Can a deficiency of selenium lead to more than 40 diseases?

There is generally no basis for the claim that "deficiency of selenium causes more than 40 diseases." Under normal circumstances, mild selenium deficiency usually does not lead to disease; however, severe selenium deficiency may potentially cause illness. Detailed analysis is as follows:

Selenium is an essential trace element for the human body, crucial for maintaining the immune system, antioxidant defense system, and thyroid function. Individuals who do not consume sufficient selenium-containing foods may develop mild selenium deficiency, which typically presents with symptoms such as slightly dry and dull skin or mild fatigue. These symptoms generally do not cause significant harm to the body and therefore usually do not lead to disease. In such cases, selenium deficiency can be confirmed through medical tests such as serological and dietary assessments, and appropriate selenium supplementation can be undertaken under medical guidance via dietary or pharmaceutical means.

Severe selenium deficiency may result from factors such as environmental pollution, an unbalanced diet, excessive tobacco and alcohol consumption, and long-term unhealthy lifestyle habits. Patients may experience significant symptoms such as dry, flaky skin and hair loss. Additionally, severe selenium deficiency may reduce nervous system sensitivity, leading to symptoms like numbness and pain in the limbs. At this stage, medications such as selenium yeast tablets, sodium selenite tablets, and selenium and lycium barbarum liver-nourishing mixtures may be used under medical supervision for treatment.

In daily life, it is important to ensure adequate selenium intake to maintain good health and undergo regular medical check-ups to monitor one's health status.