There is a direct, inverse correlation between vitamin D concentration and hepatitis B viral load, MedPage Today reports. German researchers examined samples taken from 203 treatment-naive study participants with hep B between 2009 and 2012 and presented their findings in the journal Hepatology.

“Vitamin D helps maintain a healthy immune system, and there is evidence of its role in inflammatory and metabolic liver disease, including infection with hepatitis C virus (HCV),” lead investigator Christian Lange, MD, from Johann Wolfgang Goethe University Hospital in Frankfurt, said in a release.

Thirty-four percent of the group had severe vitamin D deficiency (less than 10 nanograms of hydroxyvitamin-D per milliliter of blood); 47 percent were insufficient in their vitamin levels (less than 20 nanograms); and 19 percent had sufficient levels (more than 20 nanograms). The average overall concentration of 25-hydroxyvitamin D was 14.4 nanograms per milliliter of blood.

Those with hep B viral loads of less than 2,000 international units (IU) per milliliter averaged a vitamin D level of 17 nanograms per milliliter. Participants with viral loads above that set point had an average of 11 nanograms of vitamin D per milliliter.

The researchers also discovered that hep B viral load was lower during spring and summer months when compared with fall and winter. Exposure to sunlight increases vitamin D levels.

However, the researchers stressed that this study only proves a correlation between vitamin D and hepatitis B levels, and not a causational effect. Furthermore, because the study only focused on those who had not received treatment for the virus, its findings cannot be widely generalized.

To read the MedPage Today report, click here.

To read a release on the study, click here.