By David Liu, PHD

Tuesday July 24,  2012 (foodconsumer.org) -- If you carry HIV virus, you would be better off taking vitamin D supplements or sunbathing every day for at least half a hour per day at the hottest hours of the day.  According to a new study published recently in PLoS Pathog., low vitamin D levels or vitamin D insufficiency in persons infected with human immunodeficiency virus type-1 (HIV) were associated with more rapid disease progression and increased risk for Mycobacterium tuberculosis infection.

G.R. Campbell and S.A. Spector, authors of the study report, said they have previously demonstrated that 1α,25-dihydroxycholecalciferol (1,25D3), the active form of vitamin D, inhibits HIV replication in human macrophages through the induction of autophagy. 

The current study resulted in more details about the anti-HIV effect.  The researchers found "physiological concentrations of 1,25D3 can induce the production of the human cathelicidin microbial peptide and autophagic flux in HIV and M. tuberculosis co-infected human macrophages which inhibits mycobacterial growth and the replication of HIV."

They also found "the 1,25D3-mediated inhibition of HIV replication and mycobacterial growth during single infection or dual infection is dependent not only upon the induction of autophagy, but also through phagosomal maturation." 

Moreover, the human cathelicidin microbial peptide was found essential for the vitamin d induced autophagic flux and inhibition of HIV replication and mycobacterial growth. 

The findings suggest that vitamin D sufficiency provides important benefits to HIV and M. tuberculosis-infected persons, and this vitamin may play a role in preventing and treating HIV infection and related opportunistic infections.