Fish Oil

How Is Fish Oil Produced?

The potential benefits of taking fish oil supplements include a lowered risk for heart attack and stroke in those with cardiovascular disease. Fish oil may also lower triglycerides and blood pressure, as well as slow plaque buildup in the arteries. You get similar benefits from consuming fatty fish such as tuna, trout, herring and salmon, so you may not need supplements if your diet is rich in fish oil sources. The primary method for extracting oil from fish is the wet pressing method, according to the Food and Agriculture Organization of the United Nations.

Wet Pressing Method

Before oil can be extracted, the fish are heated to approximately 95 degrees Celsius to separate water and oil from protein. The liquid extraction, referred to as press liquor, contains water, oil, dissolved protein, vitamins and minerals. The oil is separated from other liquids by centrifuge, which separates matter of varying densities. The oil is stored in tanks and the concentrated leftover liquid matter gets mixed with the solid fish matter to produce fish meal.


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Steaming is the primary method for heating fish for fish oil production. Although the wet pressing method yields a larger amount of fish oil, oil, water and solid material released during steaming is also strained to separate liquid from solid matter. If press liquor is stored in a tank, the sludge settles at the bottom and the oil rises to the top. This process is time-consuming, however, and yields a higher percentage of impurities in the oil. Centrifugation speeds up the process and creates a more pure fish oil product.


Fish that are smaller than 16 inches are sent directly to the steamer, while larger fish are hashed prior to processing. The cooking process takes approximately 15 to 20 minutes. When solids are separated from liquids, roughly 70 percent of the raw material is press liquor; the protein and bones account for the other 30 percent. The oil-free portion of the press liquor, including dissolved proteins and other nutrients, goes through an evaporation process before being added to other dry materials for meal production.


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Certain types of fish, including king mackerel, shark and farm-raised salmon, are more likely to be contaminated with mercury or other toxins; however, fish oil supplements are generally free from these contaminants, according to MedlinePlus. While fish oil can provide health benefits, high doses of fish oil may interfere with blood clotting, impair immunity, increase low density lipoprotein cholesterol or cause an allergic reaction in people with fish or seafood allergies. While up to 3 grams is generally considered a safe dosage, work with your doctor to determine the right dosage for you based on your health needs.

Fish Oil Manufacturing Process | Molecular Distillation

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What type of fish does Nordic Naturals use in its products?

Since our founding, Nordic Naturals has always been committed to sourcing only fish species that are flourishing and only from waters that are not threatened by overfishing. Nordic Naturals cod liver oil products are made from 100% wild Arctic cod (Skrei) that are sustainably sourced from the Norwegian Sea. All other Nordic Naturals products are made from wild, sustainably sourced sardines and anchovies from the South Pacific and Atlantic Oceans. For more detailed information about our fishing practices and the regulations of the Norwegian Government fisheries management system, please visit our Why Omega-3s page.

How long does it take Nordic Naturals products to get from fish to soft gel or bottle?

A primary goal for Nordic Naturals is to optimize freshness levels in our fish oils. We strive to minimize the time from catch to processing, and ideally the fish is processed within hours of being caught. During processing, we consistently monitor freshness levels of the raw material using acidity levels (an accurate measure of freshness). Even though standard acidity allowance is 3.0, Nordic Naturals does not allow more than 1.0. While complete processing may take days, our raw material is protected in a nitrogen environment at every stage of manufacturing to maintain optimal freshness in the final product.

How is mercury (and other toxins) removed from the fish oil?

