What is selenium’s effect on cardiovascular disease risk?
Chen et al say that “oxidative stress, redox signaling, endothelial activation, and inflammation contribute to atherosclerosis and myocardial injury”. So, there is a mechanistic rationale for selenium to have a cardioprotective effect. “Selenium-dependent enzymes provide a plausible connection because glutathione peroxidases and thioredoxin reductases participate in peroxide reduction and redox regulation” [Chen 2026].
Are selenium status and cardiovascular disease related?
Generally, observational studies show low selenium status associated with increased risk of cardiovascular diseases. However, interventional studies have not shown clearly that selenium supplementation reduces the risk of cardiovascular diseases [Chen 2026].
Chen et al analyzed the relevant research for the period 2005-2026. They concluded that there is not enough evidence to support a program of universal selenium supplement for protection against cardiovascular disease [Chen 2026].
- Low selenium status can result in increased risk of cardiovascular disease development; increasing the selenium intake may be beneficial.
- For individuals with adequate selenium status, additional intake may provide little benefit.
- In individuals with high selenium status, there may be metabolic disturbances of glucose metabolism, blood lipids, and blood pressure.
Given this background, Chen et al adopted the idea put forward by Urbano et al [2026]: it makes more sense to focus on the individual’s or the population’s selenium status rather than on the individual’s or the population’s selenium intake.
Similarly, in 2021, Prof Lutz Schomburg said: “Selenium substitution is strongly recommended for chronic or acute deficiency whereas supplementation to healthy subjects with sufficiently high baseline levels does not appear to be warranted”.
Is there a U-shaped relationship between selenium status and cardiovascular diseases?
In their 2026 review, Chen et al summarized the findings of the 2021 observational NHANES study [Tan 2021]. This observational study showed that serum selenium status has a U-shaped relationship with cardiovascular mortality. The bottom of the U was located at 150–160 mcg/L.
Note: NHANES = National Health and Nutrition Examination Survey. In the United States, NHANES “collects data on the prevalence of chronic and infectious diseases and conditions and on risk factors including nutritional status.
However, Chen et al do not propose selenium status of 150–160 mcg/L as a therapeutic target.
Elsewhere, Larsen et al have suggested serum selenium status of approximately 125 mcg/L as an appropriate target. They base their reasoning on the fact that the status of selenoprotein P plateaus at this level [Larsen 2024].
Note: Selenoprotein P is the primary selenium-transport protein in the body. SELENOP delivers selenium to tissues and supports antioxidant defenses, thyroid hormone metabolism, and cellular protection. Adequate SELENOP function may protect against cardiovascular disorders.
What is the relationship between selenium status and cardiovascular mortality?
Cui et al reported the findings of a review of 9 observational cohort studies comprising 41,548 participants and 4,128 cardiovascular deaths. They found that each 1-standard-deviation increase in selenium status was associated with about 11% lower cardiovascular mortality. However, Cui et al do not report a mean selenium status and the extent of the standard deviation for the 9 studies.
What did the KiSel-10 randomized controlled trial show?
Alehagen et al reported that supplementation – 200 mcg/day selenium yeast plus 200 mg/day Coenzyme Q10 – significantly reduced cardiovascular mortality in elderly Swedes low in selenium. However, we cannot attribute the reduced mortality to the selenium supplementation alone [Alehagen 2025].
Conclusion: Selenium and Cardiovascular Diseases
It makes more sense to focus on selenium status than on selenium intake.
Selenium supplementation of selenium-replete individuals is not warranted.
Supplementary selenium may benefit individuals low in selenium.
The optimal selenium concentration in blood seems to lie at or around 125 mcg/L.
Sources
Alehagen U, Aaseth JO, Schomburg L, Opstad TB, Larsson A, Alexander J. Selenium and Coenzyme Q10 supplementation and sex differences in cardiovascular mortality results from a prospective randomized double-blind placebo-controlled trial in elderly people low in selenium. Antioxidants (Basel). 2025 Jun 5;14(6):685.
Chen H, Jin S, Yuan X, Zhong X, Xiao J, Liao J and Zeng X. Selenium nutritional status and cardiovascular diseases: mechanisms of cardioprotection and 21 years of global research trends in precision prevention (2005–2026). Front. Nutr. 2026;13:1920059.
Cui Z, Xie R, Lu X, Schomburg L, Brenner H, Schöttker B. Associations of selenium status with all-cause and cause-specific mortality: a systematic review and meta-analysis of cohort studies. Redox Biol. 2025 Sep;85:103755.
Larsen C, Winther KH, Cramon PK, Rasmussen ÅK, Feldt-Rasmusssen U, Knudsen NJ, Bjorner JB, Schomburg L, Demircan K, Chillon TS, Gram J, Hansen SG, Brandt F, Nygaard B, Watt T, Hegedus L, Bonnema SJ. Selenium supplementation and placebo are equally effective in improving quality of life in patients with hypothyroidism. Eur Thyroid J. 2024 Feb 5;13(1):e230175.
Schomburg L. Selenium deficiency due to diet, pregnancy, severe illness, or covid-19—a preventable trigger for autoimmune disease. International Journal of Molecular Sciences. 2021;22(16):8532.
Tan QH, Huang YQ, Liu XC, Liu L, Lo K, Chen JY, Feng YQ. A U-Shaped relationship between selenium concentrations and all-cause or cardiovascular mortality in patients with hypertension. Front Cardiovasc Med. 2021 Jul 30;8:671618.
Urbano T, Wise LA, Fiore G, Vinceti M, Filippini T. Effects of selenium administration on blood lipids: a systematic review and dose-response meta-analysis of experimental human studies. Nutr Rev. 2026 Mar 1;84(3):551-570.
The information in this review article is not medical advice. Readers should not use this information as medical advice.