
Omega-3 supplementation. Answers to frequently asked questions.
Everything you always wanted to know but nobody ever told you.
There are many myths circulating in the media about omega-3 supplementation. It’s time to dispel them all. Read our answers to the most frequently asked questions and find out exactly what, how and when.
What exactly are omega-3 fatty acids, and what roles do they play in our bodies?
Omega-3 fatty acids are polyunsaturated fatty acids that the body cannot produce in sufficient quantities, so they must be obtained from the diet. The most biologically important forms are EPA and DHA. They perform many structural and regulatory functions in the body.
The key areas where omega-3 is effective:
Omega-3 fatty
acids are a component of the phospholipids that make up cell membranes. They influence membrane fluidity, intercellular communication and the proper functioning of receptors.
The brain and nervous system
: DHA is an important structural component of the brain and the retina. It supports healthy cognitive function and the development of the nervous system, particularly during pregnancy and childhood.
Gut
microbiota Research suggests that omega-3s may help maintain the balance of the gut microbiota and the integrity of the intestinal barrier, thereby complementing the effects of probiotics.
Cardiovascular system
: EPA and DHA support healthy heart function and help maintain healthy triglyceride levels when consumed in adequate amounts.
The immune system and inflammatory balance
Omega-3 fatty acids are precursors of compounds involved in suppressing inflammatory responses and maintaining immune balance.
The skin and the hydrolipid barrier: These
factors influence the condition of the skin, support the skin barrier and may affect the composition of sebum by regulating inflammatory mediators.
Prenatal
DHA plays an important role in the development of the brain and vision in foetuses and infants.
In practice, omega-3s have a systemic effect, as they play a role in fundamental biological processes at the cellular level.
Why is it important to take omega-3 supplements derived from fish or microalgae?
The most biologically significant forms of omega-3 fatty acids are EPA and DHA, which are found mainly in oily sea fish and microalgae. It is these long-chain fatty acids that are directly utilised by the body to build cell membranes, regulate inflammatory processes and support brain, heart and eye function.
Although plant-based products such as linseed oil and chia seeds contain ALA (a plant-based form of omega-3), the body’s ability to convert it into EPA and DHA is very limited. For this reason, direct sources of EPA and DHA — derived from fish or microalgae — are considered the most effective for daily supplementation.
Supplementation may be particularly important in the context of the modern diet. Most European adults, including Poles, do not meet the recommended intake of approximately 250 mg of EPA and DHA per day, mainly due to low consumption of oily sea fish. Population studies also indicate low levels of the so-called Omega-3 Index in Central European countries, suggesting a widespread deficiency of these fatty acids.
Fish oil or microalgae supplements provide EPA and DHA in a ready-to-use, biologically active form, making them a practical dietary supplement — both for people who eat little fish and for those on plant-based diets who choose omega-3 from algae.
Which omega-3 supplements are suitable for vegans?
For those on a plant-based diet, there are omega-3 supplements made from microalgae, which naturally contain DHA and EPA. This is a healthy and ethical alternative to fish oil.
How do omega-3 supplements differ from one another?
Not all omega-3 supplements are the same. They differ in terms of their chemical form, purity and degree of oxidation, EPA and DHA content, source, and form (capsules, liquid oil, gummies, etc.). All of these factors also affect their price.
What should you look out for when making a purchase?
Choosing the right omega-3 supplement is crucial to its quality and effectiveness. It is worth paying attention to a few key factors:
EPA and DHA content in a daily serving
What matters most is the actual amount of EPA and DHA, not the amount of fish oil itself. It is these two fatty acids that are responsible for most of the health benefits.
Independent quality certificates
Certificates such as IFOS or other laboratory testing schemes confirm the purity of the product, the accuracy of its composition as declared, and low levels of environmental contaminants.
Low oxidation levels (TOTOX index)
Omega-3s are sensitive to oxidation, so it is advisable to choose products with a low TOTOX index, which indicates the oil’s freshness and stability.
Source of raw material and purification process The origin of the oil (e.g.
wild marine fish or microalgae) is important, as are the purification methods used, which help to remove heavy metals and other contaminants.
Chemical form and bioavailability
Omega-3s can be found, for example, in the form of triglycerides or ethyl esters. The triglyceride form is the closest to the natural structure of the fats found in fish. It is well tolerated by the digestive system and is highly stable.
A supplement form tailored to individual needs:
Capsules are convenient to take, whilst liquid oil often allows for a higher daily dose of EPA and DHA. It is also often the only form acceptable to people who have difficulty swallowing capsules. It is therefore important for the manufacturer to offer a range of supplement forms.
Making an informed choice when selecting an omega-3 supplement allows you to tailor it more effectively to your individual needs and lifestyle.
What independent quality certifications might omega-3 supplements have?
IFOS – International Fish Oil Standards
This is one of the best-known independent fish oil testing schemes. IFOS certification means that the product has been assessed for:
- contaminants (heavy metals, dioxins, PCBs),
- compliance of the EPA and DHA content with the declaration,
- oxidation level (oil freshness),
- safety and quality.
