Guest guest Posted August 30, 2010 Report Share Posted August 30, 2010 Vitamin A Hikes HIV Loads in Breast Milk HIV-positive mothers may be more likely to infect infants via breast milk if they take vitamin A and beta-carotene supplements, researchers have found. In two analyses of a cohort of HIV-positive Tanzanian women, those who took the vitamins had significantly higher viral loads in their breast milk than those who didn't take them (P=0.02), according to Villamor, MD, PhD, of the University of Michigan, and colleagues. They also had a higher risk of subclinical mastitis, an inflammatory response that causes tight junctions in the mammary epithelium to open, allowing extracellular fluid to flow from plasma to milk. Villamor said this could be the mechanism explaining the association with viral load. "Daily supplementation with these nutrients at the doses tested in the trial should probably not be given to HIV-infected lactating women," Villamor told MedPage Today in an e-mail. The analyses were published in separate papers in the American Journal of Clinical Nutrition and the Journal of Nutrition, respectively. Both come from a randomized, controlled trial of 1,078 HIV-infected women in Dar es Salaam, Tanzania, who received one of four regimens: vitamin A and beta-carotene (5,000 IU and 30 mg, respectively); B-complex vitamins along with vitamins C and E; a multivitamin plus vitamin A and beta-carotene; or placebo. The American Journal of Clinical Nutrition study looked at 594 of these women who were infected with HIV and had breast milk samples taken. The researchers found that the proportion of breast milk samples with detectable viral load was significantly higher in women who received regimens with vitamin A and beta-carotene than in the other groups (51.3% versus 44.8%, P=0.02). The effect was apparent at least six months postpartum, they said, with a 34% increased risk of HIV shedding in milk at that time (relative risk 1.34, 95% CI 1.04 to 1.73). There were no significant differences between women who received multivitamins and those who took placebo, they added. They also found that breast milk concentrations of beta-carotene were related to increased detectable viral load in milk. One mechanism by which this occurs may be subclinical mastitis, assessed in the Journal of Nutrition study. A subset of 674 participants had subclinical mastitis assessed, measured by sodium-to-potassium ratio in breast milk. The researchers found that those on vitamin A and beta-carotene had a 45% increased risk of severe subclinical mastitis (P=0.03), with nonsignificant trends toward greater risk of moderate subclinical mastitis or any degree of the condition. Those taking multivitamins without vitamin A and beta-carotene had a 33% greater risk of subclinical mastitis (P=0.005) and a 75% greater risk of severe subclinical mastitis (P=0.0006) than women on placebo. The researchers called these findings "unexpected," attributing their effects to an increased inflammatory response. Women taking multivitamins plus vitamin A and beta-carotene had trends toward increased risks, but again they were not significant. The researchers also found that among women with CD4+ T-cell counts of 350 or greater, multivitamin intake resulted in a 49% increased risk of any subclinical mastitis (P=0.006). However, multivitamins had no effects among those with lower counts. The analyses were limited because they lacked details on clinical breast symptoms and on breast-feeding practices. Villamor told MedPage Today that the risk from vitamins other than vitamin A and beta-carotene is "outweighed by the benefits" -- which in previous studies have included better outcomes in terms of disease progression, child growth, diarrhea, and anemia. But vitamin A and beta-carotene do seem clearly problematic, he said. There are now "strong arguments to consider the implications of supplementation to pregnant or lactating women who are HIV-positive. It does not look like it's a safe intervention for them," Villamor said. Primary source: American Journal of Clinical NutritionSource reference:Villamor E, et al "Effect of vitamin supplements on HIV shedding in breast milk" Am J Clin Nutr 2010; DOI: 10.3945/ajcn.2010.29339. Additional source: Journal of NutritionSource reference:Arsenault JE, et al "Vitamin supplementation increases risk of subclinical mastitis in HIV-infected women" J Nutr 2010; DOI: 10.3945/jn.110.122713. http://www.medpagetoday.com/InfectiousDisease/HIVAIDS/21944 Quote Link to comment Share on other sites More sharing options...
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