Fish oil is obtained from the liver of fresh fish, such as Atlantic cod or shark, as well as from marine mammals – whales and seals. These fish and marine mammals live in cold waters, have strong tissues and accumulate a huge amount of nutrients.
Fish oil has long been used in the fight against rickets, cachexia, rheumatic diseases, problems of a dermatological nature and was even fuel for lamps. It was used for tanning leather, preserving boards, and wooden elements.
This oily substance was forced to drink in childhood, and it seemed very disgusting. In the 60s of the last century, fish oil in liquid form was mandatory introduced into the diet of children in kindergartens. Today it is a dietary supplement and, fortunately, it can be taken in capsules.
Fish oil, despite the fact that it is not very pleasant to the taste, is a rich source of unsaturated fatty acids, omega-3 and omega-6, and a vitamin bomb from groups A, D and E.
It affects the proper functioning of the body, strengthens its immunity, and activates the brain.
Properties of Fish Oil
Strengthening the immune system.
Fish oil contains valuable fatty acids: omega-3 and omega-6, which support the production of hormones with an anti-inflammatory effect and optimize the immune system. Vitamin A supports the regeneration of the mucous membranes, and is also a barrier to pathogenic microorganisms. 
Omega-3 fatty acids improve the functioning of the brain.  They improve the movement of nerve stimuli from gray to white matter, and also affect the improvement of blood supply to the brain. Therefore, fish oil is especially recommended for children, as it supports their development, improves memory and concentration. It can also minimize the risk of developing Alzheimer's disease and dementia in the elderly. 
Support of the cardiovascular system.
Fat, or rather the fatty acids contained in it, reduce the content of bad LDL cholesterol in the blood and lead to an increase in the content of good HDL cholesterol. All this ultimately leads to the regulation of hypertension, dilutes the blood and reduces the formation of blood clots, prevention of cardiac arrhythmia, which minimizes the risk of atherosclerosis and coronary heart disease. 
In addition to fatty acids, the content of vitamin E plays an important role for the body. It strengthens the walls of veins and arteries and is a protection for red blood cells, prolonging their life. Vitamin E prevents cardiovascular diseases, slows down the aging process of the skin and the entire body.
Fish oil can prevent weight loss during chemotherapy, as well as prevent the loss of muscle mass in people with lung cancer.  Omega-3 fatty acids and alkylglycerols, alkoxyglycerols and squalene contained in fat minimize the risk of developing breast, ovarian and intestinal cancer. According to recent studies, the consumption of fish oil can also reduce the size and number of tumors, as well as minimize their tendency to metastasis. 
Prevention of eye diseases.
Vitamin A, which is one of the components of fish oil, has a beneficial effect on the organ of vision. It prevents various eye diseases, including macular degeneration, a serious disease that can even lead to complete loss of vision. It also prevents chicken blindness, problems with proper hydration of the conjunctiva, and corneal ulcers. Omega-3 acids are a component of the retina, so their intake is especially important for pregnant women and children. 
Strengthening of the bone and muscle system.
Vitamin D promotes the absorption and assimilation of calcium and phosphorus, increases the number and strength of muscle cells, is responsible for the entire economy of calcium and phosphates and improves the mineralization of bones and teeth. Fish oil regenerates tissues, its appropriate doses are recommended for the prevention and treatment of diseases such as rickets or osteoporosis. Fish oil also relieves rheumatic pains. 
Nourishing properties for skin, hair and nails.
Fish oil has a nourishing effect on the skin: it moisturizes it, prevents keratinization and dryness. In addition, in the form of an ointment, it promotes the healing of wounds, ulcers, bedsores and frostbite. All this is due to the content of vitamin A, which is a strong antioxidant that destroys free radicals and the content of vitamin D, which reduces skin inflammation. 
The Use of Fish Oil
Approximately 2 capsules of fish oil per day cover the body's daily need for vitamin A and D3.
The dosage of fish oil is closely related to the concentration of acids present in this additive, so it is especially important to follow the manufacturer's instructions on the package. It is recommended to use from early autumn to late spring, in doses of 2 capsules 2 times a day for adults. Fish oil is best consumed during a meal, which will help neutralize its unpleasant taste.
Choose a product in capsules that has a longer shelf life and does not oxidize, and also has fewer storage requirements.
Contraindications and side effects when using fish oil.
Fish oil, though, and has many valuable medicinal properties, it is impossible to accept:
people suffering from hypercalcemia and kidney stones
people who use supplements containing vitamin a or D
people taking anticoagulants
people staying in a very Sunny place (can lead to pigmentation of the skin)
people who are treated with antibiotics.
Especially careful in taking fish oil should be people suffering from sarcoidosis and pregnant women (excess fish oil can damage the fetus).
Fish oil should always be taken in accordance with the instructions and recommendations indicated on the package.
Fish oil in excessive amounts can lead to side effects:
an overdose of vitamin A or D will lead to hypervitaminosis, the main symptoms of which are:
lack of appetite
increased desire to urinate
enlarged liver and spleen
Recommendations for the use of fish oil.
Fish oil, with the above exceptions, is recommended for almost everyone. But especially:
children and adolescents during puberty
the weakened, old, sick or in the process of treatment
people exposed to stressful factors
people who abuse alcohol
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