Vitamin F is an essential fatty acid found in evening primrose oil, grape seed oil, flax seed oil and oils of grains, nuts and seeds, such as soybean, walnuts, sesame and sunflower. It is present in avocados, as well as meat and fish such as salmon, trout, mackerel and tuna.
Vitamin F also is known as linoleic acid. There are two types of essential fatty acids — omega-3 and omega-6. Omega-6 EFA is found in raw nuts, seeds, legumes, grape seed oil and flax seed oil. Omega-3 EFA is found in fish, canola oil and walnut oil.
The human body is not capable of manufacturing essential fatty acids. But they are needed for normal cell growth and to maintain a healthy immune system.