Selenium content of rice, mixed plant foods and fish from Bangladesh

Selenium (Se), an essential trace mineral, is obtained by individuals from foods ingested and is necessary for 25 human proteins including the antioxidant family of glutathione peroxidases. Since plants are not known to require Se for growth, the quantity of this mineral in plant foods depends on the soluble Se in soils that is passively accumulated by plants. As all animals require Se, it is usually stored more uniformly and to a greater degree in animal than plant protein foods. Owing to the alluvial origin, high rainfall and flooding upon the soils of Bangladesh these soils appear to be low in measured soluble Se. These low levels of soluble Se in Bangladeshi soils reflect the low levels of Se in plant foods, rice and vegetables, staples of the rural and poor Bangladeshi's diet. This study reports on the dry-weight content of Se found in samples of rice, other plant foods and fish from Bangladesh. Rice grain averaged 0.105 μg Se g-1 from Jessore and 0.212 μg Se g-1 from 5 other districts of Bangladesh. Gourds and potatoes from Jessore averaged 0.471 and 0.181 μg Se g-1 respectively. All other district plant foods averaged 0.26 μg Se g-1. All 7 different but unidentified species of fish sampled in Jessore and quantitated fluorimetrically averaged 1.318 μg Se g-1. Fish was the single highest food source of dietary Se per unit dry weight. Fish in particular, but also other animal foods, are likely to serve as better dietary sources of Se for the people of Bangladesh.