The Health Benefits of Cod Liver Oil

Cod liver oil is a fish oil (or marine oil) that is high in DHA and EPA and contains vitamins A and D along with small amounts of vitamin E. 

Cod liver oil is one of nature’s richest sources of natural vitamins A and D: 

Vitamin A:

Vitamin A prevents blindness and other problems as well as skin disorders such as acne.  It enhances the immune system and may be helpful in healing gastrointestinal ulcers.  It protects against pollution and cancer formation and is needed for the maintenance and repair of epithelial tissues (of which skin and mucous membranes are composed).  Vitamin A is important for the formation of bones and teeth.  It is essential for strong bones and healthy teeth. Vitamin A is important for mineral absorption and aids in fat storage.  It has been shown to protect against colds and influenza as well as infections of the kidneys, bladder, lungs and mucous membranes.  Vitamin A is necessary for new cell growth and is important for slowing the aging process.  Lastly, the body cannot utilize proteins and water-soluble vitamins without vitamin A. 

A deficiency of vitamin A may be indicated if there is dry hair or skin, dryness of the conjunctiva and cornea, poor growth and/or night blindness are present.  Other possible results of vitamin A deficiencies include abscesses in the ears, insomnia, fatigue, reproductive difficulties, sinusitis, pneumonia and frequent colds, along with other respiratory infections, skin disorders (including acne) and weight loss.

Beta-carotene and other carotenoids (which can be obtained by eating certain vegetables and fruits) can be converted by the liver into vitamin A.  However, beta-carotene does not have the same activity in the body as vitamin A until it is converted.  Beta-carotene can be a precursor to vitamin A, yet it can also be converted to other substances or used as an antioxidant.  Beta-carotene and other carotenoids are not toxic in large doses as vitamin A can be; however, people with hypothyroidism as well as other health problems often have trouble converting carotenes into vitamin A.  Antibiotics, laxatives and many of the cholesterol-lowering drugs interfere with vitamin A absorption.

Vitamin A is found in animal livers and fish liver oil.  The carotenoids are found in many of the green and yellow/orange/red fruits and vegetables as well as many herbs.  Vitamin A is not found in any plant sources.  Conversely, carotenoids are not found in large amounts in animal food sources.

If you have liver disease, do not take a daily dose of over 10,000 IU of vitamin A in pill form or in liquid cod liver oil.  This rule also applies to pregnant women.  Children should not take more than 18,000 IU of vitamin A on a daily basis for over one month.  If you have hypothyroidism, avoid beta-carotene, because your body can probably not make the conversion to vitamin A. Cod liver is your best choice. 

Many Americans have hypothyroidism and do not know it.  Some estimate hypothyroidism affects over half the population of the United States.  If you are taking one teaspoon to one tablespoon of cod liver oil a day that is not highly processed, molecularly distilled or concentrated, you will have no trouble with overdosing on vitamin A or any other fat soluble vitamin. Synthetic vitamin A is much more a concern than natural vitamin A.  Please see what Dr. Mercola has to say on the subject.

It is important for consumers to know that, in late 1995, a direct link was made between synthetic vitamin A and birth defects.  This study lasted four years and involved 22,748 pregnant women. The results of this study show a 240-percent increase in birth defects when the women took 10,000 IU of synthetic vitamin A per day and a staggering 400-percent increase in risk from taking 20,000 IU per day. The researchers were very careful to point out that the risk from natural foods containing natural vitamin A was not the same.  In essence, they could not find a strong correlation.  Wilderness Family Naturals’ cod liver oil does not contain any added vitamin A, natural or synthetic. Every vitamin in our cod liver oil comes from the original oil obtained from the liver of the codfish.

To read about more relevant studies, please check out the following link:

http://www.marchofdimes.com/professionals/681_1152.asp

For an excellent article on Vitamin A please check out the Weston A. Price article

Vitamin D

Vitamin D is another fat-soluble vitamin. However, it is really not a vitamin, but rather a hormone, and since we can make it ourselves with the use of sunshine it is not a true vitamin at all. It is required for the absorption and utilization of calcium and phosphorus by the intestinal tract.  Cholecalciferol is the form found in vitamin supplements and fortified dairy products and not the hormonal form of vitamin D, namely 1,25-dihydroxycholecalciferol.

Natural vitamin D is necessary for growth and is especially important for the normal growth and development of bones and teeth in children.  It protects against muscle weakness and is involved in regulation of the heartbeat.  It is also important in the prevention and treatment of osteoporosis and hypocalcemia.  Vitamin D enhances immunity and is necessary for thyroid function and normal blood clotting. 

