In 1970, two time Nobel prize winner Linus Pauling published a book called “Vitamin C and the common cold”. In it he argued that large supplemental doses of vitamin C could be used to decrease the length and severity of colds. This was the beginning of decades of controversy surrounding vitamin C (a.k.a. ascorbic acid) and its role in preventing respiratory infections, and resulted in Linus Pauling spending the last few decades of his life being derided as a quack by the medical establishment. But was he wrong?
A new article has just been published in the Journal of Steroid Biochemistry and Molecular Biology looking to see if an oral vitamin D supplement can be used to cure covid-19. Considering that vitamin D is cheap, widely available, and safe, it would be pretty miraculous if that turned out to be the case.
A new study has just been published in JAMA (the Journal of the American Medical Association) that seeks to answer this question definitively. This subject has been somewhat controversial, because observational studies have tended to show a positive effect, while randomised clinical trials have failed to show any effect. Usually you would trust the trial data more than the observational data, but these trials were all relatively short (generally a year or less), had relatively small study groups, and often used quite low doses of vitamin D.
This question has actually been pretty thoroughly researched, so it should be possible to come up with a conclusive answer. A systematic review and meta-analysis of the collected data was published in the British Journal of Medicine in 2017. The review was funded by the National Institutes of Health (NIH). No companies standing to benefit from the sale of vitamin D supplements were involved in funding the study and none of the authors had financial ties to any such companies. That makes me quite prone to trust the data.