What each ingredient and food mentioned on this page is, what it is traditionally used for, and what the cited research says. This page is part of a paid advertisement; see the disclaimers below.
The two long-chain omega-3 fats of oily fish (salmon, sardines, anchovies, mackerel, herring). DHA is a building block of nerve-cell membranes; EPA is a precursor of signaling molecules. Supplements come as fish oil, krill oil, algal oil or, in RELEVATE, herring roe phospholipids.
Traditional and everyday use. Fish has been eaten for brain and heart for as long as there have been fishermen; fish-oil supplements date from the 1980s.
What the research says. The randomized trials in healthy older adults are mostly null: a 2012 Cochrane review of three trials in 3,536 people over 60 found no difference from placebo on mental-status scores or on word learning, digit span and verbal fluency;[1] an 18-month trial of 390 adults aged 65 to 90 taking 2.3 g a day of DHA-rich fish oil found no benefit and a small negative effect on psychomotor speed;[2] and the three-year DO-HEALTH trial found no effect of 1 g a day on a cognitive screening score.[3] A 2015 meta-analysis did find that DHA, alone or with EPA, improved episodic memory in adults with mild memory complaints, and that doses above 1 g a day helped episodic memory regardless of baseline.[4] One 24-month trial of 60 adults over 65 combining 1 g of fish oil with carotenoids and vitamin E found fewer working-memory errors.[5] A 2018 review of 51 trials concluded the question is still open.[6]
Amount per serving in Carlson Wild Norwegian Cod Liver Oil. 1,100 mg (per 5 mL teaspoon)
Good to know. Fishy burps and loose stools are the common complaints. Doses above about 3 g a day can affect bleeding: ask a pharmacist if you take blood thinners or have an operation planned. Fish allergy excludes fish-derived products.
The 'sunshine vitamin': the skin makes it from sunlight, and it is added to milk and found in fatty fish and egg yolk. It regulates calcium and bone. Many older adults in northern latitudes have low blood levels in winter.
Traditional and everyday use. No traditional use; identified in the 1920s.
What the research says. In the three-year DO-HEALTH trial of 2,157 adults aged 70 and older, 2,000 IU a day of vitamin D3 produced no statistically significant benefit on a cognitive screening score, alone or combined with omega-3s and exercise.[3] Correcting a real deficiency is a matter for a blood test and a doctor, not for a memory page.
Amount per serving in Carlson Wild Norwegian Cod Liver Oil. 10 mcg (400 IU) (50% DV)
Good to know. Safe at label doses; the tolerable upper level for adults is 100 mcg (4,000 IU) a day. Too much over time raises blood calcium.
A fat-soluble vitamin that the body uses for night vision, immune function and skin. It comes preformed from animal sources — liver, fish liver oils, eggs, dairy — or as carotenoids from orange and leafy plants. Cod liver oil carries it naturally, which is why the old bottles are remembered as much for the taste as for anything else.
Traditional and everyday use. Cod liver oil was given to children in northern Europe and North America for generations, long before vitamins were named; the vitamin A in it is part of what the fish's liver stores.
What the research says. We cite no trial for vitamin A on this page. The Daily Value used on US labels is 900 mcg RAE for adults, so a label can be read as a share of it.
Amount per serving in Carlson Wild Norwegian Cod Liver Oil. 255 mcg RAE (850 IU) (28% DV)
Good to know. The adult tolerable upper level for preformed vitamin A is 3,000 mcg RAE (10,000 IU) a day; the teaspoon here is well under a third of it. Larger amounts over time can be harmful, and vitamin A interacts with several medicines — if you take anything daily, or are pregnant or nursing, show the label to your doctor or pharmacist.
A fat-soluble vitamin that works as an antioxidant in cell membranes; in a liquid supplement it also helps keep the oils from spoiling. Labels print it as d-alpha tocopherol, the natural form, sometimes with an acetate group attached for stability. Nuts, seeds, vegetable oils, spinach and avocado are the usual food sources.
What the research says. In small amounts it is part of how the liquid stays fresh. We make no claim for the amount on the label.
Amount per serving in Carlson Wild Norwegian Cod Liver Oil. 6.7 mg (45% DV)
Good to know. At high supplemental doses vitamin E can interfere with vitamin K and raise the risk of bleeding, which matters if you take anything daily that affects clotting; the amount here is modest. The upper limit for adults is 1,000 mg a day. If you take anything daily, show the label to your pharmacist first.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This information does not constitute medical advice and it should not be relied upon as such. This product is not a substitute for medication or other treatment prescribed by a physician or health care provider. Consult your doctor before starting any dietary supplement.