Research shows that healthy individuals who do not have a vitamin D deficiency demonstrate a more normal glucose metabolism than their vitamin D-deficient counterparts. Additionally, vitamin D is suggested to play a pivotal role in supporting normal muscle tone and strength.

The form of vitamin D that we get from supplements is not fully active.  It requires conversion by the liver and then by the kidneys before it becomes fully active.  This is why people with liver or kidney disorders are at a higher risk for osteoporosis. 

Natural vitamin D is made when the skin is exposed to the sun’s ultraviolet rays.  A cholesterol-based (hormone) compound in the skin is transformed into a precursor of vitamin D.  Exposing the face and arms to the sun for 15 minutes three times a week is suppose to be an effective way to ensure adequate amounts of vitamin D in the body.  Cod liver oil contains active vitamin D, also called vitamin D2.

Synthetic vitamin D (cholecalciferol) is also called vitamin D3.  To understand the differences in these two and to find more out about vitamin D click here.

For a good discussion on the toxicity of synthetic vitamin D, this site is a must-read.

The sad truth about synthetic “vitamins” is that they can be dangerous!! For example, there is a report on the test effects of vitamin D in 500 human pregnancy cases. All the women given synthetic D developed calcified and diseased kidneys, while women given natural vitamin D had no observable changes in the kidneys.   A good informational article can be found here. It contains the study mentioned above and a great deal of other information, along with many other studies. Wilderness Family Naturals’ cod liver oil does not contain any synthetic vitamin D.

A severe deficiency of vitamin D can cause rickets in children and osteomalacia (a similar disorder) in adults.  Lesser degrees of deficiency may be characterized by loss of appetite, a burning sensation in the mouth and throat, diarrhea, insomnia, visual problems and weight loss.  The recommended dosages for cod liver oil provide about 500 IU vitamin D for children, 1000 IU vitamin D for adults, 2000 IU vitamin D for pregnant and nursing women and up to 9000 IU for those taking large amounts of cod liver oil to deal with stress and disease.

Fish oils and fatty saltwater fish and eggs are natural sources of vitamin D.  Natural vitamin D is found in butter, cod liver oil, dandelion greens and egg yolks.  Other good food sources are halibut, liver, milk, oatmeal, salmon, sardines, sweet potatoes and tuna.  Herbs such as alfalfa, horsetail, nettle and parsley also contain the precursor to vitamin D.

Intestinal disorders, liver and gall bladder malfunctions interfere with the absorption of vitamin D. Individuals who have had their gall bladders removed will have significantly less vitamin A, D and E absorption. Cholesterol-lowering drugs, antacids, mineral oil and steroidal hormones such as cortisone also interfere with absorption.  Thiazide diuretics such as chlorothiazide (Diuril) and hydrochlorothiazide (Esidrix, HydroDiuril, and Oretic) disturb the body’s calcium/vitamin D ratio.

Vitamin D toxicity has been known to occur in people taking amounts over 65,000 IU a day for a period of years. (Please note that they were taking synthetic vitamin D.) Using natural cod liver oil, with no added A, D or E, you will never even come close achieving this level in your diet, even if you are eating many, many vitamin D-rich foods.

Weston A Price also has an excellent article on Vitamin D.

Vitamin E

Vitamin E is a fat-soluble vitamin primarily used as an antioxidant by the body.  It is important in the prevention of cancer and cardiovascular disease.  Vitamin E improves circulation, is necessary for tissue repair and is useful in treating premenstrual syndrome and fibrocystic disease of the breast.  It promotes normal blood clotting and healing.  It reduces scarring from some wounds, reduces blood pressure, aids in preventing cataracts, improves athletic performance and relaxes leg cramps.  It also maintains healthy nerves and muscles while strengthening capillary walls.  In addition, vitamin E promotes healthy skin and hair and helps to prevent anemia and retrolental fibroplasias, an eye disorder that can affect premature infants.

As an antioxidant, vitamin E prevents cell damage by inhibiting the oxidation of lipids (fats) and the formation of free radicals.  It protects other fat-soluble vitamins from destruction by oxygen, and aids in the utilization of vitamin A and protects it from destruction by oxygen.  It retards aging and may prevent age spots as well.

Vitamin E deficiency may result in damage to red blood cells and the destruction of nerves.  Signs of vitamin E deficiency can include infertility (in both men and women), menstrual problems, neuromuscular impairment, shortened red blood cell life span, spontaneous abortion (miscarriage) and uterine degeneration.  Low levels of vitamin E in the body have been linked to both bowel cancer and breast cancer.  Epidemiological links have been identified between the increase in the incidence of heart disease and the increasing lack of vitamin E in the diet due to America’s reliance on overly processed foods.

Natural vitamin E is actually a family of eight different related molecules that fall into two major groups, the tocopherols and the tocotrienols.  Within each group, there are alpha, beta, gamma and delta forms.  Of all eight of these molecules, it is the alpha form that is the most active/potent. Most cod liver oil manufacturers add vitamin E to their oil.  Usually this is either synthetic vitamin E or a blend of synthetic and natural vitamin E from soy.  For a discussion on the differences between synthetic vitamin E and natural vitamin E please click here.  For good information on the differences between synthetic vitamin E and natural vitamin E click here and here.

Wilderness Family Naturals’ cod liver oil does not contain any added vitamin E, natural or synthetic.  The vitamin E in our cod liver oil is that which was originally in the liver of the cod when the oil was collected.

Other sources of Vitamin E are dark green leafy vegetables, legumes, nuts, seeds and whole grains.  Significant quantities are also found in brown rice, cornmeal, dulse, eggs, kelp, desiccated liver, milk, oatmeal, organ meats, sweet potatoes, etc.  Herbs that contain vitamin E include alfalfa, bladderwrack, dandelion, dong quai, flaxseed, nettle leaf, oat straw, raspberry leaf and rose hips.

The body needs zinc in order to maintain the proper level of vitamin E in the blood.  If you take both vitamin E and iron you may need to take these at different times of the day.  Inorganic forms of iron such as ferrous sulfate destroy vitamin E.   Organic iron (ferrous gluconate or ferrous femarate) does not harm vitamin E.  When you are obtaining your vitamins, such as vitamin E from a natural source like cod liver oil, you usually do not need to worry about these types of imbalances.

If you are taking anti-coagulant medications (blood thinners), do not take more than 1200 IU of vitamin E daily. This should not be a problem if your vitamin E is coming from food sources and not supplements.  If you suffer from rheumatic heart disease or an overactive thyroid gland, do not take more than the recommended dose.  If you have high blood pressure, start with a small amount, such as 200 IU daily, and increase slowly to the desired amount.  Again, it is the supplements that you need to watch out for; natural foods such as cod liver oil that are rich in vitamin E will be safe.

Wilderness Family Naturals’ cod liver oil is also rich in the essential fatty acids:

DHA and EPA
DHA and EPA are made by the body from the omega 3 “essential fatty acid” alpha-linolenic acid.  Alpha-linolenic acid is an 18-carbon chain fatty acid.  It is called an omega 3 fatty acid because the third carbon from the omega end is where you find the first double bond.  The alpha end is the end where the carboxylic acid is found, and the omega end is at the opposite side.  (Alpha is the first letter in the Greek alphabet and omega is the last letter of the alphabet).  When the body converts into EPA, the fatty acid is transformed from the 18-carbon chain fat to a 20-carbon chain fat and from a 3-double-bonded chain to a 5-double-bonded chain.  The body further changes it into a 22-carbon chain, 6-double-bonded molecule called DHA.

DHA and EPA have several actions in a number of body systems: 
Both of these fatty acids lower triglyceride levels.  They help to promote a healthy cardiovascular system and have anti-arrhythmic properties.  Cod liver oil is used by many people who have suffered from myocardial infarctions (heart attacks).  All fish oils decrease clotting tendencies of the blood and lower blood pressure.  DHA and EPA are important for maintenance of normal blood flow because they lower fibrinogen levels and prevent platelet stickiness. 

In addition, both EPA and DHA have anti-inflammatory and immune-modulating properties.  Cardiovascular disease is directly linked to inflammatory processes taking place in the body and the lining of the arteries that “plaque up” are greatly affected by inflammation.  The anti-inflammatory effects of DHA and EPA not only help reduce arterial inflammation, but have also been used for rheumatoid arthritis, ulcerative colitis and Crohn’s disease. In people with rheumatoid arthritis, fish oil promotes joint movement and mobility, assists with improving functional status and helps reduce pain medication requirements. It has been shown to reduce pain levels during menstruation. It is interesting to note how often someone with these types of inflammatory problems “eventually” develops heart disease. 

DHA is vital for normal brain development in both the fetus and infant.  It is also very important for the maintenance of normal brain function throughout life.  DHA appears to be a major determinant of membrane fluidity in brain cells, and this could play a major role in the maintenance of normal cognition and mood.  Fish oils have been used in the treatment of bipolar disorder.  EPA and DHA appear to dampen signal transduction associated with phosphatidylinositol and arachidonic acid.  The DHA and EPA (especially the DHA) become incorporated into the phospholipids of the membranes of the cells involved in cell-signaling pathways.

