • By submitting this response you are agreeing to our full [Response terms and requirements]

Vertical Tabs

Other responses

Jump to comment:

  • Published on:
    Small differences = no effects

    The authors report data on genetically determined Vitamin D levels and their association with SARS-CoV-2 infection and severe COVID-19 courses. They conclude: "In conclusion, we found no evidence that vitamin D is protective against SARS-CoV-2 infection or COVID-19 severity. "

    The main problem of this analysis from GWAS data is, that the observed difference between Vitamin D-levels in quartile 1 (45,6 nmol/l = 18 ng/ml) and quartile 4 (54,0 nmol/l = 21,6 ng/ml) is so small, that no one would it expect to have an effect on the predefined endpoints.

    In order to achieve optimum immune responses, a Vitamin D-level of at least 75 nmol/l, preferably >100 nmol/l would be required.
    So, as much as this study seems to give an evidence-based conclusion, it is not helpful at all to answer important questions for clinicians:

    1) Does Vitamin D-supplementation to achieve OPTIMUM Vitamin D levels reduce the likelihood of SARS-CoV-2 infection?

    2) Does a high-dose vitamin D therapy (like 3x 40 000 IU in week 1) in early SARS-CoV-2 infection prevent severe courses of COVID-19, as it was suggested by the randomised intervention study by Castillo et al.

    From a clinician’s standpoint, to me it seems clear, that all people should be advised to treat a Vitamin D deficiency of < 75 nmol/l or 30 ng/ml, as there are virtually no risks of Vitamin D supplementation, and possibly many benefits in this Pandemic situation, especially in the immunoc...

    Show More
    Conflict of Interest:
    None declared.