Vitamin F – properties, effects, role in the body

Vitamin F is a traditional term for essential fatty acids (EFAs), primarily linoleic acid (LA) from the omega-6 family and alpha-linolenic acid (ALA) from the omega-3 family. These are compounds that the body cannot synthesise on its own and must be obtained from the diet. This is why these fats are often referred to as vitamins. Originally, vitamin F also included arachidonic acid from the omega-6 family, but over time it has been shown that it is synthesised by the body.

1. The role of vitamin F in the body
2. Sources and properties of vitamin F
3. The action of vitamin F
4. Omega-3 acids from plants and fish

The role of vitamin F in the body

Essential fatty acids (EFAs) perform a number of basic and interrelated functions in the body. First and foremost, they are an important component of cell membranes, i.e. the structures surrounding every cell in the body. Their presence determines the elasticity and proper structure of these membranes, as well as the ability of cells to exchange substances and transmit signals. The proper proportion of EFAs in cell membranes promotes the proper functioning of tissues, including muscles, the nervous and immune systems, and supports metabolic processes within cells.

EFAs are also the starting point for the formation of many biologically active molecules that are involved in the regulation of blood vessels. These compounds affect the tension of the vessel walls, blood flow and processes related to blood clotting, which is important for the proper functioning of the cardiovascular system. At the same time, EFAs participate in the regulation of lipid metabolism, influencing the transport and utilisation of fats in the body.

Sources and properties of vitamin F

Where is it found?

EFAs (vitamin F) are found in food, primarily in plant products, and often both acids are present in one product, although usually one of them clearly dominates. Products particularly rich in linoleic acid include sunflower oil, corn oil, grape seed oil, soybean oil, pumpkin seeds and sesame seeds. Alpha-linolenic acid is found in the highest amounts in flaxseed and flaxseed oil, chia seeds, walnuts and rapeseed oil. Rapeseed oil, soybean oil and walnuts are examples of products that provide both EFAs, although in different proportions.

"ALA-based supplements are typically used around training to support the use of carbohydrates for energy, which is intended to increase the effectiveness of the meal consumed." Tomasz Maciołek - Physiotherapist and Trainer

Form

From the point of view of their physicochemical properties, EFAs belong to fats that are liquid at room temperature, which is due to the presence of unsaturated bonds in their structure. However, these same bonds make these acids particularly sensitive to oxygen, light and high temperatures. Under their influence, oxidation processes easily occur, leading to a deterioration in the quality of the fat, changes in taste and smell, and a reduction in its nutritional value.

Consumption and storage

Oils rich in ALA, such as linseed oil or chia seed oil, are best used exclusively cold, as an addition to salads, spreads, cottage cheese or ready-made dishes, after heat treatment. Storing them in dark bottles in a cool place is also important for preserving their properties. Oils with a predominance of linoleic acid, despite being slightly more stable, are also not suitable for frying at high temperatures or for prolonged heat treatment.

The action of vitamin F

The most consistently reported benefits relate to the cardiovascular system and lipid profile, but it is important to understand that ‘increased supply’ can mean different things: sometimes it means replacing saturated fats (e.g. from fatty meats, butter, cheese) with vegetable fats richer in LA and ALA, and sometimes it is simply about adding another source of these acids without changing the rest of the diet. In the latter case, some benefits may not be observed, as energy requirements may be exceeded. This is because fatty acids provide 9 kilocalories (kcal) per 1 g.

Heart and circulatory system

Long-term studies of linoleic acid have shown that people who consume more of it have a lower average risk of coronary heart disease. This pattern was particularly evident when higher LA intake was associated with lower saturated fat intake, i.e. when LA actually ‘replaced’ another type of fat in the diet. In summary of mortality observations, higher LA intake and higher LA levels in biological markers were associated with a statistically lower risk of overall mortality and cardiovascular mortality.

Skin and epithelium

From the point of view of physiology, EFAs, referred to as vitamin F, are also important for the skin and epithelial tissues. They are an essential component of the skin barrier, affecting its tightness, hydration and ability to protect against external factors. Increasing their supply helps to maintain the proper lipid structure of the epidermis, which translates into better skin condition, especially in situations where the diet was previously low in vegetable fats.

Commonly available sources of vitamin F

Omega-3 acids from plants and fish

Alpha-linolenic acid (ALA) and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) belong to the same family of omega-3 fatty acids, but differ in structure, sources and how they work in the body. ALA is a plant form of omega-3 that the body cannot produce. EPA and DHA, on the other hand, are fatty acids with longer chains and a greater number of unsaturated bonds, and their main sources are fatty sea fish and fish oils. Although the body can produce them, the demand for them is so high that fish and seafood should not be omitted from the diet.

ALA in the body can be converted to EPA and then to DHA. However, this process occurs to a limited extent, and yet EPA and DHA are considered to be more biologically active. Although this division is very simplified, EPA is believed to be particularly associated with the regulation of inflammatory processes and the functioning of the circulatory system, while DHA plays an important role in the structure of cell membranes in the nervous system and the retina of the eye.

Sources:

• Farvid, M. S., Ding, M., Pan, A., Sun, Q., Chiuve, S. E., Steffen, L. M., Willett, W. C., & Hu, F. B. (2014). Dietary linoleic acid and risk of coronary heart disease: a systematic review and meta-analysis of prospective cohort studies. Circulation, 130(18), 1568–1578. https://doi.org/10.1161/CIRCULATIONAHA.114.010236
• Li, J., Guasch-Ferré, M., Li, Y., & Hu, F. B. (2020). Dietary intake and biomarkers of linoleic acid and mortality: systematic review and meta-analysis of prospective cohort studies. The American journal of clinical nutrition, 112(1), 150–167. https://doi.org/10.1093/ajcn/nqz349
• Wang, Q., Zhang, H., Jin, Q., & Wang, X. (2023). Effects of Dietary Linoleic Acid on Blood Lipid Profiles: A Systematic Review and Meta-Analysis of 40 Randomized Controlled Trials. Foods (Basel, Switzerland), 12(11), 2129. https://doi.org/10.3390/foods12112129
• Sadeghi, R., Norouzzadeh, M., HasanRashedi, M., Jamshidi, S., Ahmadirad, H., Alemrajabi, M., Vafa, M., & Teymoori, F. (2025). Dietary and circulating omega-6 fatty acids and their impact on cardiovascular disease, cancer risk, and mortality: a global meta-analysis of 150 cohorts and meta-regression. Journal of translational medicine, 23(1), 314. https://doi.org/10.1186/s12967-025-06336-2