Vitamin F is not a vitamin in the traditional sense of the word.

Rather, vitamin F is a term for two fats — alpha-linolenic acid (ALA) and linoleic acid (LA). They are essential for regular body functions, including aspects of brain and heart health (1).

ALA is a member of the omega-3 fat family, while LA belongs to the omega-6 family. Common sources of both include vegetable oils, nuts, and seeds (2).

They were discovered in the 1920s when scientists found that fat-free diets had adverse effects on rats. Initially, the scientists suspected the rats were deficient in a new vitamin they called vitamin F — later found to be ALA and LA (3).

This article discusses vitamin F, including how it works, its potential health benefits, and which foods contain the highest amounts of it.

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The two types of fat that comprise vitamin F — ALA and LA — are classified as essential fatty acids, meaning they are necessary for health. Since your body is unable to make these fats, you have to get them from your diet (4).

ALA and LA play the following crucial roles in the body (5, 6):

  • Serve as a calorie source. As fats, ALA and LA provide 9 calories per gram.
  • Provide cell structure. ALA, LA, and other fats provide structure and flexibility to all cells in your body as a major component of their outer layer.
  • Aid growth and development. ALA plays an important role in normal growth, vision, and brain development.
  • Are converted to other fats. Your body converts ALA and LA into other fats needed for health.
  • Help make signaling compounds. ALA and LA are used to make signaling compounds that help regulate blood pressure, blood clotting, immune system responses, and other major body functions.

Vitamin F deficiency is rare. However, a lack of ALA and LA can lead to various symptoms, such as dry skin, hair loss, slow wound healing, poor growth in children, skin sores and scabs, and brain and vision problems (7, 8).

summary

Vitamin F supplies calories, provides structure to cells, supports growth and development, and is involved in major bodily functions like blood pressure regulation and immune response.

According to research, the fats that make up vitamin F — ALA and LA — may offer several unique health benefits.

Health benefits of alpha-linolenic acid

ALA is the primary fat in the omega-3 family, a group of fats thought to have many health benefits. In the body, ALA is converted into other beneficial omega-3 fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (9).

Together, ALA, EPA, and DHA offer a wealth of potential health benefits:

  • Reduce inflammation. An increased intake of omega-3 fats like ALA has been associated with decreased inflammation in the joints, digestive tract, lungs, and brain (10, 11).
  • Improve heart health. Though findings are mixed, increasing ALA in your diet may help lower your risk of heart disease. In one study, every 1-gram increase in ALA consumed per day was associated with a 10% reduced risk of heart disease (12).
  • Aid growth and development. Pregnant women need 1.4 grams of ALA per day to support fetal growth and development (13).
  • Support mental health. More research is needed, but some evidence suggests that regular intake of omega-3 fats may help improve symptoms of depression and anxiety (14, 15).

Health benefits of linoleic acid

Linoleic acid (LA) is a primary fat in the omega-6 family. Like ALA, LA is converted into other fats in your body.

It offers many potential health benefits when consumed in moderation, especially when used in place of less healthy saturated fats (16):

  • May reduce the risk of heart disease. In a study in over 300,000 adults, consuming LA in place of saturated fat was associated with a 21% reduced risk of death related to heart disease (17).
  • May reduce the risk of type 2 diabetes. One study in more than 200,000 people found that LA was associated with a 14% reduced risk of type 2 diabetes when consumed in place of saturated fat (18).
  • May improve blood sugar control. Several studies suggest LA may aid blood sugar control when consumed in place of saturated fats (19).
summary

Diets containing ALA may help reduce inflammation, promote heart and mental health, and support growth and development. Furthermore, LA may aid blood sugar control and has been associated with a reduced risk of heart disease and type 2 diabetes.

To optimize the benefits of vitamin F, maintaining a healthy ratio of LA to ALA in your diet may be key.

This is due to the opposing signals these fats send in the body. While LA and other omega-6 fats tend to induce inflammation, ALA and other omega-3 fats work to inhibit it (20).

Some experts estimate that the ratio of omega-6 to omega-3 fats in Western diets may be as high as 20:1. According to studies, this may contribute to inflammation and an increased risk of heart disease (21).

Though an ideal ratio has yet to be determined, a popular recommendation is to maintain the ratio at or below 4:1 (22).

However, instead of abiding by a ratio, it may be simpler to follow recommendations from the Institute of Medicine (IOM). These suggest adults consume 1.1–1.6 grams of ALA and 11–16 grams of LA per day (23).

summary

Some experts suggest that adults consume a 4:1 ratio of LA to ALA, or 11–16 grams of LA and 1.1–1.6 grams of ALA, per day to reap the greatest benefit from vitamin F fats.

Vitamin F supplements are unnecessary if you consume a wide variety of foods containing ALA and LA.

Though most food sources typically contain both, many carry a higher proportion of one fat than the other.

Here are the amounts of LA in some common food sources:

  • soybean oil: 7 grams of LA per tablespoon (15 ml) (24)
  • olive oil: 10 grams of LA per tablespoon (15 ml) (25)
  • corn oil: 7 grams of LA per tablespoon (15 ml) (26)
  • sunflower seeds: 11 grams of LA per ounce (28 grams) (27)
  • pecans: 6 grams of LA per ounce (28 grams) (28)
  • almonds: 3.5 grams of LA per ounce (28 grams) (29)

Many foods high in LA also contain ALA, albeit in lesser amounts. However, particularly high proportions of ALA can be found in:

  • flaxseed oil: 7 grams of ALA per tablespoon (15 ml) (30)
  • flax seeds: 6.5 grams of ALA per ounce (28 grams) (31)
  • chia seeds: 5 grams of ALA per ounce (28 grams) (32)
  • hemp seeds: 3 grams of ALA per ounce (28 grams) (33)
  • walnuts: 2.5 grams of ALA per ounce (28 grams) (34)

Animal products, such as fish, eggs, and grass-fed meat and dairy products, contribute some ALA and LA but are mainly high in other types of omega-6 and omega-3 fats (35).

summary

Both ALA and LA are found in plant oils, nuts, and seeds. They’re also found in some animal products, though in small amounts.

Vitamin F is comprised of two essential omega-3 and omega-6 fats — ALA and LA.

These two fats play a major role in regular bodily processes, including immune system function, blood pressure regulation, blood clotting, growth, and development.

Maintaining a 4:1 ratio of LA to ALA in your diet is often recommended to help optimize the potential benefits of vitamin F, which include improved blood sugar control and reduced inflammation and heart disease risk.

Consuming foods high in ALA, such as flax seeds, flaxseed oil, and chia seeds, is one way to help shift the balance in favor of positive health outcomes.