Sepsis and septicemiaPatient friendly summary

  • UVB light from the sun reduces the risk of sepsis by producing vitamin D.
  • Vitamin D reduces the risk of sepsis by producing cathelicidin. This protein fights bacterial infections.

Sepsis is a severe illness. It is caused by a bacterial infection that begins anywhere in the body and moves to the blood. The bloodstream is soon overwhelmed by bacteria.

Each year in the United States, more than one million people are diagnosed with sepsis. About 200,000 people die. Many deaths are noted in the Southeast United States. Nearly 60% of sepsis cases are associated with respiratory infections.

Risk factors

A number of risk factors are associated with sepsis:

  • Hospitalization and surgery: It is easy for bacterial infections to spread within a hospital. Surgery allows bacteria to have direct contact with the blood.
  • Respiratory infections and smoking: Both of these damage the lining of the lungs. Then bacteria can more easily make contact with the blood.

Poorer outcomes may occur in those who are:

  • Obese or smoke
  • Premature, low birth-weight infants (They have poorly developed immune systems.)

Sunlight exposure and risk

There is a lot of evidence that solar ultraviolet-B (UVB) light reduces the risk of sepsis:

  • Sepsis rates are highest in the winter/spring and lowest in the summer/fall.
  • African-Americans have higher hospitalization rates for sepsis than white Americans. Overall, African-Americans have lower vitamin D blood levels than white Americans (16 ng/mL [40 nmol/L] vs 26 ng/mL [65 nmol/L]).

People with cancer and other diseases associated with low vitamin D blood levels have higher rates of sepsis.

Vitamin D and sepsis

Vitamin D levels  

Vitamin D has been found to lower bacteria infection rates, as seen in two studies: 

  • At Emory University (Atlanta), patients with sepsis or in an intensive care unit (ICU) had lower vitamin D blood levels than healthy controls. Mean blood cathelicidin levels were significantly lower in critically subjects compared to healthy controls. Cathelicidin is a protein that fights infections.
  • In Tennessee, patients in an ICU had similar vitamin D levels as healthy controls. Those with lower vitamin D levels had poorer outcomes. 53% of those who died in the ICU or shortly thereafter had vitamin D levels below 20 ng/ml (50 nmol/l) compared to 28% of those who survived.

How vitamin D works

Vitamin D fights bacterial infections by producing proteins called cathelicidin and defensins. They can be considered antiseptic molecules.


There are no reported studies showing that higher vitamin D levels reduce the risk of sepsis. However, vitamin D reduces the risk of other diseases. Therefore, high vitamin D blood levels (40 ng/mL [100 nmol/L]) may reduce the risk of sepsis.

Those planning for a hospital stay should consider increasing their vitamin D blood levels to this amount. Take 10,000–50,000 international units (IU) (250-1250 mcg)/day of vitamin D for a few days to quickly bring the levels up. After that, reduce the intake to 1000–5000 IU (25-125 mcg)/day. It would be worthwhile to have vitamin D levels measured before going to the hospital.


There are no reported studies of using vitamin D to treat sepsis. However, it takes 1–2 days for the body to make cathelicidin after vitamin D from oral intake or UVB. Thus, vitamin D may a secondary way to treat sepsis in conjunction with antibiotics.

Find out more...

Do you want to find out more and see the research upon which this summary is based?  Read our detailed evidence summary on Sepsis and septicemia.

Page last edited: 06 May 2011