Cod Liver Oil for Covid-19 Prevention Study

University of Oslo (UIO)

Status and phase: Completed; Phase 4

Conditions: Covid-19; Respiratory Tract Infections

Treatments: Dietary Supplement: Corn oil (placebo); Dietary Supplement: Cod liver oil

Study type: Interventional

Funder types: Other

Identifiers

NCT04609423

REK-172796

Details and patient eligibility

About

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.

Full 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.

Enrollment: 47,210 patients

Sex: All

Ages: 18 to 75 years old

Volunteers: Accepts Healthy Volunteers

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.

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

---

47,210 participants in 2 patient groups, including a placebo group

Cod liver oil

Experimental group

Description:

supplementation for 6 months

Treatment:

Dietary Supplement: Cod liver oil

Corn oil (placebo)

Placebo Comparator group

Description:

supplementation for 6 months

Treatment:

Dietary Supplement: Corn oil (placebo)