VITAMIN A is absolutely essential for the ability to see. Stressors, such as too much reading, computer work, long driving, and poor lighting, exhaust our stores of this vitamin. The need for glasses or contacts usually arises within a few years of when children start going to school.
This vitamin also plays an important role in cell differentiation via the regulation of gene expression. Every cell in the body contains all of the DNA. However, each type of cell uses only a certain part of it to do its job. Vit A assists the cells in doing so. Because of its role in the turning on and off of the genes, Vit A supports the proper development of body structures in the fetus, such as the limbs, heart, as well as the eyes and ears.
Vit A helps to protect us from infections because it participates in the development and differentiation of white blood cells (lymphocytes). Moreover, it helps to activate (mobilize) them to do battle with pathogens and toxins that enter the body.
Vitamin A promotes healthy cells of the skin, and the mucosal lining of the respiratory and the digestive tracts. The skin and mucosa are the first line of defense in the body, creating a barrier to pathogens such as bacteria, viruses, and parasites. Any break in the surface of the skin, for example, allows these critters to enter our bodies and wreak havoc with it.
Smoking and exposure to cigarette or cigar smoke, as well as working in mines, around chemicals, or smoke, may damage the lining of the respiratory tract, leaving it vulnerable to infections such as bronchitis and pneumonia. Further, repeated or long-term exposure to these toxins may result in chronic inflammation of the tissue and eventual scarring, resulting in diseases such as asthma and emphysema.
Vitamin A helps to ward off and/or reverse iron-deficiency anemia by facilitating the release of iron from storage sites to be incorporated in the hemoglobin of red blood cells. Hemoglobin helps to carry oxygen to all cells in the body.
Vitamin A deficiency is quite common due to a deficient diet, and many environmental toxins. In third world countries, Vit A deficiency is the leading cause of blindness from xerophthalmia (dry eye). This condition results from changes in the cells of the cornea, which becomes ulcerated and scarred, leading eventually to blindness. Groups of small white bumps (Bitot’s spots) may also be seen on the sclera ( the white around the eye). Such extreme vitamin deficiency is not common in the western world. However, milder forms of deficiency are, potentially leading to night blindness and Bitot’s spots, the precursors to xerophthalmia.
People with a deficiency in this vitamin are more susceptible to colds, the flu, and infections of the digestive tract. Furthermore, a Vit A deficiency during pregnancy may lead to birth defects. It is important to note that Vit A excess during pregnancy may also result in birth defects. Vit A (like Vitamins D, E, and K) is a fat soluble vitamin that the body stores in the fat cells when exceeding the body’s daily needs. Over time, this may cause an excess in Vit A.