Importance of Vitamin A
Vitamins are classified as either fat-soluble (dissolving in fat) or water-soluble (dissolving in water). Vitamin A is a fat-soluble vitamin because it dissolves in fat and is stored in body fat. It plays a role in many important functions of the body. Vitamin A is critical for vision. It also important for the health of mucous membranes such as those in the eyes, throat, nose and mouth. In addition, because vitamin A plays a role in cell growth, it is also needed for maintenance of the heart, lungs, kidneys and other organs.
Sources of Vitamin A
Vitamin A is found in two forms in foods. Retinol, or the active form of vitamin A, is found in liver, butter, whole milk, cheese and egg yolks. Because these foods are also high in saturated fat and cholesterol, they are not recommended to be the primary sources of vitamin A in your diet. The other form of vitamin A is a provitamin found in many fruits and vegetables. Provitamins are simply turned into the active form of vitamins by the body. Fruits and vegetables rich in vitamin A are typically orange, red or dark green in color. Good sources of vitamin A include spinach, carrots, cantaloupe, red and orange peppers, and broccoli. Other foods rich in vitamin A are ricotta cheese, and milk.
Because vitamin A is a fat-soluble vitamin, in order to be properly absorbed by the body it should be eaten with other foods that contain a small amount of fat. The vegetable sources of vitamin A may be eaten with salad dressing. Ricotta cheese and milk should be the low fat (1%) or part skim varieties, rather than fat-free for this reason.
Vitamin A deficiency
Vitamin A deficiency can develop after weight loss surgery due to low intake or difficulty absorbing the vitamin. Because vitamin A is a fat-soluble vitamin, low intakes of fat, decreased ability to absorb fat, or diarrhea can also contribute to low levels of vitamin A in the body after weight loss surgery.
Signs of Vitamin A Deficiency
Lab work completed after weight loss surgery will usually include a check of the vitamin A level in your blood. If it is found to be low, your doctor or dietitian will recommend a supplement. Signs of vitamin A deficiency include impairment in vision when in low light or darkness. Dry, scaly skin and mucous membranes may also be symptoms of vitamin A deficiency.
Vitamin A Toxicity
The potential for toxicity exists with vitamin A excess intake in the active form, found in liver and other animal sources and in supplements containing the retinol form. Vitamin A toxicity from food sources containing the provitamin form, found in fruits and vegetables, is not a health concern. Excessive intakes of foods or supplements containing the active or retinol form of vitamin A can lead to toxicity resulting in dizziness, nausea, skin irritation and other symptoms. It is recommended that pregnant women check with their health care provider before beginning vitamin A supplementation due to the potential for birth defects associated with excess vitamin A intake.
Maintaining Vitamin A Health
Choose fruits and vegetables high in vitamin A such as spinach, carrots, cantaloupe, red and orange peppers, and broccoli to maintain vitamin A health. A diet rich in vitamin A will add color, variety and fiber to your diet.