FOR IMMEDIATE RELEASE                                                                                                                                                     Update 6 June, 2020

Contact:                                                                                                                                                                                      Mardi Crane-Godreau, PhD                                                                                                                                                   EMAIL:


 Innate immune protection against COVID-19 is compromised by vitamin D deficiency & air pollution.


Protection against COVID-19 requires both adequate vitamin D and clean air. 

Absence of LL37, a naturally occurring anti-viral secretion of the human respiratory tract, may explain serious vs. mild COVID-19 symptoms.  Production of LL37 is regulated by Vitamin D. Individuals with vitamin D deficiency may not produce adequate LL37 to protect against the COVID-19 or other viral infections.

LL37 destroys envelope viruses by damaging their envelope. This happens by virtue of its positive electrical charge.  When fine particles in air pollution come in contact with LL37, they neutralize the positive charge of LL37, leaving LL37 inert. This leaves viruses to reproduce and spread freely.  Consistent with observations of high death rates and high levels of pollution in COVID-19 hot spots, the neutralization of LL37 by nanoparticles may explain these phenomena.

Protection against COVID-19 requires both adequate vitamin D and clean air.  Interestingly, the absence of either or both, has adverse impact on the ability to fight any viral infection.  Since LL37 also modulates immune responses, its absence not only leaves those with viral infections vulnerable to direct viral damage but also to inflammatory responses by the immune system.

Crane-Godreau, Clem, Payne and Fiering, a team of Dartmouth scientists, published their insights in Frontiers in Public Health.

Dr. Crane-Godreau, explained, “Our innate immune system is the first line of defense against infection and the only line of defense when the body is challenged by a novel microbe. It takes days to weeks to develop antibodies, but in the mean time, you have to survive the infection.  LL37 plays a critical role in protecting against both viral and bacterial infections. The body requires adequate vitamin D to regulate its production.  This is consistent with reports by scientist and doctors, that vitamin D is playing a role in reducing the impact of the virus.”

Crane-Godreau commented, “Early in the pandemic, while we felt that LL37 was likely protecting populations with adequate vitamin D levels, we were perplexed by the high death rates in various high pollution hot spots.  Further investigation led to our understanding that LL37 can be neutralized by coming in contact with carbon nanoparticles. Those are the fine particles found in industrial and transportation associated air pollution. Risk exists from other sources of air pollution including wood burning stoves and primary and second-hand smoke. ”

Emergency medicine clinician and co-author, Dr. Kathleen Clem, pointed to the link between adequate vitamin D levels and better outcomes in patients who contract COVID-19. She added “Air quality is also a factor. While mask-wearing decreases spread of the virus, the correct types of masks can also protect against poor air quality. We see both clean air and adequate vitamin D levels as necessary to minimize illness and deaths from COVID-19.”

LL37 has demonstrated antiviral activity against several other envelope viruses including Respiratory Syncytial Virus, Influenza A, Hepatitis C, Dengue Virus, HIV-1 and Vaccinia Virus.  It does this by destroying the envelope with its positive charge.

The paper calls for development of relevant protocols for prevention and treatment of COVID-19.  The authors also call for mitigation of exposure to fine particles from industrial and transportation associated air pollution as well as from primary and second-hand tobacco smoke and other domestic sources.

COVID- figure -diagram w legend