By Mary Ellen Posthauer, RDN, CD, LD, FAND
Fat-soluble vitamins A, E, and K dissolve in fat and are transported in the body attached to lipids and require pancreatic enzymes and bile for absorption. They are stored in the liver and fatty tissue, which is why an excess concentration of fat-soluble vitamins can be toxic. When blood concentrations of fat-soluble vitamins decline, the body simply retrieves them from storage. Individuals with pancreatic insufficiency, cirrhosis or malabsorption syndrome may have low concentrations of fat-soluble vitamins. Consuming sources of fat-soluble vitamins daily is not necessary, but average intake of these vitamins consumed over time is beneficial. The impact of these fat-soluble vitamins in the management of wounds and other conditions will be discussed.
Vitamin A was the first fat-soluble vitamin recognized. It plays a key role in normal vision, protein synthesis, and, most important, maintaining the health of epithelial cells on the surface of the skin and the mucous membranes. Beta-carotene, which is a vitamin A precursor made by plants and stored in human fat tissue, is an effective antioxidant. Antioxidants protect other compounds from attack by oxygen, avoiding cell damage or impairment of cell function. Vitamin A prevents or reverses the negative effects of glucocorticoids, which may impair or delay wound healing. However, there is not evidence to support the practice that taking mega doses of vitamin A has a positive effect on would healing when you are taking steroids. Taking large doses of vitamin A with medications that effect the liver increases the risk of liver damage, such as some anticonvulsants and hyperlipidemics.
Individuals should always consult their physician and/or pharmacist for any food/drug interactions prior to starting a new medication. The Tolerable Upper Limit (UL), which is the highest level of intake that is likely to pose no harm, is 10,000 units (3000 micrograms). The UL is for preformed vitamin A and does not include provitmain A carotenoids. Deep green and yellow fruits and vegetables are rich sources of beta-carotene. Milk, cheese, butter and liver provide preformed vitamin A.
Vitamin E acts as an antioxidant, protecting lipids and cell membranes, in particular the lungs where cells are exposed to high concentrations of oxygen. It is responsible for collagen synthesis and fat metabolism. High doses of vitamin E have an adverse effect on anticoagulant medication by enhancing the action of the medication, which could lead to hemorrhage. The UL for Vitamin E is 1,000 milligrams per day. Good sources of this vitamin are meats, poultry, almonds vegetable oils and peanut butter.
Vitamin K is essential for the activation of several proteins, including prothrombin—the precursor of thrombin responsible for blood clotting. Bacteria in the intestinal tract can synthesize Vitamin K. Antibiotics can destroy the vitamin K-producing bacteria in the intestine, reducing the supply required for normal coagulation. Consuming a high amount of vitamin K rich foods, such as green leafy vegetables, broccoli and brussel sprouts, reduces the effectiveness of anticoagulant medications. Eating a consistent amount of vitamin K rich foods from day to day reduces the risk of food/medication interaction.
When food intake is deficient in the fruits and vegetables or intake is poor, a multivitamin should be considered. Oral nutritional supplements and fortified foods also contribute to the daily intake of fat-soluble vitamins. Food first before supplements should be the primary consideration for any nutrition intervention in the management of wound patients.
About The Author
Mary Ellen Posthauer RDN, CD, LD, FAND is an award winning dietitian, consultant for MEP Healthcare Dietary Services, published author, and member of the Purdue University Hall of Fame, Department of Foods and Nutrition, having held positions on numerous boards and panels including the National Pressure Ulcer Panel and the American Dietetic Association’s Unintentional Weight Loss work group.
The views and opinions expressed in this blog are solely those of the author, and do not represent the views of WoundSource, Kestrel Health Information, Inc., its affiliates, or subsidiary companies.