Clinical trial NCT04609423: Cod Liver Oil for Covid-19 Prevention Study
Official title: A Randomized, Parallel-group Treatment, Quadruple Masked, Two-arm Study, to Assess the Effectiveness of Cod Liver Oil Compared to Placebo in the Prevention of Covid-19 and Airway Infections in Healthy Adults
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Covid-19
Respiratory Tract Infections
Keywords: Cod liver oil
Vitamin D
n-3 LCPUFAs
SARS-CoV virus
Lead sponsor: Oslo University Hospital
Sponsor class: OTHER
Collaborators: name: University of Oslo
name: Norwegian Institute of Public Health
First posted: 2020-10-30
Enrollment: 47210
Sex: ALL
Minimum age (years): 18
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: A parallel-group treatment, two-arm study where participants are randomly assigned to cod liver oil or placebo (corn oil) in a 1:1 ratio
Primary purpose: PREVENTION

Brief summary: A randomized, parallel-group treatment, quadruple masked, two-arm study to assess the effectiveness of cod liver oil compared to placebo in the prevention of Covid-19 and airway infections in healthy adults.

In this study, the investigators will investigate whether daily cod liver oil can prevent Covid-19 infections and reduce the severity of such infections. The investigators will also examine whether cod liver oil prevents other airway infections in healthy adults.

Detailed description: Preliminary evidence from literature and an ongoing study in the investigators' lab suggests that cod liver oil may prevent Covid-19 and complications of Covid-19. In the present study, the investigators will examine whether this is actually the case by randomizing volunteers to take cod liver oil or placebo (corn oil) during the winter months of 2020-2021. The investigators also aim to explore whether cod liver oil can prevent other respiratory tract infections, as well as explore and confirm already known health effects and possible new health effects, in particular rare adverse events associated with cod liver oil use.

Cod liver oil is a traditional source of vitamin A, D, and E and omega-3 fatty acids and the dose administered in the study will contain 250 ug vitamin A, 10 ug vitamin D, 10 mg vitamin E, and 1,2 g omega-3 fatty acids.

Eligibility criteria: Inclusion Criteria:

* Any person \>18 years with a Norwegian Personal Identity Number

Exclusion Criteria:

* History of renal failure or dialysis, hypercalcemia, severe liver disease (cirrhosis), sarcoidosis or other granulomatous diseases (Wegener)
* Allergy to fish or corn oil.
* Pregnancy or planned pregnancy before summer 2021
* Vegan diet
* Age \>75 years old at inclusion based on the Norwegian Personal Identity Number
* Difficulty in swallowing cod liver oil or other oils
* Previous Covid-19 disease
* For Caucasians only: Use of any supplement containing more than trace amounts of vitamin D or omega-3 fatty acids at inclusion (Vitamin D levels in non-Caucasians living in Norway are frequently low even among those self-reporting using dietary supplements). This criterion will be relaxed if too few participants volunteer for the study and only Caucasians that use cod liver oil or an equivalent dietary supplement (with omega 3 and vitamin D) more than 5-7 times per week will be excluded.

Primary outcomes:
measure: Number of participants diagnosed with serious Covid-19
timeFrame: 6 months
measure: Number of participants diagnosed with New Covid-19
timeFrame: 6 months
measure: Number of participants with negative SARS-CoV-2 test
timeFrame: 6 months
measure: Number of participants with self-reported airway infection
timeFrame: 6 months
Secondary outcomes:
measure: Number of participants hospitalized due to Covid-19
timeFrame: 6 months
measure: Number of participants in Intensiv Care Unit (ICU) caused by Covid-19
timeFrame: 6 months
measure: Number of participants with any admissions to hospital
timeFrame: 6 months
measure: Infection with each of the mentioned pathogens
timeFrame: 6 months
measure: Number of visits at GP for infections
timeFrame: 6 months
measure: Number of visits at GP
timeFrame: 6 months
Other outcomes:
measure: Incidence of Cardiovascular disease
timeFrame: 6 months
measure: Incidence of Cardiovascular disease
timeFrame: 30 months
measure: Incidence of cardiovascular mortality
timeFrame: 6 months
measure: Incidence of cardiovascular mortality
timeFrame: 30 months
measure: Incidence of cancer
timeFrame: 6 months
measure: Incidence of cancer
timeFrame: 30 months
measure: Incidence of cancer mortality
timeFrame: 6 months
measure: Incidence of cancer mortality
timeFrame: 30 months
measure: All-cause mortality
timeFrame: 6 months
measure: All-cause mortality
timeFrame: 30 months
measure: Incidence of fracture of the hip or forearm
timeFrame: 6 months
measure: Incidence of fracture of the hip or forearm
timeFrame: 30 months
measure: Incident dementia
timeFrame: 6 months
measure: Incident dementia
timeFrame: 30 months
measure: Number of participants diagnosed with serious Covid-19
timeFrame: 12 months
measure: Number of participants diagnosed with new Covid-19
timeFrame: 12 months
measure: Laboratory confirmed respiratory tract infection
timeFrame: 12 months
measure: Self-reported airway infection
timeFrame: 12 months
measure: Number of participants with self-reported cod liver oil related adverse events
timeFrame: 12 months
measure: Number of participants with cod liver oil related adverse events
timeFrame: 12 months
Locations:
city: Oslo
country: Norway
facility: Oslo University Hospital
Study officials:
affiliation: Oslo University Hospital
name: Arne Søraas, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Brunvoll SH, Nygaard AB, Ellingjord-Dale M, Holland P, Istre MS, Kalleberg KT, Soraas CL, Holven KB, Ulven SM, Hjartaker A, Haider T, Lund-Johansen F, Dahl JA, Meyer HE, Soraas A. Prevention of covid-19 and other acute respiratory infections with cod liver oil supplementation, a low dose vitamin D supplement: quadruple blinded, randomised placebo controlled trial. BMJ. 2022 Sep 7;378:e071245. doi: 10.1136/bmj-2022-071245.