Benefits of Fat-Soluble Vitamins

Fresh vegetables are rich in vitamins A, E, and K, all vital nutrients for your body's proper functioning. These vitamins, along with vitamin D, are different from the C and B vitamins in that they are soluble only in fats, not in water.

This is termed "hydrophobic," Latin for "fearing water." Fat soluble vitamins are actually repelled by water molecules, and in the body must be dissolved in fats and absorbed by bile -- the substance designed to digest fats. This can become a problem in people who are on extremely low fat diets, or who take vitamin supplements on an empty stomach.

Fat soluble vitamins must have some fat when ingested in order to be properly absorbed by your digestive tract. If they pass too far through your digestive system, it becomes impossible for the body to absorb them, and even large doses of vitamin supplements will prove ineffective.

Both multivitamins with fat-soluble vitamins and vegetables rich in vitamins A and K (E is found primarily in vegetable oil) should be taken with some fats as well as plenty of water (to dissolve the B and C vitamins). This means if you expect to get full nutritive value from that salad, at least a spritz of fat-containing dressing needs to go on it.

For best effects, look for dressings that are made with olive oil, or that are fortified with omega-3 and omega-6 fatty acids; these healthy fats are needed by your body anyway.

Review of Fat Soluble Vitamins

The four main fat-soluble vitamins A, D, E, and K do not have to be taken daily; unlike most water-soluble vitamins, these vitamins are stored in the body's fat. If you only eat foods containing them once every few days, as long as you have taken enough at those times to carry you through several days you will be fine.

Unlike water-soluble vitamins, fat-soluble vitamins don't work in energy metabolism. Instead, they are necessary to support a wide variety of specific organs: the eyes, bones, teeth, gastrointestinal system, nervous system, skin, and blood.

It is easier to reach a toxic level of these vitamins because they are not flushed out of the body like water-soluble vitamins are. For this reason, vitamin supplements providing megadoses of these substances are not a good idea.