HSA | FSA CARDS ARE NOW ACCEPTED

Selenium and the SEPP1 Gene: What Your Results Mean for Health and Nutrition

Selenium is a trace mineral that plays an important role in immune function, thyroid hormone regulation, antioxidant defense, and DNA synthesis. SEPP1 is the gene that encodes Selenoprotein P, a primary carrier that moves selenium from the liver to other tissues. Variations in SEPP1 can change how efficiently selenium is transported in the body and may influence circulating selenium levels. Below is a clear explanation of what different genotypes at rs7579 mean and practical, consumer-friendly recommendations to support healthy selenium status.

How SEPP1 and Selenoprotein P Work

Selenoprotein P carries selenium in the blood to organs and tissues that need it, including the brain, thyroid, and immune cells. When SEPP1 function is reduced, tissues may receive less selenium even if dietary intake is unchanged. That can affect the activity of selenoproteins involved in antioxidant protection and thyroid hormone metabolism. Genetics is only one factor that affects selenium status. Diet, soil selenium levels where food was grown, age, health conditions, and medications also matter.

Genetic Interpretation

2 effect alleles (TT) — Two copies of the effect allele

If you have the TT genotype at rs7579 you carry two copies of the effect allele. This variation is associated with lower serum selenium levels. Your SEPP1 gene may produce or utilize Selenoprotein P less efficiently, which can lead to lower circulating selenium compared with other genotypes. This is a genetic predisposition and does not automatically mean you have a selenium deficiency.

Practical points:

  • Focus on selenium rich foods: Brazil nuts in moderation, seafood, lean meats, eggs, and selenium containing vegetables.
  • Consider periodic monitoring of serum selenium or selenoprotein P if you have symptoms suggestive of deficiency or other risk factors.
  • If you choose supplements, use them cautiously and under guidance from your healthcare provider to avoid excessive intake.
1 effect allele (CT) — One copy of the effect allele

With the CT genotype at rs7579 you carry one copy of the effect allele. This genotype is associated with likely lower serum selenium levels, reflecting a moderate influence on how efficiently Selenoprotein P transports selenium from the liver to other tissues.

Practical points:

  • Prioritize selenium rich foods such as Brazil nuts (small portion), seafood, lean meats, eggs, and dairy products.
  • Follow the recommended daily allowance of about 55 micrograms for most adults through diet. Your individual needs may differ.
  • Talk with your healthcare provider before starting supplements because excess selenium can cause toxicity.
0 effect alleles (CC) — No effect alleles

If you have the CC genotype at rs7579 you carry two copies of the non effect allele. This genotype is associated with typical selenium transport and metabolism. Your SEPP1 gene is likely producing Selenoprotein P at levels that support normal selenium delivery to tissues.

Practical points:

  • You are not predisposed to lower selenium levels because of this genetic factor, but diet and environment still affect selenium status.
  • Maintain a balanced diet that includes selenium rich foods to meet the recommended daily allowance of about 55 micrograms for most adults.
  • Consider periodic assessment only if you have medical reasons to check selenium or selenoprotein levels.

Diet Recommendations

  • Eat a variety of selenium rich foods: Brazil nuts, seafood like tuna, shrimp, and salmon, lean meats, poultry, eggs, and dairy.
  • Consume Brazil nuts in moderation. One to three Brazil nuts several times a week is often sufficient to raise selenium intake without exceeding safe limits.
  • Include plant foods that may contain selenium depending on soil: certain grains, beans, and vegetables. Soil selenium varies by region so animal and seafood sources are more reliable for consistent intake.
  • Balance selenium sources with overall diet quality. A varied whole foods diet supports absorption and overall nutrient status.

Supplement Recommendations and Safety

  • Supplements can correct low intake but should be used cautiously only when indicated by diet assessment or testing.
  • Avoid high dose supplements unless prescribed by a healthcare provider. Chronic excess selenium can cause symptoms such as gastrointestinal upset, hair or nail changes, and neurologic effects.
  • If considering a supplement, use a form and dose recommended by your provider. Typical multivitamins contain safe, moderate amounts while targeted selenium supplements should be supervised clinically.

Lifestyle and Monitoring

  • Consider a blood test for serum selenium or selenoprotein P if you have symptoms that could relate to low selenium, are on restrictive diets, or have health conditions that affect absorption.
  • Review medication and supplement lists with your healthcare provider. Some medications and interactions can change selenium status.
  • Keep a food log for a few weeks to estimate selenium intake if you are uncertain about diet quality. Discuss findings with your provider or a registered dietitian.
  • If you have thyroid disease, autoimmune conditions, or are pregnant, discuss selenium status with your clinician because requirements and benefits of supplementation can differ.

When to Talk with Your Healthcare Provider

  • If you have symptoms such as unusual fatigue, hair loss, brittle nails, or new thyroid symptoms.
  • If you are considering taking a selenium supplement or are already taking one and want to check dose safety.
  • If you follow a restrictive diet, have malabsorption issues, or have chronic health conditions that could affect nutrient levels.

PlexusDx provides genetic information to help you understand potential predispositions related to nutrient transport and metabolism. This information is educational and not medical advice. Always consult your healthcare provider before making changes to supplements, medications, or major dietary patterns. Your provider can interpret genetic results in the context of your full medical history, lab tests, and current health concerns.