This programme is regarded as one of the most rigorous standards for the assessment of fish oil in the world.
FOS – Friend of the Sea
This certification focuses primarily on the sustainable sourcing of raw materials and the protection of the marine environment. Among other things, it means:
- sustainable fishing,
- minimal impact on the ecosystem,
- monitoring of raw material sources.
This is an important factor for people who care not only about product quality but also about its environmental impact.
MSC – Marine Stewardship Council
The MSC certificate confirms that the fish used to produce the oil come from sustainably managed fisheries.
This mainly concerns environmental aspects:
- the protection of fish stocks,
- responsible management of ocean resources.
GOED – Global Organisation for EPA and DHA Omega-3
GOED is an international trade association representing omega-3 producers. Membership entails, amongst other things:
- adherence to high quality standards,
- checking the purity of raw materials,
- transparency in production.
Regular laboratory tests confirm the absence of contaminants and the high stability of the omega-3 oil.
When is the best time to take omega-3 – in the morning or in the evening?
The most important thing is to take them with a meal containing fat, as this improves absorption. The time of day is less important than taking them regularly.
Do omega-3s cause ‘fishy burps’?
This can happen if you use low-quality oils or take them on an empty stomach. Choosing a fresh product with a low TOTOX rating and taking it with food can help.
How long should you take omega-3 supplements?
Omega-3s are a dietary component, so they can be taken over the long term — particularly when intake of oily fish is low.
How should omega-3 supplements be stored to ensure they retain their properties?
Omega-3 fatty acids are sensitive to light, temperature and oxygen, which is why proper storage is crucial to their quality.
🧴 Liquid omega-3 oils
Before opening:
• store in a cool, shaded place,
• avoid high temperatures and direct sunlight.
Once opened:
• store in the fridge,
• always close the bottle tightly,
• use within the time recommended by the manufacturer.
Low temperatures slow down fat oxidation and help preserve freshness.
💊 Omega-3 capsules
Before and after opening:
• store at room temperature in a dry place,
• protect from light and moisture,
• if the ambient temperature exceeds 25 degrees, it is best to move the product to the fridge or another cooler place.
If the capsules develop a strong fishy or bitter smell, this may indicate that the oil has gone rancid.
Can omega-3 be taken alongside vitamins D and K2?
Yes — many people take them together as part of a single meal. As these ingredients are fatty in nature, they are best absorbed under similar conditions.
What is the TOTOX index?
TOTOX measures the degree of fat oxidation. A lower value indicates that the oil is fresher and that the omega-3 fatty acids are more stable. For example, the dietary supplement Norsan Arktis has a TOTOX value of 1.5, which is an excellent result and attests to the product’s superior quality.
I’m not sure if I need to take supplements. How can I find out?
Omega-3 levels in the body can be assessed using specialist laboratory tests that analyse the fatty acid profile in the blood. One example is the Omega Test, which determines the composition of lipids and the proportions of fatty acids in the body.
The test involves analysing the fatty acid composition of a blood sample. The laboratory uses advanced analytical techniques, such as gas chromatography, to accurately determine the levels of various types of lipids, including EPA and DHA.
The results of the study show, among other things:
- omega-3 levels,
- omega-3 to omega-6 ratio,
- trans fat index,
- additional markers of inflammation, e.g. the AA/EPA ratio.
The results are interpreted in the context of lifestyle, diet and health goals. This analysis enables a more personalised approach to diet and supplementation, particularly for those at risk of cardiovascular or metabolic diseases.
Sources:
- Calder P.C. Marine omega-3 fatty acids and inflammatory processes: Effects, mechanisms and clinical relevance. Biochimica et Biophysica Acta – Molecular and Cell Biology of Lipids. 2015;1851(4):469–484.
- Swanson D., Block R., Mousa S.A. Omega-3 fatty acids EPA and DHA: Health benefits throughout life. Advances in Nutrition. 2012;3(1):1–7.
- Schuchardt J.P., Hahn A. Bioavailability of long-chain omega-3 fatty acids. Prostaglandins, Leukotrienes and Essential Fatty Acids. 2013;89(1):1–8.
- Dyall S.C. Long-chain omega-3 fatty acids and the brain: A review of the independent and shared effects of EPA and DHA. Frontiers in Aging Neuroscience. 2015;7:52.
- Kulczyński B., Gramza-Michałowska A., Sidor A. The health benefits of omega-3 fatty acids. Food Industry. 2024;78(6).
- Zajdel A., Wilczok A. Interactions between omega-3 polyunsaturated fatty acids in the diet and the gut microbiota. Farmacja Polska. 2023.
- Jarosz M. (ed.). Dietary guidelines for the Polish population and their application. National Institute of Public Health – PZH; 2020.
- Expert articles available on the Norsan Polska website.









