Having low vitamin D may compromise immune recovery among people with HIV after they start antiretroviral (ARV) treatment. To reach this conclusion, researchers studied 398 HIV-positive people who were starting treatment for the virus or who had done so within six months.

The participants with low vitamin D experienced smaller gains in their CD4 cell levels over an 18-month period than those with sufficient vitamin D levels.

“Our study suggests that HIV-infected persons should discuss with their physician the possible need for vitamin D supplementation, particularly if they are deficient” in the vitamin, says the study’s lead author, Amara E. Ezeamama, PhD, an assistant professor in epidemiology and biostatistics at the University of Georgia.

However, she adds that scientists do not know the exact dose of vitamin D to recommend to HIV-positive individuals. Additionally, research into the benefit of vitamin D supplementation among this population has been inconclusive. Further research is needed.