Most vitamins are described as either fat-soluble or water-soluble. The simple mnemonic "ADEK" is used to identify the fat-soluble vitamins: vitamins A, D, E and K. Fat-soluble vitamins are stored by the body, in our stores of fat and in our livers, whereas a larger proportion of the water-soluble vitamins we consume pass through our bodies and are excreted in urine.
Any vitamins can be toxic if taken in massively large doses, but the fat-soluble vitamins need to be taken more carefully because of their penchant for building up in our systems. Fat-soluble vitamins are less likely to need to be taken in supplemental form because the body stores them. Also, unlike the water-soluble vitamins, the fat-soluble vitamins do not lose their vitamin content in cooking and preparation.
We are all familiar with the term "RDA"-recommended daily allowance-that is used for vitamins and is found on many vitamin labels and food packages. However, you should also look for the "UL"-upper intake level-to make sure you do not take too much of your vitamins, especially the ones that are fat-soluble.
The description of different vitamins as fat-soluble or water-soluble doesn't refer to the form they come in. It doesn't mean that one kind of vitamins dissolves in water and one doesn't. The terms refer to the way our bodies handle the vitamins. Fat-soluble vitamins are absorbed through our stomachs and intestines and are stored in the liver, while water-soluble vitamins dissolve and are absorbed for immediate use. People are less likely to be deficient in fat-soluble vitamins because our bodies store them, but certain conditions and medications can cause deficiencies in any vitamin. When in doubt, consult your doctor.
