Selenium is a mineral. It is found in the soil and in marine bivalves (such as oysters). It is found in many Foods. It promotes overall health in humans and is thus an essential element. Selenium produces toxin in the Body if taken in excess. A moderate amount is necessary for the maintaining the overall health. It regulates thyroid hormones and supports healthy Immune System. It is an antioxidant. It prevents the Cell damage from free radicals.
Selenium prevents and cures Cancer. Yes it does. Trust me. And. The trick to cure cancer, is, just take an all fruit diet with selenium.

Level of Selenium in the Body
0.07 to 0.1 mcg/dl

Daily Requirement of Selenium in the Body
55 micro gram per day ( mcg/d )

Functions of Selenium in the Body
Prevent Cancers
Essential for Mental health
Prevent Cardiovascular Disease
Required for Heavy metal detoxification
Produce Thyroid Hormone, called Tetraiodothyronine
Make antioxidant enzymes, which prevents Cell damage
Protect the Body from the poisonous effects of heavy metals and other harmful substances

Benefits of Selenium in the Body
Treats Asthma
Heals Burn injuries
Fights Prostate Cancer
Reduces Malabsorption
Prevents Keshan Disease
Improve the Immune System
Lowers the Risk of Cardiomyopathy
Cures Intracranial Pressure Symptoms
Increase the HDL Cholesterol and decrease the LDL cholesterol for a healthy Heart.
 
Effects of Deficiency of Selenium in the Body
Cancer
Arthritis
Miscarriage
Fibromyalgia
Heart Disease
Hypothyroidism
Mental Fatigue
General Fatigue
Reproductive Disorders
Viral and Bacterial Infections

Effects of Excess Selenium in the Body
Nausea
Fatigue
Vomiting
Hair loss
Skin rash
Irritability
Nail changes
Loss of energy
Facial flushing
Muscle tenderness
Mild nerve damage
Nail inflammation
Garlic-breath odor
Brittle hair and nails
Gastrointestinal upset
Blood clotting problems
Liver and Kidney problems