The last time we were here, we covered the B vitamins. Today, we'll discuss vitamins C, D and E. Enough small talk, let's get down to business.
VITAMIN C
Vitamin C is a very reactive vitamin. It is one of the most versatile in the body, and the most unstable in food. It is convertible in different forms, and as a water soluble compound is excreted rapidly when excessive amounts are taken.
It is important in maintaining and forming the protein collagen, an essential part of the connective tissue which binds the body's cells together. Bones and teeth continually need vitamin C to repair their connective tissues; cuts and burns cannot heal without well-formed collagen. It also keeps capillaries and other blood vessels strong.
Vitamin C is also involved in the metabolism of several amino acids(proteins) and the precursor hormones epinephrine and norepinephrine. It is needed for the synthesis of thyroxin, which regulates metabolism. Extreme stress can increase the need for vitamin C as well.
A sever deficiency can result in scurvy, which is how the vitamin was discovered and named. Ascorbic acid was derived from the anti-scorbutic (anti-scurvy) factor.
The primary sources are fresh vegetables and fruits, especially citrus fruits.
VITAMIN D
Vitamin D regulates the metabolism of calcium and phosphorus, and promotes the growth of strong bones. It is essential for increasing the absorption of calcium into our bodies.
This is an unusual nutrient in that most of the body's intake is not from food, but rather from the action of sunlight (ultraviolet radiation) forming the nutrient in the skin. Given enough sun, a person doesn't need to consume any vitamin D. The few foods that do contain vitamin D have been fortified.
Rickets is the name of the disease caused by vitamin D deficiency, and it is most dramatically seen in growing children... with bowed legs and misformed ribs.
Fortifying milk with vitamin D has largely solved the problems of any deficiency. It should be noted that the safe range for vitamin D is fairly small, and too much taken in the form of supplements can be toxic to the system. This cannot happen from "D" formed from sunlight, because the body controls the amount formed.
Vitamin D is a fat-soluble vitamin, and it appears that the body can store enough during warm weather to last through the winter if necessary. This ability to store the vitamin is also why too much from supplements can be toxic.
Good sources of vitamin D include eggs, liver and some fish. Also, milk and cheeses are fortified with it.
VITAMIN E
Vitamin E acts as an anti-oxidant to prevent cell-membrane damage. In other words, it is a scavenger for destructive substances that would react against the unsaturated fats in the body. It also acts to detoxify radicals (kind of a good word for destructive substances) that occur elsewhere. It aids in the growth of good tissue and the healing of tissue from surgery and burns. We actually know more about vitamin E deficiencies in animals than we do in humans, and the deficiencies may not always translate to humans. However, if vitamin E in the bloodstream falls too low, the red blood cells tend to break open and cause a form of anemia. There is also evidence that environmental conditions like air pollution may increase human need for this vitamin.
Vitamin E is present in good quantity in whole grains, but is readily destroyed by processing. Milling of grains takes out a high percentage, and bleaching of flour takes the rest out. Refining of vegetable oil reduces about 25% of its vitamin E content. If protected from light, the losses are fairly small during the first 4 to 6 weeks of storage.
Some even tout vitamin E as slight aphrodisiac.
It is found in good quantity in grains, before processing, and in foods that are high in unsaturated fats, such as unrefined vegetable oils. There is more vitamin E in mature plants and in dark vegetables than in root vegetables and pale-colored fruits.
A good program wouldn't be complete without a good multivitamin. Join us next issue while we get back to the basics of a good workout plan. Until then, stay pumped, stay motivated and OO-RAH!
Semper Fi!
