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NCT Number: NCT04609423

Cod Liver Oil for Covid-19 Prevention Study

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.

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Key information

Conditions

COVID-19 Coronaviridae Infections Coronavirus Infections Infections Lung Diseases Nidovirales Infections Pneumonia Pneumonia, Viral RNA Virus Infections Respiratory Tract Diseases Respiratory Tract Infections Virus Diseases

Age range

18 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

Oslo University Hospital

Oslo, 0424, Norway

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

cod liver oil

Dietary Supplement

5 ml of cod liver oil as a source of 10 ug of vitamin D and 1.2 g of long-chained n-3 polyunsaturated fatty acids (DHA 0,6g and EPA 0,4g) per day for 6 months x 1 time/day together with the first meal of the day. 5ml of Cod liver oil also contains 250ug vitamin A and 10 mg vitamin E.

Other names: 10 ug of vitamin D and 1 g n-3 LCPUFA, Tran

Corn oil (placebo)

Dietary Supplement

5 ml of corn oil per day for 6 months x 1 time/day together with the first meal of the day

Primary outcomes

  1. Number of participants diagnosed with serious Covid-19

    Time frame: 6 months

    The number of participants with first time SARS-CoV-2 positive nasopharyngeal and or pharyngeal swabs (or any other sample used for detection of current disease) analyzed by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) nucleic acid amplification test or antigen tests used by accredited Norwegian microbiology laboratories in the period from one week after the start of cod liver oil/placebo taking to the end of this period together with any of the following:

    A) Self-reported dyspnea and fever concurrent (within four weeks) with the positive test OR B) hospitalization caused by Covid-19 concurrent (within four weeks) with the positive test OR C) death where the Covid-19 infection was wholly or partly responsible as judged by the death certificate (see endpoint in the protocol)

  2. Number of participants diagnosed with New Covid-19

    Time frame: 6 months

    The number of participants diagnosed with first time SARS-CoV-2 positive nasopharyngeal and or pharyngeal swabs (or any other sample used for detection of current disease) analyzed by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) nucleic acid amplification test or antigen tests used by accredited Norwegian microbiology laboratories from one week after the start of cod liver oil/placebo taking.

  3. Number of participants with negative SARS-CoV-2 test

    Time frame: 6 months

    Number of participants with an airway sample negative for SARS-CoV-2 (indicative of another airway infection).

    *Influenza virus (A and B), parainfluenzavirus (1,2,3), metapneumovirus, rhinovirus, coronavirus (non-SARS), Respiratory Syncytial virus, Haemophilus Influenzae, Moraxella Catharralis, Streptococcus Pneumonia, Beta-hemolytic streptococci, Mycoplasma pneumonia, Chlamydophila pneumonia, Enterovirus, Bordetella pertussis. The list can be expanded based on the analyses performed in Norwegian Microbiology laboratories.

  4. Number of participants with self-reported airway infection

    Time frame: 6 months

    The number of episodes with any two of the following symptoms: fever, cough, nasal congestion or sore throat

Secondary outcomes

  1. Number of participants hospitalized due to Covid-19

    Time frame: 6 months

    Number of participants hospitalized wholly or partly caused by Covid-19.

  2. Number of participants in Intensiv Care Unit (ICU) caused by Covid-19

    Time frame: 6 months

    Number of participants with ICU care wholly or partly caused by Covid-19.

  3. Number of participants with any admissions to hospital

    Time frame: 6 months

    Number of participants with any admissions to hospital based on the Norwegian Patient Registry data.

  4. Infection with each of the mentioned pathogens

    Time frame: 6 months

    An airway sample positive for a respiratory pathogen* (either PCR or culture) in the period from one week after the start of cod liver oil/placebo taking to the end of this period.

    *Influenza virus (A and B), parainfluenzavirus (1,2,3), metapneumovirus, rhinovirus, coronavirus (non-SARS), Respiratory Syncytial virus, Haemophilus Influenzae, Moraxella Catharralis, Streptococcus Pneumonia, Beta-hemolytic streptococci, Mycoplasma pneumonia, Chlamydophila pneumonia, Enterovirus, Bordetella pertussis. The list can be expanded based on the analyses performed in Norwegian Microbiology laboratories.

