People who boost their vitamin D levels with supplements reduce their risk of respiratory tract infections, such as the flu, by up to 12%, according to a new systematic review and meta-analysis study of 25 randomized controlled trial (RCT) studies published in The BMJ.
The study reported that this equates to one person being spared a respiratory tract infection (RTI) for every 33 taking vitamin D supplements. The benefit is greater in those receiving daily or weekly vitamin D versus bolus or monthly dosing, with the number needed to treat dropping to 20. The impact in Canada, based on a population of 35 million people, shows vitamin D could spare 1.75 million people having one RTI per year.
Vitamin D researchers have suspected for a long time that RCT studies, which used bolus or monthly dosing and reported minimal benefits, were diminishing the true positive effects of vitamin D, especially in systematic review and meta-analysis. This latest study, “Vitamin D supplementation to prevent acute respiratory tract infections: Systematic review and meta-analysis of individual participant data,” was able to prove that bolus or monthly dosing is ineffective. It found:
• 12% reduction of RTIs based on all studies and all dosing regimens.
• 19% reduction of RTIs for those receiving daily or weekly vitamin D doses.
• No statistically significant effect on risk of RTIs for those receiving bolus or monthly dosing.
• 70% reduction in RTIs for those with low vitamin D blood levels below 25 nmol/L and receiving weekly or daily dosing of vitamin D.
Above is the information needed to cite this article in your paper or presentation. The International Committee
of Medical Journal Editors (ICMJE) recommends the following citation style, which is the now nearly universally
accepted citation style for scientific papers:
Halpern SD, Ubel PA, Caplan AL, Marion DW, Palmer AM, Schiding JK, et al. Solid-organ transplantation in HIV-infected patients. N Engl J Med. 2002;347:284-7.
About the ICMJE and citation styles
The ICMJE is small group of editors of general medical journals who first met informally in Vancouver, British Columbia, in 1978 to establish guidelines for the format of manuscripts submitted to their journals. The group became known as the Vancouver Group. Its requirements for manuscripts, including formats for bibliographic references developed by the U.S. National Library of Medicine (NLM), were first published in 1979. The Vancouver Group expanded and evolved into the International Committee of Medical Journal Editors (ICMJE), which meets annually. The ICMJE created the Recommendations for the Conduct, Reporting, Editing, and Publication of Scholarly Work in Medical Journals to help authors and editors create and distribute accurate, clear, easily accessible reports of biomedical studies.
An alternate version of ICMJE style is to additionally list the month an issue number, but since most journals use continuous pagination, the shorter form provides sufficient information to locate the reference. The NLM now lists all authors.
BCMJ standard citation style is a slight modification of the ICMJE/NLM style, as follows:
- Only the first three authors are listed, followed by "et al."
- There is no period after the journal name.
- Page numbers are not abbreviated.
For more information on the ICMJE Recommendations for the Conduct, Reporting, Editing, and Publication of Scholarly Work in Medical Journals, visit www.icmje.org