Cod Liver Oil — Tried and True

Cod liver oil (CLO) is a traditional nutritional supplement with diverse benefits. It is an excellent source of the anti-inflammatory, cardioprotective omega-3 fatty acids EPA and DHA, contains significant levels of naturally occurring vitamins A and D, and may be appropriately dosed for use by people of all ages.

During the first half of the 20th century, cod liver oil was recommended widely for the prevention of childhood rickets, a bone disease caused by vitamin D deficiency. In England, a free “welfare foods” program providing meat, milk, eggs and cod liver oil to pregnant women, nursing mothers, and children under five years of age was credited with abolishing rickets by the early 1940s.

The ability of cod liver oil to promote skeletal health is generally attributed to its vitamin D content but the vitamin A in CLO also plays a prominent role in maintaining optimal bone status. An in vivo study found that cod liver oil but not vitamin A alone restored bone thickness in vitamin A deficient animals.

Outside of bone health, vitamins A and D work together in numerous physiological processes, notably healthy immune system function. Research from as far back as 1934 notes the ability of vitamins A and D to assist in preventing the common cold and influenza.

In addition, vitamin D contributes to healthy muscle and metabolic function. Vitamin A is required for visual and reproductive health, healthy skin structure/function, and mucous membrane health, including respiratory health, an area where cod liver oil may offer significant support.

A cluster-randomized Columbia University study conducted from winter through early spring in New York City found that pediatric patients with upper respiratory illnesses required approximately 40%-60% fewer visits when they took a daily teaspoon of purified, lemon-flavored cod liver oil plus a multivitamin/mineral supplement. Additional research by this group suggests CLO may help to decrease the incidence or duration of ear and sinus infections in children. However, it may not be appropriate for those with asthma.

Recently in adults, the cardiovascular benefits of cod liver oil have been studied. A 2021 paper describes an intervention where 600 patients with elevated cholesterol levels were randomized into two groups. All patients were put on a daily 10 mg of a statin drug, but one group also took a 415 mg capsule of cod liver oil each day, while the other group took a placebo. After 30 days, a significant reduction in all lipid values was observed in both groups, but the reductions in total and LDL cholesterol were relatively more significant in the CLO group.

Today’s cod liver oil is cost-effective and highly palatable thanks to advanced purification processes that eliminate fishiness. Moss Nutrition offers superior quality Icelandic Cod Liver Oil in both liquid and softgel formats to address individual needs and preferences.

By Diana Allen, MS, CNS, Product Development Manager

Moss Nutrition Digest #34 – 10/2022 – PDF Version


  1. Boucher BJ. Vitamin D deficiency in British south Asians, a persistent but avoidable problem associated with many health risks (including rickets, T2DM, CVD, Covid-19 and pregnancy complications); the case for correcting this deficiency. Endocr Connect. 2022 Sep 1;EC-22-0234.
  2. Beard HH. The prophylactic effect of vitamins A and D upon the prevention of the common cold and influenza. J Am Diet Assoc. 1934;10:193–199.
  3. Baybutt RC, Standard JT, et al. Cod Liver Oil, but Not Retinoic Acid, Treatment Restores Bone Thickness in a Vitamin A-Deficient Rat. Nutrients. 2022 Jan 22;14(3):486.
  4. Linday LA. Cod liver oil, young children, and upper respiratory tract infections. J Am Coll Nutr. 2010 Dec;29(6):559-62.
  5. Fatia F, Memon A, et al. Role of Cod Liver Oil in Reducing Elevated Lipid Paramaters. Cureus. 2021 Jun 9;13(6):e15556.

Cod Liver Oil Products From Moss Nutrition

Icelandic Cod Liver Oil – Liquid Purified, pharmaceutical grade liquid cod liver oil from Arctic seas. Pleasant natural lemon flavor. 1 teaspoon serving size contains 1500 mcg RAE vitamin A (167% Daily Value), 11.5 mcg vitamin D (58% Daily Vaue), 1081 mg total omega-3 fatty acids. Available in 8 oz amber glass bottles. Refrigerate after opening.

Icelandic Cod Liver Oil – Capsules Purified, pharmaceutical grade cod liver oil from Arctic sea. 3 softgel serving size provides 900 mcg vitamin A (100% Daily Value), 6.9 mcg vitamin D (35% Daily Value), 645 mg total omega-3 fatty acids. Available in 90 softgel bottles.

Note: 1 tsp liquid = approximately 5 softgels