Vitamin D may boost immunity against HIV

Deficiency of vitamin D - the sunshine vitamin - can help individuals to fight against the infections caused by human immunodeficiency virus (HIV), a research has found.

High-dose vitamin D supplementation can reverse the deficiency and also improve immune response, the results showed.

"Vitamin D may be a simple, cost-effective intervention, particularly in resource-poor settings, to reduce HIV-1 risk and disease progression," the researchers reported in the online issue of Proceedings of the National Academy of Sciences.

The researchers examined two ethnic groups of South Africa's Cape Town to see whether high-dose vitamin D supplementation improved deficiencies and the cell's ability to repel HIV-1.

"Cape Town has a seasonal ultraviolet B regime and one of the world's highest rates of HIV-1 infection, peaking in young adults, making it an appropriate location for a longitudinal study like this one," said lead researcher Nina Jablonski, professor at Pennsylvania State University in the US.

The researchers found that both groups exhibited vitamin D deficiency during the winter, with women in both groups being more deficient, on average, than the men.

Because of vitamin D's impact on the immune system, the researchers provided six weeks of supplemental vitamin D3 to 30 of the Xhosa participants, which brought 77 percent of the participants to optimal vitamin D status.

Jablonski and her team determined that diet, genetics and other variables played very small roles in vitamin D status, although some genetic variations did influence the success of supplementation.

To test how vitamin D status affected the immune system and HIV-1 in particular, the researchers exposed the blood samples taken during the summer and winter when the participants were vitamin D sufficient or deficient.

They found that after nine days, the winter blood samples had greater infection than those taken in summer.

After six weeks of vitamin D supplementation, the blood sample levels of HIV-1 infection were same as those during the summer.

"High-dosage oral vitamin D3 supplementation attenuated HIV-1 replication, increased circulating white blood cells and reversed winter-associated anemia."