Selenium and cardiometabolic health: inconclusive yet intriguing evidence.

Selenium is incorporated as the unique amino acid selenocysteine into selenoproteins, which regulate important biologic processes such as redox balance. The results of epidemiologic and clinical investigations are inconclusive regarding the relation of the plasma selenium level to cardiometabolic parameters and does not support the routine use of selenium supplements to prevent cancer or cardiovascular disease. Variability in the selenium status of the populations studied and lack of standardization of measures of selenium status may account for part of the confusion regarding selenium and cardiometabolic health. Another possibility is that differences in the effects of selenoproteins, as opposed to those of low-molecular-weight selenium compounds derived from in vivo metabolism of selenium, may explain the unusual phenomenon of a similar phenotype induced by both selenium deficiency and excess in experimental models and offer a plausible explanation for the lack of consistency in clinical studies. The epidemiologic, clinical, and experimental evidence, although inconclusive in terms of the precise relation of selenium to cardiometabolic health, is however very intriguing in terms of the urgent need for further mechanistic research to enable the clinical use of this potent micronutrient.