Zinc and respiratory health
Zinc supplementation was associated with a 41% decrease in pneumonia and a 25% decrease in diarrhea in children under the age of 5 years, in developing countries. The authors of this study noted that for reducing diarrhea, zinc supplementation is comparable with such other interventions as clean water, sanitation, and breastfeeding. Moreover, they said zinc supplementation has shown a greater preventive effect for pneumonia than other interventions currently in use. Randomized controlled trials included in the pooled analysis provided oral supplements containing at least half of the US recommended daily allowance (RDA) of zinc (15 mg) to children under the age of 5 years.
J Pediatr 1999 Dec;135(6):689-97
Selenium and HCC
Both experimental and epidemiological studies have linked a low dietary intake of selenium with an increased risk of cancer. In a long term study, researchers examined the association between plasma selenium levels and risk of hepatocellular carcinoma (HCC) among chronic carriers of hepatitis B and/or C virus in a cohort of 7,342 men in Taiwan. Patients suffering from HCC had reduced plasma selenium levels. This association was more pronounced among cigarette smokers and among subjects with low plasma levels of retinol or various carotenoids.
Am J Epidemiol, 150(4):367-74 1999 Aug 15