Vitamins F, essential fatty acids are composed of two fatty acids - linoleic acid (LA) and alpha-linoleic acid (LNA) - with linoleic acid being the most complete fatty acid. There are two basic categories of EFA's (essential fatty acids) - omega-3 and omega-6 which include linoleic acid and gamma-linoleic acid. The body is not capable of manufacturing essential fatty acids, while the fatty acid arachidonic acid can be synthesized in the body from linoleic acid.

Fatty acids are needed for normal growth and behavior and helps with healthy cell membranes, a well balanced hormone level and properly working immune system. 

They are essential for the synthesis of tissue lipids, play an important role in the regulation of cholesterol levels, and are precursors of prostaglandins, hormone like compounds producing various metabolic effects in tissues. 

To the skin, it brings suppleness and a youthful appearance and hair becomes more shiny and healthy when in good supply. It also seems important in the manufacture of sex and adrenal hormones. Fatty acids also stimulated the growth of the beneficial intestinal bacteria. Edema has also been reported with fatty acids in short supply. 

Arthritis is said to benefit from these fatty acids and they also aid in the transmission of nerve impulses and a shortage may lead to learning disabilities and a problem with recalling information.

deficiency indications 

Hair loss and eczema may be indicated when deficient and cause damage to the kidneys, heart and liver. Behavioral disturbances are also noted when deficient. The immune system can become less efficient with resultant slow healing and susceptibility to infections. 

Tear glands can also not work effectively and may dry up. Blood pressure and cholesterol levels may be higher when deficient and blood more likely to form clots.

extra needed when and if 

People that are overweight, have dry eyes, bruise easily and have frequent infections may consider increasing their intake as well as those on a low fat diet or with a dry skin, dandruff or brittle nails.

food sources 

They are available in the evening primrose oil, grape seed oil, flaxseed oil, and oils of grains, nuts and seeds, such as soybean, walnuts, sesame, and sunflower. It is also present in avocados, as well as meat and fish like salmon, trout, mackerel and tuna. 

Omega-6 EFA is found in raw nuts, seeds, legumes, grape seed oil and flaxseed oil. Omega-3 EFA is found in fish, canola oil, and walnut oil.