You need at least a small amount of fat in your diet to provide the essential omega-3 and omega-6 fatty acids your body can't make and to help with the absorption of fat-soluble vitamins. If you don't get at least 15 percent of your calories from fat, you could develop an essential fatty acid deficiency or a deficiency of one or more of the fat-soluble vitamins A, D, E and K. An essential fatty acid deficiency can be corrected by getting more omega-3 and omega-6 fats in your diet, and the combination of fat and fat-soluble vitamins can resolve fat-soluble vitamin deficiencies.
Fat-Soluble Vitamin Deficiencies
You can develop deficiencies of vitamins A, D, E and K if you don't get enough fat in your diet because your body can only absorb these nutrients in the presence of fat. Vitamin A deficiency symptoms can include dry skin, night blindness, increased susceptibility to infections and problems with bone and tooth development. Not absorbing enough vitamin D can cause soft and weak bones, and too little vitamin K can lead to increased bleeding.
You need the essential fatty acids for keeping your skin healthy, so not getting enough fat in your diet can cause skin problems. An essential fatty acid deficiency increases the loss of water from your skin, which results in a dry, scaly rash. This type of deficiency can also make it harder for your wounds to heal.
Two types of omega-3 fatty acids, eicosapentaenoic acid and docosahexaenoic acid, are essential for brain development. Not getting enough DHA may result in learning deficits and increase the risk for certain types of dementia, including Alzheimer's disease. The omega-6 fat arachidonic acid is also an important component of brain tissue.
EPA and DHA are also important components of the retina, so an essential fatty acid deficiency could affect your vision. DHA helps form the pigment rhodopsin, which you need for your brain to turn the light hitting your retina into the images you see. The retina can recycle and conserve DHA, however, so even low intakes of essential fatty acids may be enough to protect your vision. Getting enough omega-3 fats in your diet may help lower your risk for dry eyes and age-related macular degeneration, according to an article by optometrist Gary Heiting, O.D., on AllAboutVision.com.