Selenium

AvoidCautionSuggested

4 studies · 3 recommendations

Last updated: February 25, 2026

Avoid2 studies

Selenium supplementation linked to increased prostate cancer mortality in dose-dependent manner

A prospective cohort study of 4,459 men with nonmetastatic prostate cancer found selenium supplementation at ≥140 μg/day more than doubled prostate cancer mortality risk (HR 2.60, 95% CI 1.44–4.70) compared with nonusers, with a significant dose-response trend (P = .001). Lower doses showed non-significant elevations in risk (HR 1.18 for 1–24 μg/day; HR 1.33 for 25–139 μg/day). A systematic review spanning 23 years of literature (1990–2013) independently concluded that selenium supplements should not be used for prostate cancer prevention, with higher doses potentially worsening prognosis. Across both studies — one cohort and one systematic review — the evidence consistently points to harm rather than benefit from selenium supplementation in men with or at risk for prostate cancer.

Evidence

Selenium Supplementation and Prostate Cancer Mortality

Authors: Chan, June M, DuPre, Natalie, Kenfield, Stacey A, L Giovannucci, Edward, Stampfer, Meir J, Van Blarigan, Erin L

Published: December 12, 2014

A prospective cohort of 4,459 men with nonmetastatic prostate cancer from the Health Professionals Follow-Up Study was followed from 1988 through 2010 (median follow-up 8.9 years). During follow-up, 965 deaths occurred, including 226 (23.4%) from prostate cancer. Crude prostate cancer death rates per 1,000 person-years were 5.6 among selenium nonusers versus 10.5 among men consuming ≥140 μg/day. In multivariable-adjusted Cox models, selenium intake of 1–24 μg/day (HR 1.18, 95% CI 0.73–1.91), 25–139 μg/day (HR 1.33, 95% CI 0.77–2.30), and ≥140 μg/day (HR 2.60, 95% CI 1.44–4.70) showed increasing prostate cancer mortality risk compared with nonusers (P trend = .001). No statistically significant associations were found with biochemical recurrence, cardiovascular mortality, or overall mortality.

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Prostate cancer and the influence of dietary factors and supplements: a systematic review

Authors: Mandair, D, Rossi, R, Pericleous, M, Whyand, T, Caplin, M

Published: January 1, 2007

A systematic review of PubMed literature from 1990 to 2013 concluded that selenium supplements cannot be advocated for the prevention of prostate cancer. More concerning, the review found that higher doses of selenium may be associated with a worse prognosis. This finding emerged from synthesizing multiple studies across the 23-year review period, covering epidemiological and interventional research on dietary factors and prostate cancer. The evidence was sufficient for the authors to explicitly recommend against selenium supplementation for prostate cancer prevention.

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Caution1 studies

Selenium supplements show no benefit for prostate cancer prevention

Despite earlier hypotheses suggesting selenium could reduce prostate cancer risk, high-quality randomized trials have not confirmed any protective effect. An initial hypothesis from the NPCT trial that men with low baseline selenium levels might benefit was not confirmed by subsequent larger trials with low risk of bias.

Evidence

Selenium for preventing cancer.

Authors: Brinkman, M, Crespi, Cm, D'Amico, Roberto, DEL GIOVANE, Cinzia, Dennert, G, Horneber, M, Vinceti, Marco, Zeegers, Mp, Zwahlen, M

Published: January 1, 2014

Systematic review including 55 observational studies (>1,100,000 participants) and 8 RCTs (44,743 participants). Observational data suggested lower prostate cancer risk with higher selenium exposure, but RCTs showed an imprecise overall effect (RR 0.90, 95% CI 0.71 to 1.14, 4 studies, N = 19,110). When restricted to trials with low risk of bias, selenium supplementation showed no effect on prostate cancer risk (RR 1.02, 95% CI 0.90 to 1.14, 3 studies, N = 18,183). The hypothesis that individuals with lowest baseline selenium levels could reduce prostate cancer risk through supplementation was not confirmed by subsequent trials.

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Suggested1 studies

Higher selenium levels linked to lower risk of high-grade prostate cancer

In a population with relatively low selenium intake, higher plasma selenium and selenoprotein P levels were associated with reduced risk of high-grade prostate cancer. While selenium was not associated with total or advanced prostate cancer risk, the specific association with high-grade disease suggests potential benefit for aggressive disease prevention.

Evidence

Selenium status and risk of prostate cancer in a Danish population

Authors: Christensen, Jane, Friis, Søren, Larsen, Erik Huusfeldt, Larsen, Signe B., Olsen, Anja, Outzen, Malene, Overvad, Kim, Tjønneland, Anne

Published: January 1, 2016

Nested case-control study within the Danish 'Diet, Cancer and Health' cohort of 27,179 men identified 784 prostate cancer cases matched to 784 controls. Among cases, 525 had advanced disease and 170 had high-grade disease. Higher plasma selenium was associated with lower risk of high-grade prostate cancer (HR 0.77; 95% CI 0.64-0.94; P=0.009). Higher selenoprotein P levels similarly showed reduced high-grade disease risk (HR 0.85; 95% CI 0.74-0.97; P=0.01). Plasma selenium was also associated with lower all-cause mortality among prostate cancer cases (HR 0.92; 95% CI 0.85-1.00; P=0.04). No significant association was observed for total or advanced prostate cancer risk. During follow-up through 2012, 305 cases died, of whom 212 died from prostate cancer.

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