Vitamin C intake and cancer mortality:
Carr and Frei recommended a higher vitamin C intake of 90-100 mg per day to avoid chronic diseases after reviewing cohort studies. They found that low intake of vitamin C was related to an increase in cancer mortality. They also had a different conclusion than Loria et al in that intake of vitamin C was inversely related to cancer mortality in elderly women but not mortality in men. (50)
An analysis, was conducted on 19,496 men and women, ages 45 to 79, in the U.K. The participants’ blood was tested for ascorbic acid (a form of vitamin C) and they were placed in five groups (quintiles) according to their serum ascorbic acid levels. Men and women were tracked separately. The researchers observed deaths from cancer and all causes in each of the blood ascorbic acid quintiles. In every case (except for women at risk of cancer), death rates were significantly lower among those with higher blood ascorbic acid levels. People with the highest ascorbic acid levels had half the risk of dying from all causes combined. Additionally, a 20 micromol/L increase in blood ascorbic acid concentration, the same as a 50 g per day increase in fruit and vegetable intake, was associated with about a 20% reduction in risk of all-cause mortality. (26)