Selenium is considered an essential dietary mineral that helps protect the body from oxidative stress. Plant-based foods are typically the major source of this mineral in the diet, and the exact selenium concentration in a given food is determined by the soil in which it is grown. Although rare in the United States, selenium deficiency is common in China, where the soil is lower in selenium. Scientists estimate one billion individuals worldwide are currently living with a selenium deficiency. Individuals who have Crohn's disease are at an elevated risk of this particular issue, and individuals who are undergoing dialysis are also more likely to develop it.
To prevent a selenium deficiency, doctors recommend individuals consume fifty-five micrograms of selenium each day. Ideally, selenium should be consumed through food instead of supplements. Foods rich in selenium include Brazil nuts, whole-wheat bread, beans, rice, and some types of tuna. Selenium deficiency can be difficult to diagnose, and doctors may use a blood test that measures levels of an enzyme known as glutathione peroxidase. This enzyme needs selenium to function properly, and low enzyme levels may suggest low selenium. In evaluating patients for this nutritional deficiency, doctors will check for the symptoms outlined below.
Weak Immune System
Patients with a selenium deficiency will often present with a weak immune system. When the immune system is weakened, this can result in a greater risk of infection. For example, patients with compromised immune systems may get frequent colds or other respiratory illnesses, and they are also more at risk of pneumonia. They may also exhibit constant fatigue, and may have slow to heal wounds or swollen lymph nodes.
In particular, patients who have cancer or thyroid conditions, including Grave's disease, are already living with weakened immune systems due to these conditions, and they should be especially vigilant about getting adequate selenium in their diet. To check for the possibility of a weakened immune system, doctors can perform a series of blood tests, and they will conduct a physical examination to look for signs of infection.