Molecular distillation removes impurities (heavy metals, dioxins, etc.), saturated fats, and other undesirable organic compounds. Molecular distillation is gentle with exceptionally low heat residence time and is performed in a vacuum to further reduce heat requirement. All time and temperature specifications are proprietary, but we can assure you that no trans fats are created during any of our distillation processes. Any potential impurities and saturated fats are distilled out of the oil, leaving only the key beneficial components of the fish oil. Flash distillation accomplishes the same thing as molecular distillation, but utilizes steam rather than a vacuum. The process used depends on the intended concentration of the fish oil. Molecular distillation is used for all of our fish oil products. Flash distillation is used for our non-concentrated fish oils. Independent lab results consistently show that these processing techniques deliver oils of exceptional quality and freshness. Certificates of Analysis are available on our website; simply enter your lot number to view the certificate for your specific bottle.

Does Nordic Naturals manufacturing process damage the fish oil or remove beneficial compounds? Does it use high heat?

Molecular distillation (used for all of our fish oil products) removes environmental toxins like mercury and other heavy metals, dioxins, etc., saturated fats, and other undesirable organic compounds, leaving behind only the key beneficial components of the fish oil. It is a gentle distillation process with exceptionally low heat residence time, and is performed in a vacuum to further reduce the heat requirement. Flash distillation (used for our non-concentrated fish oils) accomplishes the same thing as molecular distillation, but utilizes steam rather than a vacuum.

All fish oil‚ regardless of the kind of manufacturing process used‚ needs to be processed in order to remove contaminants and pass minimum laws and standards (such as California’s Proposition 65). This process always requires the use of heat. However, heat itself does not cause oxidative damage to the fish oil‚ it can only affect the rate of oxidation. Without the presence of free radicals or oxygen, there is no oxidation to speed up. This is also why nitrogen-flushed fish oils can handle being shipped, delivered, and stored in even the hottest climates and still taste great.

Third-party testing for TOTOX values will reliably show the total oxidation to which the oil has been exposed, and will thereby reliably assess the quality of any processing technique. (For more information on TOTOX values, see below.) Perhaps even more important is the absence of a fishy taste. It has been verified that the most significant and sensitive pieces of equipment that measure oxidation in oils are still not nearly as sensitive as the human palate [From the AOCS meeting 2007]. The aldehyde byproducts of oxidative damage to fish oils have a high vapor pressure (thus the fish burp) and the distinctly disagreeable taste and smell of rancid fish.

What is the difference between molecular distillation and CO2 processing?

Molecular distillation removes impurities (heavy metals, dioxins, etc), saturated fats, and other undesirable organic compounds, leaving behind only the key beneficial components of the fish oil. It is a gentle distillation process with exceptionally low heat residence time, and is performed in a vacuum to further reduce the heat requirement. Flash distillation accomplishes the same thing as molecular distillation, but utilizes steam rather than a vacuum.

CO2 extraction or fractionation starts with oil that has previously undergone either molecular distillation or flash distillation to remove impurities. It uses a combination of pressure and heat to concentrate the amount of omega-3s (EPA and/or DHA) in the oil, extracting the ethyl esters from the fish oil in order to increase their concentration.

Nordic Naturals does not use CO2 extraction because it has not been shown to provide a superior quality product. Independent lab results consistently show that our processing techniques deliver oils of exceptional quality and freshness. Certificates of Analysis are available on our website; simply enter your lot number to view the certificate for your specific bottle.

What is the difference between molecular distillation and cold-pressed fish oil?

Please see questions above for information about molecular distillation. All fish oil‚ regardless of the kind of manufacturing process used, needs to be processed in order to remove contaminants and pass minimum laws and standards (such as California’s Proposition 65). This process always requires the use of heat. This includes so-called “cold-pressed” fish oils. Cold-pressed oil also must also use heat during processing to turn the raw material into oil and remove impurities to pass minimum laws and standards.

Nordic Naturals does not use “cold-pressed” processing because it has not been shown to provide a superior quality product. Independent lab results consistently show that our processing techniques deliver oils of exceptional quality and freshness. Certificates of Analysis are available on our website; simply enter your lot number to view the certificate for your specific bottle.

What is the “gold standard” of Nordic Naturals Cod Liver Oil?

