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Cod liver oil

Cod liver oil suppliers and sourcing guide

Cod liver oil is pressed or rendered from the livers of cod and related fish of the family Gadidae, then refined, winterized and deodorized. Unlike body fish oil, it naturally contains vitamins A and D as well as EPA and DHA, and those vitamin levels vary by catch. Brands buy it as a bulk liquid for bottled oils and softgels, often with natural or added flavors.

Also known as
Lecoris aselli oleum · Gadus morhua liver oil · Oleum jecoris aselli
Facts checked
November 2026

Forms and grades of cod liver oil

Suppliers sell different products under the same name. Specify the one you need.

  • Refined natural

    Refined cod liver oil sold with its natural vitamin A and D content stated as a range.

  • Vitamin-standardized

    Oil adjusted with added vitamin A and D to hit a fixed level per gram or per serving.

  • Flavored liquid

    Ready-to-bottle oil with lemon, orange or other flavors and added tocopherols.

  • Softgel grade

    Oil supplied for encapsulation, sometimes blended with fish oil to raise EPA and DHA.

What to check on the COA

Compare each result with your own specification when the lot arrives.

Vitamins A and D
Vitamin A and vitamin D3 by HPLC or LC-MS/MS; needed for label claims and to stay within maximum intakes.
EPA and DHA
Fatty acid profile by GC as methyl esters.
Peroxide, anisidine and TOTOX
Peroxide value (AOCS Cd 8b-90 or a pharmacopeial method) for primary oxidation and p-anisidine value for secondary oxidation, combined as TOTOX (2 x PV + AV).
Dioxins, PCBs and metals
Dioxins, furans and dioxin-like PCBs by GC-HRMS, plus lead, cadmium, mercury and arsenic by ICP-MS; these are the standard contaminant panel for marine oils.
Identity and appearance
Fatty acid profile and a cold test or clarity check to confirm the oil has been winterized.

Storage, lots and expiry

Storage and shelf life

Store sealed, away from light and heat, with a nitrogen headspace for bulk containers; refrigerate after opening. Vitamin A and D degrade along with the oil, so storage temperature affects both. Shelf life is set by the supplier specification, with oxidation values and vitamin assays retested on aged stock.

Lots and expiry dates

Natural vitamin A and D levels vary noticeably from lot to lot, so record the assayed values and recalculate label amounts when lots change. Rotate first-expiry, first-out.

Regulatory status

Facts from regulators and standards bodies, each linked to its source.

This is general information, not regulatory advice. Status differs by country and by how the ingredient is used, so check the rules for your product and market.

Cod liver oil suppliers

Manufacturers and distributors whose own websites say they sell it.

  • Bioriginal

    Manufacturer · Saskatoon, Canada

    Canadian supplier of plant and marine oils, coconut and MCT oils, seeds and proteins in bulk and finished formats for food, supplement and pet nutrition brands.

Suppliers are in alphabetical order and none pays to appear. Each claim is checked against the supplier’s own website on the date shown. Ask for the specification sheet and a recent COA before you order, and confirm details with the supplier.

Frequently asked questions

What forms of cod liver oil can brands buy?

Common forms include refined natural, vitamin-standardized, flavored liquid and softgel grade. Ask each supplier for the specification sheet of the exact grade they quote.

What should the COA for cod liver oil include?

Expect vitamins A and D, ePA and DHA, peroxide, anisidine and TOTOX, dioxins, PCBs and metals and identity and appearance, each with its method, specification and result for that lot.

How should cod liver oil be stored?

Store sealed, away from light and heat, with a nitrogen headspace for bulk containers; refrigerate after opening. Vitamin A and D degrade along with the oil, so storage temperature affects both. Shelf life is set by the supplier specification, with oxidation values and vitamin assays retested on aged stock.

What is the regulatory status of cod liver oil?

Health Canada's cod liver oil monograph lists the liver of fish of the family Gadidae as the source and sets a maximum peroxide value of 5 mEq/kg. 21 CFR 347.10 lists cod liver oil, at 5 to 13.56 percent, as an active ingredient for OTC skin protectant drug products.

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