Most controlled trials made on vitamin C and cold duration used a modest dosage of only one gram a day of vitamin C. Pooled data from these previous studies show a genuine effect between vitamin C intake and symptom improvement of the cold. Nevertheless, a definitive conclusion regarding dose-response has never been reached, particularly in terms of higher intake of vitamin C.
For the purpose of this study, Dr. Hemilä analyzed the findings of two randomized trials. In the first trial, two study groups were given three grams of vitamin C a day, another group six grams of vitamin C a day, and the last group a placebo. The group that took six grams of vitamin C a day experienced a 17 percent reduction in cold duration compared to the placebo group. This was twice as much as the three grams a day group. The second trial increased the dosages. In this trial, groups were given four grams of vitamin C a day, eight grams of vitamin C a day, or a placebo. As with the first trial, participants who took the higher amount showed a shorter cold duration. Both of these studies showed that there is indeed a direct relationship between vitamin C intake and cold duration. The dose-response link was linear up to amounts of six to eight grams a day. Nevertheless, Dr. Hemilä suggested that it is quite possible that even higher doses of vitamin C can result to even greater reductions in the duration of the common cold. She proposed an intake of upwards of 15 grams a day of vitamin C for the best treatment of cold. (Related: Can Vitamin C Really Cure Your Cold?)
“Given the consistent effect of vitamin C on the duration of colds, and its safety and low cost, it would be worthwhile for individual common cold patients to test whether therapeutic eight grams a day [of] vitamin C is beneficial to them,” she wrote in an article on Science Daily. “Self-dosing of vitamin C must be started as soon as possible after the onset of common cold symptoms to be most effective.”
Dr. Hemilä further added that more clinical trials should be conducted to fully investigate the dose-response relationship in vitamin C amounts over eight grams a day.
This is excellent news for the millions of people who get sick from the cold each year. Not only is the condition annoying, it also accounts for billions of dollars lost due to absenteeism. A 2002 study in J Occup Environ Med concluded that the economic loss of productivity due to the common cold is around $25 billion. This was further broken down to $16.6 billion from on-the-job productivity loss, $8 billion from absenteeism, and $230 million from caregiver absenteeism. In addition, each cold experienced by an adult caused an average of 8.7 lost work hours.
Read more articles on the healing benefits of vitamin C at Healing.news.
Sources include: