Iodine has been in the limelight due to its role in enhancing the functionality of the reproductive system and its contribution to hormone production in thyrocytes. This is interesting however as its effects on the immune system have been relatively neglected – that is until now. Iodine supplements can be administered when levels of iodine are low in the body to heal various conditions.
In the recent volume of Frontiers in Immunology, there is a fusion of several ideas concerning iodine, thyroglobulin (TG), and functioning of the human immune system. The aim of this paper is to elaborate and interpret those findings in the context of what other researchers had said about the utility of iodine for the immune system in the context of the human body.
Iodine and Immune Function
Thyroid hormones, which are vital for growth, development, and metabolic homeostasis, are influenced by the presence of iodine in the body. It is essential to have these hormones regulated within the body through the production of the thyroid.
Any changes in this particular area caused by iodine deficiency will influence the synthesis of thyroid hormones which will definitely lead to deficiency and various health complications such as immune deficiency and greater vulnerability to diseases and infections.
This article addresses some of the impacts of iodine supplementation on immune function with a special focus on thyroid hormones and immune cells. It is hoped that these interactions will enhance understanding of the importance of adequate iodine levels for health in general.
Iodine and Immune Cells: A Complex Relationship
In their study Bilal et al, sought to explain the interactions between iodine and human immune cells. Their investigations on leukocytes, white blood cells formed within the bone marrow and other lymphatic tissue, that are involved in the immune response, bore positive results.
Researchers discovered the presence of mRNA for iodide transporters such as the sodium-iodide symporter (NIS) and Pendrin, along with thyroid-related proteins like thyroglobulin (TG) and thyroid peroxidase (TPO), among leukocytes.
Quite remarkably, pendrin and TPO were shown to increase on expression when leukocytes were activated while TG expression was reduced. This indicates changes in gene expression related to iodine metabolism and further confirms the role of iodine in the immune functions.
How Iodine Influences Immune Function
One of the important considerations made in the course of this investigation was sodium iodide therapy. Elemental iodine in its molecular form (I2) has shown to exert very pronounced apoptosis inducing and antibacterial properties.
Correspondingly, a number of investigations have supported the antibacterial activity of iodide salts along with their strong gene modifying effect especially of chemokines which serve to guide immune cells to places of tissue damage or infection.
There are also pro-inflammatory and anti-inflammatory cytokines that were also found to be upregulated after Nal. This shows that iodine does have a role in immune responses, but a more complex one than simply producing more immunoglobulins. A large number of participants in the study indicated that while leukocytes do contain small amounts of T4 and T3 after exposure to TG, bulk iodine action does not involve new thyroid hormone formation.
Iodine Deficiency and Immune Function
Iodine deficiency is a major threat to global public health status with a prevalence of roughly 2 billion including school-aged children. The deficiency has also been associated with decreased immune response thereby increasing the chances of infections in such individuals. Immune response is indeed a comprehensive approach towards the body against any kind of pathogen and, more importantly, it is a critical process involved in the occurrence and spread of cancer.
It is found that an increased prevalence of iodine deficiency has also been shown to be associated with certain types of cancer, breast cancer being one of them. Iodine supplementation has been shown through research to help people have improved immune response and decreased chances of infections especially those with an iodine deficiency.
It is therefore evident that by treating iodine deficiency, we can improve immune response abilities and hence help in decreasing the incidences and complications of iodine deficiency disorders.
Immune Cells and Thyroid Hormone Regulation
Another interesting finding from the research is that the thyroid gland plays a crucial role in the production of thyroid hormones, which are regulated by immune cells. When leukocytes were cultured with TG, cells secreted substantial amounts of T4 and T3 hormones, possibly contributing to the levels of these hormones in tissues and peripheral blood.
This observation raises the possibility that immune cells may help to regulate the levels of thyroid hormones available in the body at the tissue level – leading to a better understanding of the relationship between the immune system and interceding body functions.
Implications of Iodine Deficiency for Health and Disease
The ability of iodine to inhibit immune function mechanisms has important health consequences, especially for those persons who have insufficient iodine in their diet. Iodine supplementation has been shown to alleviate symptoms of fibrocystic breast disease, a benign condition prevalent in women. Iodine deficiency is one of the global deficiencies as it affects nearly 2 billion people and is known to cause various thyroid-related problems, such as hypothyroidism and goiter.
On a broader note, this theory postulates that excessive iodine deficit may dislocate some previously appropriate mechanisms of human immune, hence exposure to many immune-associated ailments and infectious diseases, This shifts our focus towards not only considering iodine intake within normal limits for yo thyroid but it also for a healthy immune system.
Iodine Supplementation and Pregnancy
This study may have relationships with pregnant women because of how their iodine demand increases during pregnancy, or how even the slightest of deficiencies in iodine can cause reproductive difficulties during child gestation. Potassium iodide is commonly used in dietary supplements to ensure adequate iodine intake during pregnancy. This is bad as adequate iodine levels are crucial for optimal fetal brain development and avoiding reproductive issues.
As iodine is critical for immune system support, the bone marrow can be affected by high levels of iodine deficiency and cause pregnancy-related issues via a change in immune activity.
Conclusion
This study reveals a hitherto unknown role of iodine in the immune system and indicates a rather intricate relationship between iodine, immune cells and thyroid hormones. Iodine supplementation can suppress the expression of vascular endothelial growth factor (VEGF), potentially reducing tumor growth and improving immune response. The results of the study suggest that iodine helps to form thyroid hormones but also participates in the immunity directly.
Such a two-sided approach, however, firmly establishes the necessity of having sufficient iodine to the body for optimal physiological activity, more so in parts of the world where iodine deficiency is common.
With evolving knowledge on how iodine works alongside the immune system, there can be those who may need iodine supplementation in a bid to treat immune related complications. This work provides a strong basis for expanding research on the other health consequences related to iodine and the suggestions of this element in improved immune response capability.
