What age should you take selenium? Understanding your nutritional needs

The official Recommended Dietary Allowance (RDA) for selenium is 55 micrograms daily for most adults over 19. Deciding what age should you take selenium involves understanding that while the standard need is stable, factors like diet, geography, and specific health concerns can influence supplementation, particularly with age.

Quick Summary

Most healthy adults aged 19 and older have a consistent daily requirement of 55 mcg of selenium, which is typically met through a balanced diet. Supplementation is primarily for those with a confirmed deficiency or specific health conditions, not for general anti-aging purposes.

Key Points

• Age-Related Needs: The RDA for selenium is consistent at 55 mcg daily for adults 19 and older, but absorption may be affected by health changes in later years.

• Diet First: Most healthy adults in selenium-rich regions, like the US, can meet their needs through food sources alone.

• Risk Groups: Individuals on restrictive diets (vegan/vegetarian), those with GI issues, or people living in areas with poor soil quality may be at higher risk for deficiency.

• Potential Benefits: Selenium acts as an antioxidant, supports thyroid function, and boosts the immune system, all of which are important for healthy aging.

• Supplementation Cautions: High-dose supplements can be toxic and should only be taken under medical supervision, especially for individuals with confirmed deficiency.

• Recognize Toxicity: Watch for signs of selenosis, such as hair loss, nail brittleness, fatigue, or a garlic-like breath odor, which indicate excessive intake.

Understanding Selenium Needs Across the Lifespan

Selenium is an essential trace mineral vital for numerous bodily functions, including thyroid hormone metabolism, DNA synthesis, and immune system health. While the daily recommendation remains stable for adults, the risk of deficiency can increase with age, especially in older adults.

Daily Recommended Allowance (RDA) by Age Group

The National Institutes of Health (NIH) provides clear guidelines on daily selenium intake:

• Infants (0-6 months): 15 mcg
• Infants (7-12 months): 20 mcg
• Children (1-3 years): 20 mcg
• Children (4-8 years): 30 mcg
• Children (9-13 years): 40 mcg
• Adolescents and Adults (14+ years): 55 mcg
• Pregnant females: 60 mcg
• Lactating females: 70 mcg

As seen, the RDA for a healthy adult is 55 micrograms per day, and this recommendation does not change for seniors. The focus shifts not to a different dosage but to ensuring adequate intake, as seniors may face increased risks of deficiency due to changes in diet or absorption.

The Role of Selenium in Healthy Aging

Antioxidant Powerhouse

Selenium is a key component of selenoproteins, which act as powerful antioxidants. These antioxidants protect cells from oxidative stress caused by free radicals, unstable atoms that can damage cells and DNA. As we age, our body's natural antioxidant defenses can weaken, making adequate selenium intake even more important for maintaining cellular health and reducing inflammation.

Supporting Thyroid Health

The thyroid gland has the highest concentration of selenium in the body. Selenium is essential for the function of enzymes involved in converting thyroid hormones into their active forms. Proper thyroid function is crucial for metabolism and energy levels, which are often affected in the aging process.

Boosting Immune Function

Selenium plays a significant role in maintaining a healthy immune system. A deficiency can impair immune responses, increasing susceptibility to infections and other illnesses. For older adults with a weakened immune system, ensuring sufficient selenium intake can be a key component of maintaining health.

Cognitive Function and Brain Health

Some research suggests that declining serum selenium levels with age may be linked to age-related cognitive decline. While supplementation has shown mixed results in clinical trials for preventing dementia, preclinical studies suggest selenoproteins are vital for brain health and protecting against oxidative damage. More research is needed to fully understand the connection.

Factors Influencing the Need for Selenium Supplementation

Dietary Intake and Soil Quality

For most people in the United States and Canada, getting enough selenium from food is straightforward due to selenium-rich soil. However, individuals in regions with selenium-poor soil (e.g., parts of Europe, China, and New Zealand) or those following restricted diets, like vegan or vegetarian, may be at higher risk of deficiency.

Health Conditions and Absorption

Certain health conditions can interfere with the body's ability to absorb nutrients. For example, individuals with gastrointestinal disorders like Crohn's disease or ulcerative colitis may struggle with proper selenium absorption. Similarly, those on long-term parenteral nutrition or undergoing certain medical treatments may need medical supervision for supplementation.

Food Sources vs. Supplements: A Comparison

The best source of selenium is through a balanced diet. Supplements should be reserved for those who cannot meet their needs through food alone.

Feature	Food Sources	Supplements
Selenium Content	Varies widely based on soil, animal diet, and specific food item.	Standardized, allowing for precise dosage control.
Forms of Selenium	Primarily organic forms like selenomethionine, highly bioavailable.	Can be organic (selenomethionine) or inorganic (selenite), with varying absorption.
Nutritional Synergy	Comes with other vitamins, minerals, and nutrients that work synergistically.	Isolated nutrient; lacks the holistic benefits of whole foods.
Regulation	Natural intake is generally self-regulated by dietary patterns.	Requires caution to avoid exceeding the Tolerable Upper Intake Level (UL) of 400 mcg.
Who Benefits	Nearly everyone aiming for a balanced diet.	Individuals with confirmed deficiency, malabsorption issues, or living in low-selenium areas, under medical supervision.

Some of the best dietary sources of selenium include Brazil nuts, yellowfin tuna, halibut, sardines, shrimp, beef, chicken, ham, eggs, brown rice, cottage cheese, and sunflower seeds.

Risks and Safety of Excessive Selenium Intake

While essential, selenium has a narrow margin between beneficial and toxic levels. The Tolerable Upper Intake Level (UL) for adults is 400 micrograms per day. Excessive intake, a condition called selenosis, can lead to adverse health effects:

• Hair and nail problems: Brittleness and loss are common early signs.
• Gastrointestinal issues: Nausea, vomiting, and diarrhea.
• Nervous system effects: Fatigue, irritability, and mild nerve damage.
• Garlic breath: A distinct odor is often a telltale sign.

Long-term use of high-dose supplements, particularly over 200 mcg, has also been linked to an increased risk of type 2 diabetes and high cholesterol in some studies, underscoring the importance of caution with supplementation.

For more detailed information on dosage recommendations and safety, consult resources like the NIH Office of Dietary Supplements.

Conclusion: A Personalized Approach to Selenium

For most healthy adults, including seniors, the best approach is to obtain selenium from nutrient-rich foods rather than relying on supplements. Factors like where your food is grown, your dietary habits, and your overall health status play a significant role. Supplementation should only be considered under the guidance of a healthcare provider, who can assess your individual risk factors and, if necessary, order a blood test to determine your selenium levels. By prioritizing a balanced diet and consulting with a professional, you can ensure adequate selenium intake for healthy aging while avoiding the risks associated with excess amounts. Proper management of this essential mineral is a key component of maintaining optimal wellness throughout life.

Frequently Asked Questions

At what age should you consider taking a selenium supplement?

You should not consider taking a selenium supplement based solely on age. Instead, consult a healthcare provider if you have risk factors for deficiency, such as a restricted diet or a gastrointestinal condition, regardless of your age.

Can older adults become deficient in selenium?

Yes, older adults can be at a higher risk of selenium deficiency, as serum levels can decline with age. Factors like poor diet, malabsorption issues, or living in low-selenium regions contribute to this risk.

How can I tell if my selenium levels are low?

Common symptoms of selenium deficiency include fatigue, hair loss, a weakened immune system, and muscle weakness. However, these are non-specific and a blood test by a doctor is the only definitive way to determine your status.

What foods are rich in selenium?

Excellent food sources of selenium include Brazil nuts, fish like yellowfin tuna and halibut, seafood, red meat, poultry, eggs, whole grains, and dairy products like cottage cheese.

Is it possible to get too much selenium from my diet?

While unlikely from a balanced diet, it is possible to ingest toxic levels of selenium, especially from overconsuming sources like Brazil nuts, which are extremely potent. A single serving of Brazil nuts can exceed the Tolerable Upper Intake Level (UL).

How does selenium benefit older adults?

In older adults, selenium's antioxidant properties help reduce oxidative stress, which contributes to aging. It also supports immune function, aids thyroid health, and may play a role in cognitive health, though more research is ongoing.

Can selenium supplements help prevent dementia?

Research has yielded conflicting results regarding selenium supplementation and dementia prevention, particularly in individuals with adequate baseline levels. While low selenium is linked to cognitive decline, supplements are not a proven preventative measure.