By Hara Estroff Marano, published on October 1, 2002 - last reviewed on April 25, 2005
It's already everybody's favorite nutritional supplement, linked,
however controversially, to preventing the common cold and fighting
cancer. But vitamin C recently added a new notch on its belt. The vitamin
helps reduce both the physical and psychological effects of stress on
People who have high levels of vitamin C do not show the expected
mental and physical signs of stress when subjected to acute psychological
challenges. What's more, they bounce back from stressful situations
faster than people with low levels of vitamin C in their blood.
In one study German researchers subjected 120 people to a sure-fire
stressor -- a public speaking task combined with mental math problems. Half
of those studied were given 1,000 mg of vitamin C.
Such signs of stress as elevated levels of the stress hormone
cortisol and high blood pressure were significantly greater in those who
did not get the vitamin supplement. Those who got vitamin C reported that
they felt less stressed when they got the vitamin.
The researchers believe that vitamin C should be considered an
essential part of stress management.
Earlier studies showed that vitamin C abolished secretion of
cortisol in animals that had been subjected to repeated stress. Cortisol
is a hormone released by the adrenal glands in response to stress. Once
it gets into the bloodstream, it is responsible for relaying the news of
stress to all parts of the body and mind.
Cortisol is the hormone, for example, that triggers the fight or
flight response to stress that allows us to spring into action when we
sense danger. But like many emergency-alert systems, the stress response
comes at a considerable cost.
In the animal studies, vitamin C fed to rats undergoing stress
prevented the expected increase in cortisol levels. In addition, it
prevented the animals from exhibiting the known signs of physical and
emotional stress, including loss of body weight.
Among animals that did not receive vitamin C, the level of stress
hormones in the blood was three times greater.
The present recommended daily allowannce (RDA) for vitamin C for
adults is 60 milligrams -- a far cry from the 1,000 mg found helpful in the
stress study. But there's a growing belief that the RDA for vitamin C is
The current RDA for vitamin C was set decades ago. It is based on
the amount of the vitamin needed to ward off scurvy.
Current thinking looks at vitamin C from the opposite direction:
The amount needed to promote health under varying environmental
conditions. That appears to be a lot greater than the amount needed to
There's also evidence suggesting that prehistoric humans consumed
large amounts of vitamin C in a tropical diet rich in fresh fruits. If
so, the physiological constitution we have inherited may require far
larger daily doses of vitamin C than the current RDA, perhaps as high as
Vitamin C is abundant in fresh, uncooked fruits and vegetables,
most notably in citrus fruits and both red and green peppers. One
eight-ounce glass of fresh orange juice provides 97 mg of the
It's also found in papayas, cantaloupes, strawberries, broccoli,
Brussels sprouts, tomatoes, asparagus and parsley. You will not find
vitamin C in animal food, and only a small amount in raw fish.
An unstable substance, vitamin C is destroyed by cooking and
exposure of food to light.
As the most commonly consumed nutrient supplement, vitamin C comes
in many formulations. But the best may be a time-released preparation
that works over the course of a day, as the vitamin works rapidly and is
short-acting. Alternatively, smaller-dose vitamin C supplements can be
taken at intervals throughout the day.