An interesting study performed on Korean office workers who experienced high levels of fatigue found that giving them a large dose of 10 grams of vitamin C significantly reduced feelings of exhaustion.
Vitamin C is so effective at treating tiredness because it decreases oxidative stress, which is thought to underlie fatigue. People with higher levels of oxidative stress in the form of reactive oxygen species and cytokines report being chronically tired at a much higher rate than people with low levels of oxidative stress.
It makes sense because oxidative stress causes cellular aging and death that damages DNA. The immune system gets blunted and you feel tired. Over time, fatigue sets in, and research suggests that oxidative stress will also lead to poor sleep and insomnia—it becomes a vicious cycle.
Vitamin C prevents this by eliminating oxidative stress markers so that you don’t feel as tired. Another possible benefit is that vitamin C has been found to lower cortisol in stressful situations, such as after exercise.
The Korean study used a large dose of 10 grams of vitamin C administered intravenously—a method that is particularly effective for elevating blood plasma levels for a therapeutic effect. Conventional vitamin C taken in capsule form by the mouth delivers all of the vitamin C at once, which can lead to diarrhea or low rates of absorption. Only about 100 mg of vitamin C is absorbable at a time in the GI tract, with the rest being eliminated in the urine.
You probably aren’t going to go to the hassle of getting intravenous vitamin C treatments for fatigue (they are available, particularly at cancer treatment clinics), but you may benefit from taking a large dose in a buffered form, which allows it to be absorbed over time in the gut. Our Uber C-TR (Time Release) product releases vitamin C over 12 hours to mimic the digestion of food and ensure the vitamin C is able to raise blood levels where it can have a positive effect on easing stress and fatigue.