Nordic Naturals cod liver oil is made from 100% wild Arctic cod. No fish body oils or synthetic vitamins or additives are ever used. No other brand can honestly make the same claim. Over the past decade, we have perfected our three-step Gold Standard system that allows Nordic Naturals Arctic Cod Liver Oil to surpass even the strict European Pharmacopoeia Standard for purity and freshness:

First, we have built a direct relationship with smaller, independent fishermen, rather than larger trawling vessels, to ensure sustainable harvesting and less time spent at sea.

Second, we are able to minimize oxidation to the greatest degree possible by using nitrogen at every stage of manufacturing to protect the oil from oxygen and decomposition.

Last, since our MSC-certified processing facility in Norway is located right next to the harbor, we are able to keep transportation time at a bare minimum. A few short hours after being caught, the sustainably sourced Arctic cod are delivered whole for immediate processing.

This Gold Standard system enables us to deliver unmatched freshness levels. Third party testing reveals our Arctic Cod Liver Oil to have anisidine values (AV) between 1 and 2—that’s five to ten times below the industry average. AV is a measure of oxidation of the oil, so the lower the number, the fresher the fish oil. Certificates of Analysis are available on our website; simply enter your lot number to view the certificate for your specific bottle.

What does “anisidine value” and “totox value” mean?

Anisidine value (AV) is a measurement of past oxidation of the oil. More specifically, it is the measure of aldehyde production during oxidation of fats. AV essentially reflects how an oil has been handled and stored, versus peroxide value (PV), which measures current oxidation. For both AV and PV, a lower number is better. TOTOX (total oxidation value) is used to describe total oxidation to which the oil has been exposed. TOTOX = 2 x PV + AV.

The fish oils used in Nordic Naturals’ products typically range between TOTOX values of 5 and 14. Recent tests of Nordic Naturals raw fish oils report TOTOX values of 7.0. Certificates of Analysis are available on our website; simply enter your lot number to view the certificate for your specific bottle.

The established upper limits, as set by the current Voluntary Standards for Omega-3s* in the United States, are as follows:

Peroxide value: Maximum is 5 mEq/kg

Anisidine value: Maximum is 20 mEq/kg

TOTOX: Maximum is 26 mEq/kg

*Council for Responsible Nutrition 2006 Voluntary Monograph

Where are Nordic Naturals products manufactured and encapsulated?

100% of Nordic Naturals fish oil is manufactured in Norway. Nordic Pharma, Nordic Naturals’ new omega-3 manufacturing plant in Arctic Norway, is one of the most advanced processing plants in the omega-3 industry. Wholly owned and operated by Nordic Naturals, Nordic Pharma is a custom-designed, state-of-the-art plant built to pharmaceutical grade standards. All of our liquid and soft gel products are bottled and encapsulated at our plant in Southern California. All of our gummy products are manufactured in the United States.

Does the color of fish oil have anything to do with its quality?

The color of any fish oil results from the species of fish that is used to produce it. Fish species that have colored flesh will produce fish oil of similar color. The color of the oil is no indication of quality. Only third-party testing for purity and freshness will reliably show the quality of a fish oil product.

Why are the lemon Nordic Naturals soft gels cloudy while the strawberry and unflavored soft gels are clear?

In many Nordic Naturals formulas, we use natural fruit flavorings to enhance the palatability of our oils. This process involves adding these flavorings to both the oil and to the soft gel itself. These flavorings are derived from natural fruit essences, and differ slightly depending on the fruit used. The natural lemon flavor, for example, takes on a cloudy appearance when combined with fish oil, whereas the strawberry flavor does not.

Why is there a brown spot in my soft gel?

In all Nordic Naturals formulas, we use natural antioxidants (vitamin E for example) to help preserve the freshness of the oil. In many formulas, we also use natural fruit flavors to augment the palatability of our oils. Because these natural components are present in the soft gels, occasionally they can collect and concentrate at a specific point in the soft gel—which can create a discolored spot. This spot may dissipate when shaken, or may stay in a fixed place in the event that the spot adheres to the wall of the soft gel.

