Does Selenium Cause Side Effects?
Selenium is a trace mineral, meaning that the human body only needs a small amount to function properly. In the United States, most people get plenty of selenium through food. A normal dietary intake is unlikely to cause any side effects for most people. However, a high selenium intake (usually through supplementation) can cause serious side effects.
Serious Selenium Side Effects
Even though it seems like a harmless mineral, selenium can cause some dangerous side effects, especially if too much is taken. Although some of these side effects do not appear to be serious, they can be signs of selenium toxicity. Because selenium toxicity can result in death, you should immediately report any of these side effects to your healthcare provider. These side effects include but are not limited to:
- Nausea, vomiting, and abdominal (stomach) pain
- White, horizontal streaking of the fingernails
- Hair loss
- Hair and nail brittleness
- A metallic taste in the mouth
- "Garlic" breath odor
- Fatigue
- Irritability
- Weight loss
- Muscle tenderness
- Shakiness
- Flushing (redness) of the face
- Heart failure
- Cardiac arrest
- Signs of an allergic reaction, such as:
- A rash
- Itching
- Hives
- Swelling of the mouth or throat
- Wheezing
There is also some concern that high intakes of selenium may increase the risk of
skin cancer,
type 2 diabetes, and male infertility. However, more research is necessary before the full extent of these risks can be determined.
