Selenium is a trace element that plays a crucial role in the thyroid gland and the production of thyroid hormones. It also protects the thyroid from damage caused by oxidative stress, as highlighted in a review article published in Archives of Endocrinology and Metabolism. But how much selenium do we actually need for the thyroid and the many other selenium-dependent functions in the body?

- especially in older adults

When blood levels of vitamin B12 are at the low end of the normal range, there's no guarantee that there is enough to support DNA synthesis, red blood cell formation, and nerve tissue maintenance. The official reference values may be particularly problematic for older adults, who, according to an American study, have an increased risk of developing cognitive decline and dementia.

Asthma is characterized by chronic inflammation and oxidative stress. Smoking, air pollution, heavy metals, and various environmental allergens also increase the risk. However, it appears that an optimal level of selenium and manganese in the blood can potentially improve health and survival in asthma patients. This is partly because selenium and manganese function as antioxidants that counteract oxidative stress and chronic inflammation. At the same time, selenium helps eliminate heavy metals, according to a study published in Scientific Reports.

The carotid artery supplies the brain with blood, and narrowing can lead to debilitating and life-threatening strokes. According to a study on middle-aged participants with high blood pressure, a deficiency in vitamin D increases the risk of calcification and narrowing of the carotid artery.

Migraine is one of the most widespread neurological diseases, and it turns out that diet and lifestyle play a significant role. Supplementation with magnesium, vitamin D, Q10, vitamin B2, alpha-lipoic acid, and probiotics may relieve migraines or reduce the number of migraine days, according to a new meta-analysis published in Neurological Sciences. It is also essential to identify which nutrients the individual migraine patient lacks and aim at taking supplements that optimize blood levels of these substances.

Patients with chronic kidney disease (CKD) have an increased risk of both vitamin D deficiency and developing depression. According to a population study published in Frontiers in Nutrition, maintaining optimal vitamin D levels in the blood may reduce the risk of severe depression in these patients.

Several B-vitamins need to be converted into other forms before they are activated for a wide range of functions. However, enzyme defects, alcohol, medication, and aging processes can make this difficult. The form of vitamin D that we produce from the sun or get from supplements is also inactive, and factors like obesity, aging processes, and a lack of certain minerals can make it difficult to make the active form. Conversion of vitamin K1 into vitamin K2 requires a well-functioning gut flora. Optimal utilization of Q10 requires a specific selenium compound. This means that an inability to activate vitamins and Q10 can result in chronic fatigue, many serious diseases, and in the worst case, early death.

Several studies have shown that optimizing your blood vitamin D levels with supplementation reduces the risk of contracting respiratory infections such as COVID-19. A new Hungarian study, published in Nutrients, has also found that very high doses of vitamin D given to hospitalized COVID-19 patients can reduce the risk of prolonged hospital stays and death due to severe complications.