Enteric coating of fish oil soft gels has become popular. Is it important or necessary?

Enteric coating uses various compounds to coat the outside of soft gels in order to prevent them from being dissolved by stomach acids, so that the soft gel passes through the stomach to the small intestine where it will then dissolve. We believe the main reason why fish oil soft gels are enteric coated is to prevent repeat or burping. It is possible that enteric coating may be used to hide the fishy repeat associated with low quality/rancid oils with high TOTOX numbers. Fresh fish oil with low TOTOX values does not need to be masked. It is also important to note that consumers with sub-optimal digestion may not digest and absorb fish oil from an enteric-coated capsule.

Which Nordic Naturals fish oils are concentrated and which are not?

Nordic Naturals offers all our Arctic Cod Liver Oils in their natural concentrations, simply purified. Nordic Naturals fish body oils that are also sold as non-concentrates are: Omega-3 (and Omega-3D™), Complete Omega™ (and Complete Omega-D3™), Complete Omega™ Junior (and Complete Omega-D3™ Junior), Omega Woman®, and Omega-3 Pet™. Our omega-3 gummy products are not concentrated. All other Nordic Naturals fish oil products offer various concentrations of EPA and/or DHA.

Why doesn’t Nordic Naturals include niacin in their Nordic Berries Multivitamin?

The simple answer is that niacin in this supplement isn’t necessary. Here’s why:

Children 1–10 yrs. need about 6–12 mg/day and this is easily accomplished with a normal diet (and can also convert from tryptophan). Secondly, it only takes 10–20 mg/day of supplemental niacin to cause a skin flushing, GI upset, and possible mild liver damage.

The Food and Nutrition Board sets the upper limit at about 10–15 mg/day for children 1–8yrs. So it’s likely that if niacin were in this supplement, its RDA would be reached and easily exceeded (since Nordic Berries taste so good)!

Why does Nordic Naturals add vitamin d3 to many of their fish oils?

There is growing concern in the medical and scientific community about the prevalence of vitamin D deficiency. In 2008, the American Academy of Pediatrics doubled its vitamin D recommendations for infants, children, and adolescents to 400 I.U.s a day in response to the mounting consensus that vitamin D deficiency is an under-recognized epidemic.

In response, Nordic Naturals offers vitamin D3 products (which do not contain fish oil) for children and adults who do not receive adequate sun exposure, in a dose that experts recommend—1000 I.U.s per serving. And we’ve also introduced several fish oil + vitamin D3 formulas that deliver 1000 I.U.s of vitamin D3 per serving, in addition to the omega-3s EPA and DHA.

We use the D3 (or cholecalciferol) form of vitamin D in our products because it is the natural and most easily absorbed form, which the body makes from sunlight. Long known for its role in enhancing the absorption of calcium and phosphorus for strong bones, vitamin D is also linked to a variety of other functions in optimizing health, including the regulation of the immune and neuromuscular systems, and the modulation of mood and sleep rhythms.

Do Nordic Naturals products and containers contain phthalates?

No. Phthalates are plasticizers sometimes used in the manufacturing of plastic piping and industrial equipment. They have been in the news recently for their illegal use in some parts of Southeast Asia. Nordic Naturals is committed to the safety and efficacy of our products.

Nordic Naturals products and plastic containers do not use phthalates in any stage of our process. The US EPA and the World Health Organization have strict guidelines regarding phthalates and Nordic Naturals has always adhered to these standards.

The Slippery Facts about Fish Oil

Recently, fish oil has become a very popular supplement because of its documented cardiovascular and ocular health benefits. Most health benefits from fish oil consumption are associated with the long-chain omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA and DHA are critical to overall wellness because they help modulate the inflammatory system.

