Mega Doses of Vitamins No Help in HIV

A big boost of vitamins won't help outcomes in HIV for individuals starting treatment, a trial showed.

High-dose daily multivitamins started at the initiation of highly-active antiretroviral treatment (HAART) had no impact on AIDS-related mortality (4% versus 4%, RR 1.14, 95% CI 0.82 to 1.58) or on disease progression compared with a standard multivitamin providing only the daily recommended amounts, Sheila Isanaka, ScD, of Harvard School of Public Health, and colleagues found.

Other markers like CD4 count and plasma viral load also showed no advantage for the higher vitamin dose, while there was a signal for concern with elevated liver enzymes, they reported in the Oct. 17 issue of the Journal of the American Medical Association.

Multivitamins do play a crucial role in supporting the immune system, but more may not be better, the researchers concluded.

"In the absence of clear evidence of the benefit of high-dose micronutrient supplementation on morbidity and mortality in adults receiving HAART, it is prudent to follow current recommendations to promote and support adequate dietary intake of micronutrients at recommended daily allowance levels," they wrote.

Prior trials had shown high-dose supplements to improve outcomes among infected individuals not yet on HAART, but results have been mixed in the small randomized studies that had been done in the context of HAART.

For an adequately powered look at safety and efficacy, Isanaka's group randomized 3,418 patients to double-blind multivitamin supplementation starting at the time of HAART initiation at one of seven clinics in Dar es Salaam, Tanzania.

Based on some observational evidence that HIV patients needed higher intakes to achieve normal serum concentrations, the high-dose multivitamin contained two to 21 times the recommended daily allowance (RDA) for the B vitamins, double the daily recommended level of vitamin E, and 6 times the daily requirement of vitamin C.

The control group got a daily supplement containing just the recommended daily allowance of these vitamins "rather than placebo, to increase the generalizability of our findings to patients in developed and developing countries where a standard RDA multivitamin supplement may be consumed."

The study had to be stopped early after 15 months due to elevated alanine transaminase levels in the high-dose group. Overall, 38% of the patients had levels above normal, which was 44% more likely with the high-dose multivitamin (P=0.006).

The researchers called this a concern but noted that there's no plausible mechanism, since prior studies have not shown such an effect in any setting with high-dose multivitamins.

The only other difference in adverse events between the groups was neuropathy, which was actually less common in the high-dose supplement group (incidence rate ratio 0.81, P=0.004), possibly because vitamin E deficiency has been linked to peripheral neuropathy.