Minerals & Vitamins
Vitamin A ~for more than your eyes
Vitamin A ~for more than your eyes
By Tammera J. Karr, MSHN, CNC, CNW, CNH 2009
In his 1919 book, Eat and Be Healthy, Virgil MacMickle, M.D., of Portland, Ore., recognized how crucial nutrition was for health. He wrote that the “chemical substances of which the body is composed are very similar to those of the foods which nourish it. They are made up of the same chemical elements….the body can only get the materials from which it is made in the first place from foods…” There are 13 known vitamins of which four are fat-soluble, and the remaining nine are water-soluble. A fat-soluble vitamin is absorbed with the help of fat. Vitamins A,D,E and K are fat-soluble.
|In his 1919 book, Eat and Be Healthy, Virgil MacMickle, M.D., of Portland, Ore., recognized how crucial nutrition was for health. He wrote that the “chemical substances of which the body is composed are very similar to those of the foods which nourish it. They are made up of the same chemical elements….the body can only get the materials from which it is made in the first place from foods…” There are 13 known vitamins of which four are fat-soluble, and the remaining nine are water-soluble. A fat-soluble vitamin is absorbed with the help of fat. Vitamins A,D,E and K are fat-soluble. |
A little history
3500 years ago, the ancient Egyptians recognized that night blindness (caused by a lack of vitamin A) could be treated with specific foods. Native Alaskan Indians made a point of eating the eyes from the fish and animals they hunted, believing they would keep the eyes of the hunter and his family healthy.
In 1913, attention turned to finding and isolating the vitamins themselves. The actual discovery of vitamin A is credited to a researcher named E. V. McCollum. He was curious why cows fed wheat did not thrive, became blind and gave birth to dead calves, while those fed yellow corn had no health problems. Thomas Osborne and Lafayette Mendel showed in rat experiments conducted at Yale University that butter contained a growth-promoting factor necessary for development. Soon known as fat-soluble vitamin A, its chemical character was established in 1933, and it was synthesized in 1947. Weston A. Price, discovered the diets of healthy traditional peoples contained at least ten times as much vitamin A as the American diet of his day (1939). Weston Prices work revealed vitamin A is one of several fat-soluble activators present only in animal fats and necessary for the assimilation of minerals in the diet.
More than your eyes
Many have been lead to believe the best way to get your vitamin A is thought beta-carotene. While it is true that many vegetables are loaded with health promoting carotenoids it should be noted, not everyone can increase or correct a vitamin A deficiency with plant based foods. There are several conditions that interfere with the conversion of carotenes in plant foods to vitamin A: being an infant or child, diabetes, low thyroid function, low fat diet, diarrhea, celiac or gluten sensitivity, and pancreatic disease.
Naturally occurring vitamin A is necessary for; anemia (due to vitamin A enhancing the absorption of Iron), heart disease, blood clotting- stroke, hemorrhoids, loss of appetite, celiac, colitis, crohn’s, gastric, heartburn, peptic ulcers, ulcerative colitis, deafness, tinnitus, urinary tract infections, macular degeneration, blurred vision, dry eye, general eye health and the list goes on….
The Merck Manual describes vitamin-A toxicity. Acute vitamin-A poisoning can occur in children after taking a single dose of synthetic vitamin A in the range of 300,000 IU or a daily dosage of 60,000 IU for a few weeks. In adults, vitamin-A toxicity has been reported in arctic explorers who developed drowsiness, irritability, headaches and vomiting, with subsequent peeling of the skin, within a few hours of ingesting several million units of vitamin A from polar bear or seal liver. Symptoms cleared up with discontinuation of the vitamin-A rich food. Vitamin A toxicity is much more common with the use of megavitamin tablets containing synthetic vitamin A. . . acute toxicity, 100,000 IU synthetic vitamin-A per day taken for many months.
Listed are approximate levels of vitamin A in common foods, in IUs per 100 grams:
Regular cod liver oil 100,000
Duck liver 40,000
Beef liver 35,000
Goose liver 31,000
Liverwurst sausage (pork) 28,000
Lamb liver 25,000
The US Recommended Daily Allowance of vitamin A is currently 5,000 IU per day. From the work of Weston Price, we know the amount in primitive diets was about 50,000 IU per day, if you consume generous amounts of whole milk, cream, butter and eggs from pastured animals; beef or duck liver several times per week; and 1 tablespoon regular cod liver oil or 1/2 tablespoon high-vitamin cod liver oil per day you can come close.
Some individuals may choose to use only supplementation, if so be sure of the quality of your supplement, read the label and know that the best also has a hefty price. If you like liver contact a local farmer who raises grass feed animals and get your liver from them. If you hate the flavor of liver contact me and I will tell you a trick in preperation.
Happy Turkey day complete with giblets!