Vitamin C megadosage the airways as a result of vigorous exercise. EIB seems to be caused by the loss of water caused by increased ventilation, which may lead to the release of mediators such as histamine, prostaglandins and leukotrienes, all of which cause bronchoconstriction. Vitamin C participates in the metabolism of these mediators and might thereby influence EIB. A meta-analysis showed that 0.5 to 2 g/day of vitamin C before exercise decreased EIB by half. A meta-analysis showed a significant positive effect of vitamin C on endothelial function. Benefit was found of vitamin C in doses in the range from 0.5 to 4
Scurvy caused by ptomaine, a waste product of bacteria, particularly in tainted tinned meat. Infantile scurvy emerged in the late 19th century because children were being fed pasteurized cow's milk, particularly in the urban upper class. While pasteurization killed bacteria, it also destroyed vitamin C. This was eventually resolved by supplementing with onion juice or cooked potatoes. By the early 20th century, when Robert Falcon Scott made his first expedition to the Antarctic (1901–1904), the prevailing theory was that scurvy was caused by "ptomaine poisoning", particularly in tinned meat. However, Scott discovered that a diet of fresh meat from Antarctic seals