Sex Differences in Selenium Metabolism

Sex differences in selenium metabolism played a considerable role in the heart health outcomes of the KiSel-10 study. In that randomized controlled trial, the researchers administered 200 mcg/day selenium and 200 mg/day Coenzyme Q10 or matching placebos to elderly Swedish study participants with low selenium status. The combined supplementation significantly improved heart function and reduced cardiovascular mortality [Alehagen 2013].

Prof Urban Alehagen selenium researcher
Pictured lecturing, Prof. Urban Alehagen is the chief researcher and the lead author on many of the KiSel-10 Study publications. His work has shown the heart health benefits of selenium supplementation in elderly individuals low in selenium.

Note that, on average,  the baseline selenium status in the KiSel-10 study participants was at a deficiency level, 67.1 mcg/L. The elderly citizens’ CoQ10 level was only borderline satisfactory, 0.82 mg/L at the study start. Prof. Urban Alehagen and the KiSel-10 research team knew that a low selenium intakes and an aging-related decline in CoQ10 bio-synthesis are associated with increased risk of cardiovascular disease [Alehagen 2013; Alehagen 2020]. read more

Selenium Status and Mortality Risk

All-cause mortality, cancer mortality, and cardiovascular disease mortality are all three significantly associated with selenium status in the blood. Higher selenium status correlates with lower mortality risk. In particular, the inverse relationship with all-cause mortality was strong among different study populations in different countries and in different study regions. The inverse relationship was strong with different selenium measurement methods, with different study recruitment years, and with different study sizes and study follow-up lengths [Cui 2025].

Grave of Edith Piaf in the Pere Lachaise cemetery
Nearly a billion people in the world live in selenium-poor regions. Low selenium status in humans is strongly associated with an increased mortality risk.

These are the conclusions from a systematic review and meta-analysis of 20 observational studies that enrolled 67,534 study participants. The studies included 17 studies of all-cause mortality, 7 studies of cancer mortality, and 9 studies of cardiovascular disease mortality. The review shows that a concentration increase of one standard deviation in serum or plasma selenium biomarkers was associated with 13% lower all-cause mortality, 15% lower cancer mortality, and 11% lower cardiovascular mortality [Cui 2025]. read more