Fat-soluble vitamins, unlike their water-soluble counterparts, stay stored in the body. These vitamins are absorbed by lipids (fat) in the intestinal tract, and can stay stored in the body tissues and the liver. There are a number of ways to make sure your body gets the proper amount of these vital, fat-soluble vitamins without overdosing on them.
What Vitamins are Fat-Soluble?
According to Colorado State University's Extension (diet and nutrition) website, there are four fat-soluble vitamins: A, D, E and K. In order to maintain a healthy immune system and body, these vitamins and their nine water-soluble counterparts are a daily necessity. Vitamin A is responsible for healthy skin and mucus production, vitamin D for calcification of bones, E helps buffer and protect vitamins A and C, and is full of antioxidants that fight free radicals, and vitamin K is responsible for healthy blood clotting.
Where Are Fat-Soluble Vitamins Found Naturally?
While a balanced diet full of leafy greens, fruits and vegetables rich in antioxidants, lean meats and fish should provide an adequate amount of these vitamins, taking a daily multivitamin should help make up any deficiencies.
Your daily intake of dietary fat should help dissolve and absorb these vitamins easily, but if you are vegetarian or vegan then it is extremely important for you to monitor your dietary fat and vitamin intake and make sure you are getting your required amounts of fat- and water-soluble vitamins. Vegans, especially, need to be careful to avoid severe malnutrition and vitamin deficiency because of dietary restrictions.
Dangers of Overdose
The American Academy of Family Physicians says large doses of fat-soluble vitamins are never recommended, because the body takes a longer amount of time to excrete them. If you are taking megadoses of any fat-soluble vitamin, you risk overloading the body and poisoning the organ systems, which could potentially cause organ failure and other severe complications. Overdosing on vitamin A not only causes problems to your body, but can cause birth defects in your children, an overdose of vitamin D, ironically, can cause bone softening, and kidney problems. Vitamin E overdose doesn't appear to have a solid problem tied to it, but studies suggest it can contribute to congestive heart failure. As for vitamin K, while it promotes healthy blood clotting in regulated doses, megadoses can cause blood cells to burst and excessive bleeding.
Taking Fat-Soluble Supplements
If you are not getting enough fat-soluble vitamins in your daily diet, a multivitamin can make up for any deficiencies. The best way to take any kind of fat-soluble supplement is with food. Your body will not be able to dissolve or absorb the vitamin otherwise. A glass of low-fat milk, for example would provide an adequate amount of fat to help your body absorb the vitamin.
Who Is At Risk For Deficiency?
According to the National Institutes of Health, most people in developed nations are not at risk for deficiencies of fat-soluble vitamins, but there are a few who are susceptible to certain deficiencies. People who have had any kind of gastric surgery, for example, will find it harder to absorb fat-soluble nutrients, and should be careful of becoming vitamin deficient. Severely underweight babies also risk being vitamin deficient, but this includes water-soluble vitamins as well. People who live in climates where there is less sun can be at risk for Vitamin D deficiency, especially if they are dark skinned. An additional Vitamin D supplement should make up any potential deficiencies.
For the general population, a good diet and a multivitamin (with an additional Vitamin D supplement) should cover the daily recommended allowance, but consult a doctor and nutritionist to make sure you--or your infant--are deficient before you take extra supplements.