HIV and Vitamin D

HIV treatment guidelines around the world recommend tenofovir (Viread, also in the combination pills Truvada, Eviplera and Atripla) in first-line HIV treatment. The drug is effective, easy to take and generally has few side-effects.

However, treatment with tenofovir has been linked to both kidney and bone problems, including the loss of bone density. Tenofovir may affect bone health because it alters levels of parathyroid hormone, a substance that controls the amount of calcium in the blood and bones.

Many people living with HIV do not have enough vitamin D, a nutrient that also helps control the level of calcium in the body. Low vitamin D levels have been linked with poorer kidney function and higher levels of parathyroid hormone in people who are HIV negative. Vitamin D supplements have been shown to help with both these health problems. However, the benefit of vitamin D supplements for people with HIV has been less clear.

A US study looked at the effect of vitamin D supplements on vitamin D levels, parathyroid hormone levels, and other markers of bone health in HIV positive young adults. They compared the outcomes for participants who were taking HIV treatment that included tenofovir to those who were on different drug combinations.

Levels of vitamin D were similar in participants in both arms of the study. People with low levels of vitamin D had higher levels of parathyroid hormone; people on tenofovir-based treatment were particularly likely to have higher levels of parathyroid hormone.

The supplements were effective in increasing people’s levels of vitamin D. Taking them was linked to reduced levels of both parathyroid hormone and harmful bone changes in people on tenofovir. However, taking vitamin D supplements did not have a significant impact on parathyroid hormone levels in people who were not taking tenofovir, even if they had low vitamin D levels to start with.

The study only lasted 12 weeks, so the researchers couldn’t show if their findings had any longer-term impact on bone health. However, the study results suggest that supplements could be helpful for young people on tenofovir, and that further research into this area would be useful.