Do not take with meals or supplements that contain large amounts of pectin , a type of soluble fiber found in citrus fruits. Cigarette smokers, alcoholics, and people who eat fewer than three servings a day of fruits or vegetables. Vitamin A fortified milk and milk products, such as cheese, cream, and butter, and fortified margarine. There is evidence that it causes lung cancer in smokers taking 50,000 IU in supplement form. Do not take preformed vitamin A supplements unless you are under a doctor s supervision.
Symptoms slowly disappear once the dosage is reduced.
Do not take more than 5,000 IU if you are pregnant or trying to conceive. Vitamin A also has another basic function. It acts as a kind of traffic cop for cells in a developing embryo. As the cells start to divide and multiply, vitamin A helps guide them in the direction they need to go, putting this one on its way to becoming a muscle cell, steering another one toward becoming a liver cell, and so on. Vitamin A helps maintain the surfaces of the skin, the mucous membranes lining the nose and throat, and the tissues lining the intestines, bladder, and other internal cavities.