It is estimated that the average American consumes between 100mg to 200mg of omega-3 fatty acids per day.1-3 Humans cannot naturally synthesize omega-3 fatty acids, so dietary consumption is nescessary.1,2

The majority of omega-3 fatty acid intake comes from alpha linolenic acid (ALA) sources, such as flaxseed oil. Unfortunately, conversion of ALA to the essential EPA and DHA forms is very inefficient.4 So, consumption of fish and fish oil is the most effective way to attain appropriate dietary levels of EPA and DHA. In spite of dramatic evidence regarding the health benefits of omega-3s from fish oil, the FDA has not officially established guidelines regarding its recommended daily allowance (RDA).

Several health-related issues associated with regular fish consumption have surfaced during the last five years, including the ingestion of fish that are caught in polluted streams, lakes and bays. Bottom-feeding coastal fish are more susceptible to contamination by chemicals and toxins than fish that feed at higher water levels. So, open-water, or pelagic, fish are the most ideal for human consumption.

Because of several underlying factors, including geographic location, income level or unconventional dietary preferences, frequent fish consumption is not a realistic option for everyone.

Fortunately, however, fish oil supplements have become a reasonable alternative to dietary fish intake.

General Recommendations

The American Heart Association (AHA) recognizes the benefits of omega-3 fatty acids. The AHA recommends that:5

• All adults eat fish (particularly fatty fish) at least two times a week. Fish is a good source of protein and is low in saturated fat. Fish, especially oily species like mackerel, lake trout, herring, sardines, albacore tuna and salmon, provide significant amounts EPA and DHA.

• Patients with documented coronary heart disease should receive one combined gram of EPA and DHA per day. This may be obtained from the consumption of oily fish or from omega-3 fatty acid capsules.

• An EPA/DHA supplement may be useful in patients with hypertriglyceridemia. Two to four grams of EPA/DHA per day can lower an individual’s triglycerides by 20% to 40%.

Just remember, patients who take more than three combined grams of EPA and DHA per day should consult a physician about potential side effects, such as gastrointestinal distress.

Fish Oil Fundamentals

Because of the potential for pollutant contamination, fish oil must be distilled and pasteurized. Here is a general overview of the distillation process:6

1. Crude fish oil (many different variations) is altered with ethanol.

2. This mixture is then heat-distilled under a vacuum to remove contaminants.

3. The resultant liquid contains concentrated omega-3 molecules in an ethyl ester package.

4. The liquid is then manipulated to closer simulate a natural long-chain omega-3 fatty acid composition.

During the distillation process, the raw fish oil is broken down, cleansed, then reformulated into two basic products––ethyl ester (EE) and triglyceride (TG). The body recognizes both products and utilizes specific enzymes to create an absorbable form of the omega-3 fatty acid. The rudimentary purpose of the distillation process is to create a supplement that demonstrates:

• Safety and tolerability.

• High concentrations of EPA and DHA with minimal side effects.

• Optimal bioavailability.

• Overall stability.

• Affordability.

Triglycerides vs. Ethyl Esters

• Triglycerides. TGs are the molecular form of dietary fats that are found in most foods. In fact, the omega-3 fats found in all species of fish are exclusively TGs.7 TGs are comprised of three fatty acids that are linked to a molecule of glycerol. Because fatty acids are rapidly oxidized or highly unstable, the glycerol backbone helps to stabilize the fat molecules and prevent breakdown and oxidation.8

• Ethyl esters. EEs are synthetically derived by reacting fatty acids with ethanol to create an alternate form of fat.9 These alternative fats are created during the processing of some fish oils. In this case, natural fatty acids are cleaved from their glycerol backbone and linked to a molecule of ethanol––a process known as esterification.10 Following esterification, the fats contain higher concentrations of EPA and DHA than before processing. The resultant semi-synthetic EE product is then commonly sold as omega-3 fish oil concentrate.9

To effectively create TG fish oil, however, the distilled EEs must be re-esterified to remove the ethanol backbone and reestablish a glycerol backbone, which adds to the cost of production. Fortunately, in most cases, manufacturers will indicate if their fish oil capsules are either TG- or EE-based.

Metabolism of Fatty Acids

So, which form of fish oil offers the highest level of bioavailability? To answer this question, we must first assess the physiology of absorption and metabolism of TGs and EEs.

• TG fish oil. Re-esterified TG (rTG) fish oils are digested in the small intestine by the emulsifying action of bile salts and the hydrolytic activity of pancreatic lipase. This process leaves two fatty acids and a monoglyceride in the intestinal fluid, which are absorbed when combined with bile acids. The fatty acids and monoglycerides form complexes with bile salts called micelles. Absorbed within the enterocyte (intestinal cells) of the small intestine, the micelles are packaged with cholesterol and lipoproteins to form chylomicrons. Next, the chylomicrons move to the lymph system, where they enter the bloodstream and are passed to the liver. From the liver, the chylomicrons are converted into very low-density lipoproteins (VLDL) and low-density lipoproteins (LDL) for tissue delivery via the circulatory system.7,11,12

• EE fish oil. Digestion of EE fish oils is slightly different, however, because they lack a glycerol backbone.7 In the small intestine, the pancreatic lipase hydrolyzes the fatty acids from the ethanol backbone; however, this fatty acid-ethanol bond is up to 50 times more resistant to pancreatic lipase than the acid-glycerol bond found in rTG fish oil. As a result, human metabolizing of EE fish oil is somewhat inefficient.7,13

When metabolized, EE fish oil produces free fatty acids (FFAs) as well as ethanol. The fatty acids are taken up by the enterocytes and must be reconverted to TGs to be effectively transported in the blood. Thus, EE fish oil requires a monoglyceride substrate from another naturally occurring source, whereas the rTG form contains its own substrate.

Research on Bioavailability

Numerous studies have assessed the absorption and bioavailability of both TG and EE fish oils by measuring the amount of EPA and DHA in the blood plasma after ingestion. Many of these studies have yielded conflicting, somewhat controversial information.

Two studies published in the early 1990s showed that absorption rates of EPA and DHA from both natural TG and EE fish oil sources were virtually identical.14,15 Then, in 1993, a similar study showed that EPA and DHA absorption from EE fish oil was comparable to that from natural TG; however, the TG variants delivered better bioavailability with a lower concentration of fatty acids.16

A more intensive study published in 1990 presented conflicting data from a randomized, triple cross-over trial that examined the bioavailability of EPA and DHA from TG fish oil, EE fish oil and FFAs.17 Compared to the TG form, the mean relative bioavailability of EPA/DHA measured 186%/136% from free fatty acids and 40%/48% from EE. When compared to the TG form, maximal plasma levels were 50% higher from free fatty acids and 50% lower from EE.

Additionally, data from a similar study published in 2003 reaffirmed that EPA and DHA absorbed from rTG salmon oil were more effectively incorporated into plasma lipids than EPA and DHA from EE fish oil capsules.18 In general, both studies suggested that TG fish oil demonstrated nearly twice as much overall bioavailability than EE fish oil.17,18

A major double-blinded, randomized, placebo-controlled study published in 1995 assessed the bioavailability of the five most common fish oil concentrates––rTG, EE, FFA, fish body oil (FBO) and cod liver oil (CLO).19 In this study, 72 healthy subjects received daily doses of one of the five fish oil preparations or a corn oil control supplement for two weeks. The researchers estimated that all subjects received an average of 3.34 g of EPA and DHA per day. (See “Dosage and Composition Statistics of Five Fish Oil Concentrates,” below.)

The patients were examined in the morning following an overnight fast at both baseline and two-week follow-up.

Under these testing conditions in a fasting state, the concentration of EPA+DHA was highest in the rTG group and lowest in the corn oil control group. The results showed that that the unadjusted mean relative bioavailability EPA+DHA was 73% from EE, 91% from FFA and 124% from rTG. After adjustment for dosage factors, the mean relative bioavailability was 76% from EE, 86% from FFA and 134% from rTG.

