In this Article
- What other names is Selenium known by?
- What is Selenium?
- How does Selenium work?
- Are there safety concerns?
- Are there any interactions with medications?
- Dosing considerations for Selenium.
Selenium is POSSIBLY UNSAFE when taken by mouth in high doses or for long-term. Taking doses above 400 mcg can increase the risk of developing selenium toxicity. Taking lower doses long-term can increase the risk of developing diabetes. High doses of selenium can cause significant side effects including nausea, vomiting, nail changes, loss of energy, and irritability. Poisoning from long-term use is similar to arsenic poisoning, with symptoms including hair loss, white horizontal streaking on fingernails, nail inflammation, fatigue, irritability, nausea, vomiting, garlic breath odor, and a metallic taste.
Selenium can also cause muscle tenderness, tremor, lightheadedness, facial flushing, blood clotting problems, liver and kidney problems, and other side effects.
Special Precautions & Warnings:Children: Selenium is POSSIBLY SAFE when taken by mouth appropriately. Selenium seems to be safe when used in the short-term in doses below 45 mcg daily for infants up to age 6 months, 60 mcg daily for infants 7 to 12 months, 90 mcg daily for children 1 to 3 years, 150 mcg daily for children 4 to 8 years, 280 mcg daily for children 9 to 13 years, and 400 mcg daily for children age 14 years and older.
Pregnancy and breast-feeding: Selenium use is POSSIBLY SAFE during pregnancy and breast-feeding when used short-term in amounts that are not above 400 mcg daily. Selenium is POSSIBLY UNSAFE in pregnancy and breastfeeding when taking by mouth in doses above 400 mcg daily, as this might cause toxicity, and in HIV-positive women, as this might increase virus levels in breast milk.
Autoimmune diseases: Selenium might stimulate the immune system. In theory, selenium might make autoimmune disease worse by stimulating the activity of the disease. People with autoimmune diseases such as multiple sclerosis, systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and other should avoid taking selenium supplements.
Hemodialysis: Blood levels of selenium can be low in people undergoing hemodialysis. Using a dialysis solution with selenium might increase selenium levels, but selenium supplementation might be needed for some people.
Under-active thyroid (hypothyroidism): Taking selenium can worsen hypothyroidism especially in people with iodine deficiency. In this case, you should take iodine along with selenium. Check with your healthcare provider.
Fertility problems in men: Selenium might decrease the ability of sperm to move, which could reduce fertility. If you are trying to father a child, don't take selenium supplements.
Skin cancer: Long-term use of selenium supplements might slightly increase the risk of skin cancer recurrence, but this is controversial. Until more is known about the possible increase in skin cancer risk, avoid long-term use of selenium supplements if you have ever had skin cancer.
Surgery: Selenium might increase the risk of bleeding during and after surgery. Stop taking selenium at least 2 weeks before a scheduled surgery.
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