It is estimated that one billion people worldwide lack selenium. This has fatal consequences for public health because it increases the risk of virus infections, thyroid disorders, cardiovascular diseases, cancer, neurological disorders, and involuntary infertility. Adding to that problem is the fact that mercury, a known environmental toxin, throws a wrench into selenium’s different functions. In the following, we have compiled a long list of studies that look closer at the consequences of selenium deficiency and the advantage of optimizing the body’s selenium status with help from supplements.

Hashimoto’s thyroiditis is the most common underlying cause of hypothyroidism. It is characterized by extreme fatigue, weight gain, and a number of other symptoms. Hashimoto’s is an autoimmune condition where antibodies attack the thyroid gland. Many people who get treatment for their disease don’t improve, on the contrary. According to a meta-analysis published in Medicine, however, selenium supplementation appears to be able to reduce the autoimmune reactions and the body’s production of the different antibodies. Selenium helps control the thyroid function but also serves as an antioxidant that protects the thyroid gland against oxidative stress.

Vitamin D deficiency is a common problem among patients with rheumatoid arthritis. However, if their blood levels of vitamin D are high before they start on methotrexate therapy, it lowers their mortality. This was shown in a study published in Nutrients, where the authors looked at vitamin D’s therapeutic properties. Note that the official vitamin D recommendations are too low to optimize blood levels of the nutrient.

Epidemiological studies have shown that relatively high doses of omega-3 fatty acids that are found in oily fish and fish oil supplements have a positive effect on neurodegenerative diseases such as sclerosis, but the underlying mechanisms are not known. A mouse study reveals that one particular omega-3 fatty acid is able to control the immune defense and regulate the inflammatory processes in the central nervous system.

The rate of inflammatory bowel diseases like ulcerous colitis is growing, and diet plays a major role. Even if you eat a healthy diet, it can be a challenge to get enough selenium because of the selenium-depleted soil in our part of the world. Apparently, selenium supplementation can lower the disease activity and improve quality of life in patients with ulcerous colitis.

Autoimmune diseases occur in the wake of chronic inflammation and are the result of the immune defense erroneously attacking the body’s own tissues. Rheumatoid arthritis, psoriasis, sclerosis, and Hashimoto’s disease (that causes hypothyroidism) are all examples of autoimmune diseases that primarily affect women and older people. The diet plays a significant role and according to a study published in The British Medical Journal, supplements of vitamin D and fish oil taken for extended periods can lower the rate of autoimmune diseases. This is useful knowledge because these diseases are on the rise and the medicine that is used to treat them often comes with serious side effects.

Vitamin B12 is important for the development and function of our central nervous system. In the past decades, science has also found similarities between sclerosis and the neurological symptoms that occur in people who lack vitamin B12. In a new study that is published in Cell Reports, scientists have found the molecular relation between vitamin B12 and the function of supportive brain cells.

Vitamin B12 is required for the production of red blood cells, and the importance of the nutrient for the nervous system is often overlooked. Factors like vegan diets, ageing processes, low stomach acid, and use of anti-diabetic medication increase the risk of a vitamin B12 deficiency. Pernicious anemia is a life-threatening autoimmune disease where people are unable to absorb vitamin B12 from their diet. Typical symptoms of the condition are fatigue, poor memory, nerve damage, impaired fertility etc. and because these problems are insidious, it may be difficult to link them to the root cause. Many people are misdiagnosed as being stressed or having dementia. However, according to an article published in MedicalNewsToday, it may have detrimental consequences for your health if the vitamin B12 deficiency is not treated in ample time.