  5. Number of visits at GP for infections

    Time frame: 6 months

    Based on The Norwegian Reimbursement Database

  6. Number of visits at GP

    Time frame: 6 months

    Based on The Norwegian Reimbursement Database

Other outcomes

  1. Incidence of Cardiovascular disease

    Time frame: 6 months

    Based on self-reporting and Norwegian Registries

  2. Incidence of Cardiovascular disease

    Time frame: 30 months

    Based on self-reporting and Norwegian Registries

  3. Incidence of cardiovascular mortality

    Time frame: 6 months

    Based on self-reporting and Norwegian Registries

  4. Incidence of cardiovascular mortality

    Time frame: 30 months

    Based on self-reporting and Norwegian Registries

  5. Incidence of cancer

    Time frame: 6 months

    Based on self-reporting and Norwegian Registries

  6. Incidence of cancer

    Time frame: 30 months

    Based on self-reporting and Norwegian Registries

  7. Incidence of cancer mortality

    Time frame: 6 months

    Based on self-reporting and Norwegian Registries

  8. Incidence of cancer mortality

    Time frame: 30 months

    Based on self-reporting and Norwegian Registries

  9. All-cause mortality

    Time frame: 6 months

    Based on self-reporting and Norwegian Registries

  10. All-cause mortality

    Time frame: 30 months

    Based on self-reporting and Norwegian Registries

  11. Incidence of fracture of the hip or forearm

    Time frame: 6 months

    Based on self-reporting and Norwegian Registries

  12. Incidence of fracture of the hip or forearm

    Time frame: 30 months

    Based on self-reporting and Norwegian Registries

  13. Incident dementia

    Time frame: 6 months

    Based on self-reporting and Norwegian Registries

  14. Incident dementia

    Time frame: 30 months

    Based on self-reporting and Norwegian Registries

  15. Number of participants diagnosed with serious Covid-19

    Time frame: 12 months

    The number of participants with first time SARS-CoV-2 positive nasopharyngeal and or pharyngeal swabs (or any other sample used for detection of current disease) analyzed by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) nucleic acid amplification test or antigen tests used by accredited Norwegian microbiology laboratories in the period from one week after the start of cod liver oil/placebo taking to the end of this period together with any of the following:

    A) Self-reported dyspnea and fever concurrent (within four weeks) with the positive test OR B) hospitalization caused by Covid-19 concurrent (within four weeks) with the positive test OR C) death where the Covid-19 infection was wholly or partly responsible as judged by the death certificate (see endpoint in the protocol)

  16. Number of participants diagnosed with new Covid-19

    Time frame: 12 months

    The number of participants diagnosed with first time SARS-CoV-2 positive nasopharyngeal and or pharyngeal swabs (or any other sample used for detection of current disease) analyzed by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) nucleic acid amplification test or antigen tests used by accredited Norwegian microbiology laboratories from one week after the start of cod liver oil/placebo taking.

  17. Laboratory confirmed respiratory tract infection

    Time frame: 12 months

    An airway sample positive for a respiratory pathogen* (either PCR or culture).

    *Influenza virus (A and B), parainfluenzavirus (1,2,3), metapneumovirus, rhinovirus, coronavirus (non-SARS), Respiratory Syncytial virus, Haemophilus Influenzae, Moraxella Catharralis, Streptococcus Pneumonia, Beta-hemolytic streptococci, Mycoplasma pneumonia, Chlamydophila pneumonia, Enterovirus, Bordetella pertussis. The list can be expanded based on the analyses performed in Norwegian Microbiology laboratories.

  18. Self-reported airway infection

    Time frame: 12 months

    The number of episodes with any two of the following symptoms: fever, cough, nasal congestion or sore throat

  19. Number of participants with self-reported cod liver oil related adverse events

    Time frame: 12 months

    Number of participants with self-reported adverse events

  20. Number of participants with cod liver oil related adverse events

    Time frame: 12 months

    Number of participants hospitalized for major diseases or death in the cod liver oil versus placebo group in Norwegian registries

Sponsors and collaborators

Lead sponsor

Oslo University Hospital

Other

Collaborators

  • Norwegian Institute of Public Health
  • University of Oslo

Registry information

Official study 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

Important dates

Study start
2020
Primary completion
2021
Study completion
2021
First posted
Oct 30, 2020
Registry last updated
Apr 6, 2022

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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