Trends in selenium status of South Australians.

OBJECTIVE To assess trends in selenium status in South Australians from 1977 to 2002. DESIGN Six cross-sectional surveys. PARTICIPANTS 117 participants in 1977, 30 in 1979, 96 and 103 (separate surveys) in 1987, 200 in 1988, and 288 volunteer blood donors in 2002. A total of 834 healthy Australian adults (mean age, 42 years [range, 17-71 years]; 445 were male). MAIN OUTCOME MEASURES Plasma and whole blood selenium concentrations. RESULTS The 2002 survey yielded a mean plasma selenium concentration of 103 micro g/L (SE, 0.65), which reached the estimated nutritional adequacy level of 100 micro g/L plasma selenium. Mean whole blood selenium declined 20% from the 1977 and 1979 surveys (mean whole blood selenium concentration, 153 micro g/L) to the 1987, 1988 and 2002 surveys (mean whole blood selenium concentration, 122 micro g/L). Plasma selenium was higher in men (P = 0.01), and increased with age in both men and women (P = 0.008). CONCLUSIONS In healthy South Australian adults sampled from 1977 to 2002, whole blood and plasma selenium concentrations were above those reported for most other countries and in most previous Australian studies, notwithstanding an apparent decline in selenium status from the late 1970s to the late 1980s.