WHO Vitamin C Guidelines from World War II Study Challenged

Source: Diana Polekhina on Unsplash

Researchers have re-analysed a landmark study on Vitamin C conducted during World War II, which informed the WHO’s recommended daily amount, finding the amount to be half that actually required.

When food was scarce during World War II, gruelling experiments were conducted in Britain to determine the bare minimums of food and water that were required for health and survival, and how to prioritise the allocation of food.

One of the more robust experiments run on human subjects during this time in Britain, which has had long-lasting public health consequences, was a vitamin C depletion study started in 1944. This medical experiment involved 20 subjects, most of whom were conscientious objectors living in a building in Sorby where many similar experiments were conducted. They were overseen by a future Nobel Prize winner, and detailed data was kept on each participant in the study.

“The vitamin C experiment is a shocking study,” said Philippe Hujoel, lead author of a new analysis of the Sorby vitamin C experiment, a practicing dentist and professor of oral health sciences in the UW School of Dentistry. “They depleted people’s vitamin C levels long-term and created life-threatening emergencies. It would never fly now.”

Despite two participants developing life-threatening heart problems from the vitamin C depletion, Hujoel added, none of the subjects were permanently harmed, and later many indicated they would participate again.

Due to vitamin C shortages, they wanted to be conservative with the supplies, explained Hujoel, who is also an adjunct professor of epidemiology. The goal of the Sorby investigators was not to determine the required vitamin C intake for optimal health; it was to find out the minimum vitamin C requirements for preventing scurvy.

Vitamin C is important for wound healing because scar tissue formation depends on collagen, which needs vitamin C. In addition to knitting skin back together, collagen also maintains the integrity of blood vessel walls, thus protecting against stroke and heart disease.

In the Sorby trial, researchers assigned participants to zero, 10 or 70 milligrams a day for an average of nine months. The depleted subjects were then repleted and saturated with vitamin C. Experimental wounds were made during this depletion and repletion. The scar strength of these experimental wounds was a measure of adequate vitamin C levels since poor wound healing, in addition to such conditions as bleeding gums, is indicative of scurvy.

The Sorby researchers concluded that 10 milligrams a day was enough to ward off signs of scurvy. Partly based on this, the WHO recommends 45 milligrams a day. Hujoel said that the re-analyses of the Sorby data suggest that the WHOrecommendation is too low to prevent weak scar strength.

In a bit of scientific detective work, Hujoel said he tracked down and reviewed the study’s data, and with the aid of Margaux Hujoel, a scientist with Brigham and Women’s Hospital/Harvard Medical School, put the data through modern statistical techniques designed to handle small sample sizes, techniques not available to the original scientists. They published their findings in the American Journal of Clinical Nutrition.

The Hujoels found that the data from this unique study, which formed a cornerstone for dietary recommendations worldwide, needed more than just being assessed with the ‘eyeball method’.

“It is concluded that the failure to reevaluate the data of a landmark trial with novel statistical methods as they became available may have led to a misleading narrative on the vitamin C needs for the prevention and treatment of collagen-related pathologies,” the researchers wrote.

“Robust parametric analyses of the (Sorby) trial data reveal that an average daily vitamin C intake of 95 mg is required to prevent weak scar strength for 97.5% of the population. Such a vitamin C intake is more than double the daily 45 mg vitamin C intake recommended by the WHO but is consistent with the writing panels for the National Academy of Medicine and (other) countries,” they added.

The Hujoels’ study also found that recovery from a vitamin C deficiency is lengthy, requiring higher levels of vitamin C. Even an average daily dose of 90 milligrams a day of vitamin C for six months failed to restore normal scar strength for the depleted study participants.

Source: University of Washington

Leave a Reply