These results indicate that the absorption of EPA+DHA from rTG is 1.763 times higher than that from EE. Even more interesting, rTG performed better than naturally occurring TG from FBO and CLO supplements.19

Considerations for Optimal Absorption

Another bioavailability issue involves both how and when fish oil is consumed. For example, one study showed that just 20% of available EPA and DHA is absorbed from EE fish oil supplements––unless taken with a high-fat meal (a high-fat meal raised absorption to 60%).18

Likewise, rTG fish oil demonstrates varied absorption rates when consumed with high-fat meals. In one study, EPA absorption from rTG supplements increased from a base level of 69% to 90% when consumed with a high-fat meal; DHA absorption was unaffected.20

While this is compelling research, it is ill advised to regularly consume high-fat meals simply to increase omega-3 absorption. Nonetheless, these studies underscore the importance of taking a fish oil supplement during a meal rather than individually between meals.

Product Stability

Keep in mind that all fish oils are particularly susceptible to oxidation, which reduces the product’s stability and bioavailability. Because of this, vitamin E is often added as a natural preservative.21

In general, fish oil has a six-month shelf life. In fact, an overly fishy taste is one indication of age-related oxidation. Sometimes, an enteric coating may mask this fishy taste.

According to one report, DHA from EE fish oils was much less stable than DHA from rTG fish oils.22 Specifically, the study indicated that DHA from EE fish oil was more reactive and quickly oxidized, suggesting that expired EE fish oils could more readily produce harmful oxidative products.22

Another study compared the stability of DHA in phospholipid, triacylglycerol and EE fish oils. After a 10-week oxidation period, DHA from EE fish oil decayed 33% more rapidly than DHA from the other two fish oils.23

The Economics of Fish Oil Supplementation

Many clinicians and patients have raised the point that rTG fish oil is more expensive than EE fish oil. This could be attributed to the extra costs involved in re-esterifying EE fish oil back to TG. While this may be true, we have to consider absolute costs, because rTG fish oil is absorbed significantly better than EE fish oil.

Let us assume that we want a patient to take 1,000mg of EPA. If we employ the previously outlined human absorption statistics, this patient would experience 134% bioavailability from rTG fish oil and 76% bioavailability from EE fish oil. In other words, rTG fish oil has a 1.7 times higher bioavailability factor than EE fish oil.

So, our patient would actually have to consume 1,700mg of EPA from EE fish oil supplements to achieve his target intake of 1,000mg.

From an economics standpoint, you can easily compare the prices of several commercially available fish oil products. (See “Costs of 1,000mg of EPA Using the Bioavailability Factor of 1.7” and “Costs of 1,000Mg of EPA Without Using the Bioavailability Factor of 1.7,” left.)

When adjusted for the bioavailability factor of 1.7, there is no great cost difference between products 1, 3 and 4. Without question, the most economical supplement in both assessments is product 2––optimal absorption levels at the lowest overall cost.

The bottom line––either with or without adjusting for the bioavailability factor, you should assume some role in determining the highest level of bioavailability at the most affordable price for your patients.

Essential fatty acids, such as EPA and DHA, are critical to the maintenance of health. However, most diets are woefully low in long-chain omega-3 fatty acids. Therefore, many individuals could benefit tremendously from eating more foods rich in omega-3s or supplementing with fish oil capsules.

Just remember, not all fish oil supplements are created equal. By and large, the literature suggests that natural TG or rTG fish delivers higher concentrations of EPA and DHA than EE fish oil. However, several other factors, such as patient safety, product stability and affordability, should also be considered when selecting a fish oil supplement.

Dr. Alexander is the senior director of education development for Optovue, Inc., the ophthalmic digital imagining company. He is not a paid consultant for any pharmaceutical or nutraceutical companies.

Eric Carter