Long-chain fatty acids from sources other than fish oil are known risk factors for cancer as well as cardiovascular disease.  However, the opposite appears to be true with fish oils. Instead, these fatty acids are essential for proper body functions.  EPA is essential for the production of prostaglandins, which are hormones that direct many important processes in the cells. DHA is vital for the healthy development and functioning of the nervous system and brain. EPA and DHA have anti-inflammatory effects and may act as a blood thinner. Fish Oil supports the body in achieving normal triglyceride levels.   DHA and EPA are important to the musculoskeletal, gastrointestinal and immune systems and are cancer-reducing.

DHA and EPA are used by the body mainly for the synthesis of phospholipids.  These phospholipids are incorporated into the cell membrane of red blood cells, platelets and CNS cells, among others.  EPA and DHA are mainly found in the phospholipid components of the cell membranes.  The brain uses DHA in preference to other fatty acids.  DHA can partially retro convert to EPA and EPA can partially convert to DHA.

The Weston A Price organization has a wonderful article written by a clinical nutritionalist on cod liver oil.  It is a must-read for anyone interested in more information.

References:
Adler AJ, Holub BJ.  Effects of garlic and fish-oil supplementation on serum lipid and lipoprotein concentrations in hypercholesterolemic men. Am J. Clinical Nutr.  1997; 65:445-450

Appel LJ, Miller ER III, Seidler AJ, Whelton PK. Does supplementation of diet with fish oil reduce blood pressure?  A meta-analysis of controlled clinical trials.  Arch Intern Med 1993; 153:1429-1438

Ariza-Ariza R, Mestanza-Peralta M. Cardiel MH.  Omega-3 fatty acid in rheumatoid arthritis: an overview.  Semin Arthritis Rheum.  1998, 27:336-370

Belluzi A. Brignola C. Campieri M. et al. The hypotriglyceridemic effect of fish oil in adult-onset diabetes without adverse glucose control. Ann NY Acad Sci. 1993; 683:337-340

Curtis CL, Hughes CE, Flannery CR, et al. n-3 Fatty acids specifically modulate catabolic factors involved in articular cartilage degradation.  J Biol Chem 2000; 275:721-724

Skuladottir GV, Gudmundsdottir E, Olafsdottir E et al. Influence of dietary cod liver oil on fatty acid composition of plasma lipids in human male subjects after myocardial infarction. J Intern.Med. 1990;228:563-8.

Burchard HU, Tischendorf FW. The effects of the intake of cod liver oil on the blood lipid level, the lipoprotein profile and bleeding time. Z.Ernahrungswiss. 1989;28:84-91.

Gudbjarnason S, Benediktsdottir VE, Skuladottir G. Effects of n-3 polyunsaturated fatty acids on coronary heart disease. Bibl.Nutr Dieta 1989;1-12.

Akpede GO, Omotara BA, Ambe JP. Rickets and deprivation: a Nigerian study. J R.Soc.Health 1999;119:216-22.

Watkins BA, Lippman HE, Le Bouteiller L, Li Y, Seifert MF. Bioactive fatty acids: role in bone biology and bone cell function. Prog.Lipid Res. 2001;40:125-48

Sigurdsson G, Franzson L, Steingrimsdottir L, Sigvaldason H. The association between parathyroid hormone, vitamin D and bone mineral density in 70-year-old Icelandic women. Osteoporos.Int. 2000;11:1031-5.

Singer P, Berger I, Gerhard U, Wirth M, Moritz V, Forster D. Changes of N-6 and N-3 fatty acids in spontaneously hypertensive (SHR) and normotensive rats after diets supplemented with alpha-linolenic or eicosapentaenoic acids. Prostaglandins Leukot.Med. 1987;28:183-93.

Terkelsen LH, Eskild-Jensen A, Kjeldsen H, Barker JH, Hjortdal VE. Topical application of cod liver oil ointment accelerates wound healing: an experimental study in wounds in the ears of hairless mice. Scand.J

Knapp HR and others. The Effect of Cod liver oil on the Development of Atherosclerosis in an Animal Model. Proceedings of the AOCS, Ed WEM Lands, AOCS 1987, pp 35-40.

Veierod MG, Laake P, Thelle DS. Dietary fat intake and risk of lung cancer: a prospective study of 51,452 Norwegian men and women. Eur J Cancer Prev 1997 Dec;6(6):540-9.