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Opinion or narrative review

Review of vitamin D and COVID-19: low levels linked to worse illness, trials inconsistent

Bandeira and colleagues · Reviews in endocrine & metabolic disorders · 2022

Original title: Clinical aspects of SARS-CoV-2 infection and vitamin D : COVID-19 and the endocrine system: special issue for reviews in endocrine and metabolic disorders (Felipe Casaneuva, Editor in Chief) A. Giustina and JP Bilezikian, Guest Editors.

Under review. A person has not yet checked this summary against the paper. It is written from the PubMed abstract. Until a person checks it, search engines are asked not to list this page.

What the study found

Mixed

Most observational and cohort studies link low vitamin D to worse COVID-19. The few trials give inconsistent results. The authors await larger randomized trials.

The study at a glance

Type of study
Opinion or narrative review
Who or what was studied
People with COVID-19
What was tested
Review of studies linking vitamin D status to COVID-19
Who has a stake
Company stake
One author leads a vitamin D deficiency study in Brazil sponsored by Mantecorp, a drug company.
Journal
Reviews in endocrine & metabolic disorders, 2022
Source
PubMed record 34559361. This page is based on the abstract only.

How much this study counts

  • –An opinion or narrative review: no new data, and no set method for choosing which studies to discuss.
  • –Company stake: One author leads a vitamin D deficiency study in Brazil sponsored by Mantecorp, a drug company.
  • •Summarized from the PubMed abstract only. The full paper may hold details the abstract leaves out.

✓ Strength– Limit• Note

These points come from fixed rules about the type of study, its size and length, what it measured, and who has a stake. Every study on Digestery gets the same rules.

Where this study sits

This paper is not on the ladder. It is a opinion or narrative review, and reviews and opinion pieces discuss studies that are already counted on the steps below.

↑ Stronger evidence

  1. Trials in people: colds, flu and chest infections

    10

    2 benefit, 8 no difference

  2. Trials in people: other measures

    5

    1 benefit, 1 mixed, 2 no difference, 1 harm

  3. Trials in people: lab tests or safety

    1

    1 no difference

  4. Population studies

    1

    1 no difference

  5. Blood levels and genes

    4

    3 benefit, 1 no difference

↓ Weaker evidence

  • Points to benefit
  • Mixed
  • No difference
  • No direction
  • Points to harm

How it fits with the other research

The short answer to “Does vitamin D prevent colds and infections?”

Not clearly; any effect looks small.

Confidence: low. Based on 33 on-topic papers.

Read the full answer
  • Open item for a person: Bandeira 2022: stake rests on Mantecorp sponsoring a vitamin D study; the abstract does not say Mantecorp sells vitamin D.

Other opinion on this question

See all 33 studies on this question

How this page was made

Label

First read of the abstract
Claude Sonnet
Independent second read
Claude Haiku
Differences settled
The two reads agreed on every checked field. Claude Opus 5.5.
Headline
Claude Sonnet, from the checked study record. A script checked its numbers and wording.
Numbers
Checked against the abstract by a script
“How much this study counts”
Fixed rules, the same for every study
Source check by a person
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