Here I begin a four-part series on the first alphabetical nutrient: vitamin A. Let’s take a look at the straight facts around this essential nutrient, what it does in our bodies, and how its discovery had everything to do with our eyesight.
Hippocrates, the famous Greek doctor, first recognized night blindness sometime around 300 BC. He recommended eating raw liver as a cure for the condition. Another eye disease, “xerophthalmia” (dry cornea and conjunctiva), was thought to be related because of a nutritional deficiency that was corrected by cod liver oil.
In 1917, a German researcher was successful in reversing both of these eye conditions in malnourished children with a diet including whole milk or butter. Through the intensive research conducted later, “fat-soluble vitamin A” was identified. A Nobel Prize was distributed to one physician, Dr. Wald, who in 1964 found that the retina contains vitamin A. And that vitamin A comes from carotenoids in fruits and vegetables.
Vitamin A isn’t one nutrient; instead, it is a general term for many chemicals. Retinoids consist of retinal, retinol, retinoic acid, and related chemicals. Provitamin A carotenoids include beta-carotene and other carotenoids, which our body can convert into retinal. Among the many hundreds of carotenoid made by plants, only 10% are considered to be provitamin-A carotenoids, the ones that are turned into vitamin A in our bodies.
RECOMMENDED: Vitamins That You Need to Help Your Immunity
Vitamin A’s important roles in our bodies include:
2. Development: Essential for the development and formation of ears, eyes, heart, brain and limb
3. Red Blood Cells: Helps move iron from storage to red blood cells, which carry oxygen in the body
4. Immune Function: Essential for normal immune function, maintaining the body’s first line of defense (skin, mucus lining of airways, urinary system), and for development of white blood cells
5. Gene Expression: Vitamin A helps prevent cancer by inducing tumor suppressor genes called “retinoic acid receptors” (RAR).