New analysis of historic study indicates that we need more vitamin C
During World War II, food supplies were scarce. At one point, English researchers wanted to find out how little vitamin C it would take to prevent the potentially lethal disease, scurvy. In order to do that, they carried out a drastic experiment that later served as basis for our current vitamin C recommendations. However, a recent analysis of this old study has revealed that the actual need for vitamin C is a lot greater than previously thought, suggesting that WHO raise the recommended daily intake level. The question is how much vitamin C do we really need and what good does the vitamin do?
Vitamin C is an important constituent of collagen, a protein with structural importance for our blood vessels, gums, bones, and skin. Vitamin C is also important for the immune defense and for wound healing. Moreover, vitamin C serves as an important antioxidant that protects cells and tissues against free radicals. Most animals are able to synthesize enough vitamin C to meet their own needs. Humans, on the other hand, have lost this ability to evolution. We depend on vitamin C from our diets, mainly from sources like fruit and vegetables. The most serious consequence of a vitamin C deficiency is scurvy, a condition that typically includes symptoms such as fatigue, bleeding gums, bruising and impaired immunity.
World War II had far-reaching consequences for vitamin C recommendations
During World War II, the most basic foods were scarce. For that reason, British scientists wanted to find out if the limited food rations in the navy’s lifeboats were sufficient for people to survive. Also, they wanted to know how much vitamin C the general population needed in order to avoid scurvy, which is the classic vitamin C deficiency disease.
In one of the experiments that took place at Sorby Research Institute in Sheffield, a team of volunteers were fed only what the navy had in its lifeboats. This grueling experiment resulted in more water and less food being carried in lifeboats.
Another extreme experiment that took place at Sorby Research Institute was carried out as a vitamin C depletion study. The experiment was initiated in 1944 and had far-reaching consequences for future vitamin C recommendations. The study included 20 people who were already living in the building where the studies took place. They were fed a diet with either 0, 10, or 70 mg of vitamin D daily for a period of nine months on average. Afterwards, their vitamin C stores were repleted.
Because of the scarcity of foods with high vitamin C during the war period, the purpose of this experiment was not as much to find out how much vitamin C is needed for optimal health as to establish how little it would take to avoid scurvy.
During the course of the study, the scientists inflicted experimental wounds upon the participants. Afterwards, they studied the strength of the scar tissue to assess vitamin C levels, as it is known that being vitamin C-deficient impairs wound healing and scar tissue formation. It was also known that prolonged problems with bleeding gums may be a sign of scurvy.
The researchers ended up concluding that 10 mg of vitamin C daily was a sufficient intake to ward off any signs of scurvy. Later on, their experiment served as basis for WHO’s recommendations that called for 45 mg of vitamin C per day.
A shocking study with life-threatening consequences
Philippe Hujoel, who is a practicing dentist and professor at the UW School of Dentistry in Washington, USA, calls the old vitamin C experiment shocking. In fact, Hujoel is behind a new analysis that has revealed that the provoked vitamin C deficiency ended up causing life-threatening conditions in some of the participants. Today, an experiment like that would never be allowed.
In collaboration with a researcher from Brigham and Women’s Hospital/Harward Medical School, Hujoel has conducted what can best be described as scientific detective work by exposing the old data to modern techniques and analyses that were unavailable to scientists in old days. The result of this work has just been published in The American Journal of Clinical Nutrition.
We need more vitamin C
Philippe Hujoel found that the old data from the historic vitamin C study, the one that served as basis for WHO’s recommendations, needs to be reevaluated. He suggests 90 milligrams of vitamin C daily (twice as much as WHO recommends) as an appropriate average intake for preventing poor wound healing and weak scar tissue formation.
Hujoel’s study also showed that it takes a long time to recover from severe vitamin C depletion and that it requires an even higher intake than the recommended one. Even daily ingestion of 90 milligrams of vitamin C was not enough to restore normal scar tissue strength in those participants that were exposed to massive vitamin C depletion.
How do we get enough vitamin C – and what causes deficiency?
In Denmark, the daily reference intake (RI) level for vitamin C for adults and children older than 11 years is 80 mg per day. According to the new study, that level needs to be increased. It should also be added that factors such as smoking, suffering from chronic disease, stress, ageing processes, poisoning, lesions, and an overconsumption of stimulants can increase the need for the nutrient. The same is the case with a large sugar intake. Vitamin C and sugar compete for the same channels that lead into the cells. The more sugar one eats, the more this can reduce the effect of vitamin C.
The best way to ensure an adequate intake of vitamin C is by eating a balanced diet with plenty of fruit and vegetables. Vitamin C supplements typically contain 500-1,000 mg of vitamin C, and it is a good idea to choose non-acidic forms of vitamin C such as calcium ascorbate that are gentle on the stomach.
A small calculation
In order to get the same amount of vitamin C as one tablet with 750 mg of the nutrient, you would have to eat around 12 oranges or 53 apples.
Philippe P Hujoel, et al. Vitamin C and scar strength: analysis of a historical trial and implications for collagen-related pathologies. The American Journal of Clinical Nutrition. 2021
University of Washington. New analysis of landmark scurvy study leads to update on vitamin C needs. ScienceDaily August 16, 2021
Frida - Fødevare ID: 2 (fooddata.dk)
Search for more information...