Roles of Fat Soluble Vitamins

Certain vitamins---A, D, E and K---are labeled as fat-soluble. They are dissolved by lipids and travel through parts of the small intestines into the blood. The body absorbs them the same way that it absorbs fats. Fat-soluble vitamins are stored in the liver and fatty tissues because they do not need to be replaced in the body as quickly as other vitamins, such as B-complex and C, which are considered water-soluble.

Significance

Each fat-soluble vitamin, in a similar manner to minerals, has a different function in the body and can found in different foods, which is why a balanced diet is important. Fat-soluble vitamins maintain particular body parts, such as eyes, skin and hair, bones, blood and the small intestine.

Vitamin A

Vitamin A brings healthiness to eyes; the reproductive system; respiratory, urinary and intestinal tracts; and the immune system. Vitamin A also aids the skin and mucous membranes in fighting off bacteria and viruses. You find this fat-soluble vitamin in cheese, liver, whole milk, eggs, carrots, spinach, kale, cantaloupe, oatmeal, papaya, mango and vegetable soup.

Vitamin D

Vitamin D promotes bone growth; helps with the absorption of calcium; monitors calcium and phosphorous levels and immune responses; and prevents diseases such as osteoporosis and rickets. Vitamin D prevents bones from becoming brittle or misshapen. Foods that include vitamin D: milk, eggs, cheese, liver, salmon, tuna fish and sardines. Exposure to the sun's ultraviolet B rays also facilitates the production of Vitamin D.

Vitamin E

Vitamin E protects the body from free radicals, which are molecules that could damage cells by altering their chemical structure. This fat-soluble vitamin helps immune functions and regulates metabolic processes and cell development. You get Vitamin E from spinach, mango, kiwi, soybean, broccoli, dry roasted peanuts, sunflower seeds and almonds.

Vitamin K

Vitamin K works with the liver to ensure that blood clots correctly and produces proteins, such as prothrombin and proconvertin, that the blood needs to coagulate. Vitamin K is found in vegetables such as spinach, asparagus and celery, as well as in cheese, liver, green tea and coffee. The body's intestines also make vitamin K.

Prevention/Solution

Too little or too much of each fat-soluble vitamin may lead to health problems. For example, if you are deficient in vitamin A, you might wind up with blindness or osteoporosis. High levels of vitamin A, however, may lead to a higher risk of some cancers, such as lung cancer. The daily required amount of each vitamin depends on age. For example, a child who is 13 or younger needs 5 mcg (micrograms) of vitamin D a day, while an adult 71 years or older needs 15 mcg.