In one of the studies, 1,078 HIV-infected women were divided into four groups. The test groups received either 5,000 IU of vitamin A and 30 mg of beta-carotene everyday during gestation and the lactation period, or a control regimen. The dose for beta-carotene was higher than the amount usually provided by the diet, according to Villamor. Smaller doses might not have the same effect.

Villamor said tests trying to separate the effects of each nutrient showed that beta-carotene seemed to increase the amount of HIV in breast milk independent of vitamin A, but an effect of vitamin A alone cannot be ruled out. The findings are potentially controversial because vitamin A is an important supplement for postpartum women in countries where HIV infection is highly prevalent, but supplementation programs may not take into account a woman's HIV status.

"The takeaway is that daily supplementation of HIV-infected pregnant or lactating women with vitamin A and beta-carotene at the doses tested is probably not safe and efforts need to be strengthened on preventing mother-to-child transmission through other interventions such as anti-retroviral regimens," Villamor said.

Source: University of Michigan