Selenium - RBC

Introduction

As a Nurse Practitioner with an autonomous practice in Florida, it is vital to educate patients on the significance of biomarkers in functional medicine. One such essential biomarker is Selenium – RBC, which plays a crucial role in various physiological functions. This article will delve into the background, discussion, clinical implications, and factors affecting selenium levels in the body, providing patients with a comprehensive understanding of this indispensable nutrient.

Background of Selenium

Selenium is an essential trace element needed for numerous biological processes. It is incorporated into selenoproteins, which are vital for antioxidant activity, thyroid hormone metabolism, immune function, inflammation control, and reproductive health. Selenium is particularly important for its role in forming glutathione peroxidase, an antioxidant enzyme that protects cell membranes and lipids from oxidative damage. This protection is crucial in preventing chronic diseases such as atherosclerosis, cardiovascular disease, renal disease, and cancer.

Discussion: Selenium – RBC as a Biomarker

The Selenium – RBC test measures the selenium content within red blood cells, providing an accurate reflection of the body’s selenium status. Approximately 75% of selenium in whole blood is found in the plasma/serum component, with red blood cell selenium levels offering insight into long-term selenium exposure and tissue stores. The measurement can be categorized as serum/plasma, whole blood, or red blood cell.

Selenium intake of approximately 50 µg/L (RDA) corresponds to plasma selenium levels of around 100 µg/L. Dietary sources of selenium include plant foods, meat, and seafood. However, the selenium content in plants depends on soil selenium levels, which vary across different regions. For instance, the soil in the midwestern states of Nebraska and North and South Dakota is rich in selenium, while the southeast coastal area soil is low, often leading to selenium insufficiency.

Clinical Implications of Selenium Levels

Low Selenium Levels and Deficiency

Low selenium levels in the blood, indicative of selenium deficiency, can result from dietary insufficiency, especially in areas with selenium-deficient soil, parenteral nutrition without selenium for an extended period, genetic factors, and general malnutrition. Selenium deficiency has significant clinical implications, including:

• Atherosclerosis: Selenium deficiency impairs antioxidant systems that protect lipids such as LDL cholesterol from oxidation, contributing to atherogenic processes.
  
• Cardiac Dysfunction: Deficiency can lead to cardiomyopathy, congestive heart failure, and atherosclerotic disease.
  
• Cell Membrane Damage and Hemolytic Anemia: Reduced antioxidant enzymes like glutathione peroxidases due to selenium deficiency can damage cell membranes, leading to hemolytic anemia.
  
• Chronic Diseases: Low selenium levels contribute to oxidative damage, implicated in chronic diseases such as kidney disease, heart disease, cancer, and dementia.
  
• Heavy Metal Toxicity: Selenium helps protect cells from Heavy Metals like mercury and lead, potentially preventing neurotoxicity and dysfunction.
  
  

High Selenium Levels and Toxicity

Elevated levels of serum selenium often result from excessive supplementation or industrial exposure. The clinical implications of high selenium levels include:

• Blood Glucose Dysregulation: Excess selenium may disrupt blood sugar regulation if serum levels exceed optimal levels.
  
• Thyroid Dysfunction: High selenium can interfere with thyroid function, affecting feedback systems and reducing T3 production.
  
  

Interfering Factors and Drug Associations

Various factors can interfere with selenium levels in the body. Some medications and conditions may either decrease or increase selenium levels. For instance, certain medications used to treat hyperthyroidism or conditions causing malabsorption can lead to decreased selenium levels. On the other hand, some supplements and medications, when taken excessively, may contribute to elevated selenium levels.

Ranges and When to Test

The standard range for Selenium – RBC in the U.S. is 120.00 – 300.00 µg/L, with the optimal range being 135.00 – 255.00 µg/L. Testing is recommended to determine selenium levels in the body, particularly in individuals at risk of deficiency or toxicity. This includes people living in selenium-deficient areas, those receiving parenteral nutrition, individuals with chronic diseases, and those with potential industrial exposure to selenium.

Conclusion

Selenium is an essential nutrient that plays a pivotal role in maintaining health through its involvement in antioxidant defense, thyroid function, and immune regulation. Understanding the ranges and clinical implications of Selenium – RBC levels helps in identifying and managing both deficiencies and toxicities effectively.

As a functional medicine telehealth provider in Florida, integrating evidence-based therapies with IV Therapy medical care services—where micronutrient optimization and antioxidant support are often impacted—we offer patients a regenerative, preventive framework to rebuild resilience and optimize wellness. Call (904) 799-2531 or schedule online to request your personalized micronutrient and metabolic health assessment.

Further Reading

1. Rayman MP. “Selenium and Human Health.” Lancet. 2012;379(9822):1256–1268. https://pubmed.ncbi.nlm.nih.gov/22381431/
   
2. Fairweather-Tait SJ, Bao Y, Broadley MR, et al. “Selenium in Human Health and Disease.” Antioxid Redox Signal. 2011;14(7):1337–1383. https://pubmed.ncbi.nlm.nih.gov/20976983/
3. Brozmanová J, Lisková V, Paulíková I, Tóthová L. “Selenium: A Double-Edged Sword for Defense and Offence in Cancer.” Arch Toxicol. 2010;84(10):813–838. https://pubmed.ncbi.nlm.nih.gov/20652276/