Selenium from pinto beans is bioavailable to support bone structure in mice

Abstract

Deficiency of selenium (Se), an essential trace mineral for animals and humans, has been shown to induce growth retardation and to impair bone metabolism. The objective of the study was to determine whether Se from pinto beans (SeBean) is as bioavailable as Se from selenomethionine (SeMet) to support bone health in mice. Male C57BL/6J mice at 18‐wk‐old were assigned randomly to three groups and fed purified Se‐deficient diet containing ~0.005 ppm Se (SeDef, n = 12), or diets containing ~0.1 ppm Se in the form of SeMet (n = 10) or SeBean (n = 11) for three months. Mice fed either SeMet or SeBean diet had significantly higher selenoprotein glutathione peroxidase activity in RBC and Se concentration in liver than those on SeDef diet (P < 0.01). Micro‐computed tomography was used to evaluate trabecular and cortical bone structure of distal and mid‐shaft femur. Both SeMet and SeBean diets significantly increased trabecular bone volume/total volume and trabecular number and decreased trabecular separation, as compared to SeDef diet. No differences were detected in any bone structural parameters between SeMet and SeBean groups (P > 0.05). This study shows that Se deficiency impairs bone metabolism and Se from pinto beans is bioavailable to support bone micro‐structure in mice. Supported by Northarvest Bean Growers Association.