Linus Pauling (1901-1994), Nobel Prize winner, one of most influential chemist in history, also known as 'Vitamin C Man' will always be remembered as an 'authority' notably in vitamin c area/research.
This article is taken from Linus Pauling Institute, Oregon State University on the latest what scientists know about..VITAMIN C
Vitamin C, also known as ascorbic acid, is a water-soluble vitamin. Unlike most mammals, humans do not have the ability to make their own vitamin C. Therefore, we must obtain vitamin C through our diet.
Vitamin C is required for the synthesis of collagen, an important structural component of blood vessels, tendons, ligaments, and bone. Vitamin C also plays an important role in the synthesis of the neurotransmitter, norepinephrine. Neurotransmitters are critical to brain function and are known to affect mood. In addition, vitamin C is required for the synthesis of carnitine, a small molecule that is essential for the transport of fat to cellular organelles called mitochondria, for conversion to energy . Recent research also suggests that vitamin C is involved in the metabolism of cholesterol to bile acids, which may have implications for blood cholesterol levels and the incidence of gallstones .
Vitamin C is also a highly effective antioxidant. Even in small amounts vitamin C can protect indispensable molecules in the body, such as proteins, lipids (fats), carbohydrates, and nucleic acids (DNA and RNA) from damage by free radicals and reactive oxygen species that can be generated during normal metabolism as well as through exposure to toxins and pollutants (e.g. smoking). Vitamin C may also be able to regenerate other antioxidants such as vitamin E .
The Recommended Dietary Allowance (RDA)
In the U.S., the recommended dietary allowance (RDA) for vitamin C was recently revised upward from 60 mg daily for men and women. The RDA continues to be based primarily on the prevention of deficiency disease, rather than the prevention of chronic disease and the promotion of optimum health. The recommended intake for smokers is 35 mg/day higher than for nonsmokers, because smokers are under increased oxidative stress from the toxins in cigarette smoke and generally have lower blood levels of vitamin C.
The amount of vitamin C required to prevent chronic disease appears to be more than that required for prevention of scurvy. Much of the information regarding vitamin C and the prevention of chronic disease is based on prospective studies, in which vitamin C intake is assessed in large numbers of people who are followed over time to determine whether they develop specific chronic diseases.
Benefits in disease prevention
-A study found that the risk of death from cardiovascular diseases was 42% lower in men and 25% lower in women who consumed more than 50 mg/day of dietary vitamin C and who regularly took vitamin C supplements, corresponding to a total vitamin C intake of about 300 mg/day (NHANES I)
-A prospective study that followed more than 2,000 residents of a rural Japanese community for 20 years found that the risk of stroke in those with the highest serum levels of vitamin C was 29% lower than in those with the lowest serum levels of vitamin C .
A number of case-control studies have investigated the role of vitamin C in cancer prevention. Most have shown that higher intakes of vitamin C are associated with decreased incidence of cancers of the mouth, throat and vocal chords, esophagus, stomach, colon-rectum, and lung.
Decreased vitamin C levels in the lens of the eye have been associated with increased severity of cataracts in humans. Some, but not all, studies have observed increased dietary vitamin C intake and increased blood levels of vitamin C.
In a study of 747 older men, blood lead levels were significantly higher in those who reported total dietary vitamin C intakes averaging less than 109 mg/day compared to men who reported higher vitamin C intakes
Dr H's comment:
Most nutritional experts nowadays recommend us to take 1000-2000 mg vitamin C daily in order to prevent the current epidemic of chronic diseases.(regular multivitamin contains about 60 mg vitamin c, so you need to take it separately)
on Linus Pauling: