HSA | FSA CARDS ARE NOW ACCEPTED

Last reviewed: May 12, 2026 Last updated: May 12, 2026

Written by: Jay Hastings , CEO of PlexusDx

Jay Hastings is the CEO of PlexusDx, a precision health company focused on genetic testing, blood biomarker insights, and personalized wellness recommendations. He has more than 20 years of experience across healthcare innovation, genomics, laboratory operations, healthcare investing, and strategic finance. His work has included scaling healthcare startups, leading CLIA lab integrations, and helping expand consumer access to precision health tools.

Medically reviewed by: Jayden Lee, PharmD, EMBA

Jayden Lee, PharmD, EMBA, is the PlexusDx Medical Science Liaison with a PharmD and MBA specializing in pharmacogenomics and clinical product development, with a proven ability to bridge the gap between genomic research and practical patient outcomes. Dr. Lee has more than 10 years of professional experience in clinical pharmacy, academia, and research.

How SLC25A32 and Riboflavin (Vitamin B2) Affect Energy and Exercise

Riboflavin, also called vitamin B2, is an essential nutrient that helps convert carbohydrates, proteins, and fats into usable energy. It supports cell growth, red blood cell production, and the activation and metabolism of other B vitamins. Within cells, a riboflavin-derived molecule called flavin adenine dinucleotide, or FAD, is a critical cofactor for enzymes that produce energy in mitochondria. The SLC25A32 gene encodes a mitochondrial transporter that moves FAD into mitochondria. Variants in SLC25A32 can reduce that transport, which in some people leads to low mitochondrial energy output and symptoms such as unusual fatigue or exercise intolerance.

Why this matters

  • Reduced FAD transport can limit mitochondrial enzyme activity and energy production, particularly during physical activity.
  • Symptoms may include muscle tiredness during exercise, prolonged recovery, and overall low stamina.
  • Importantly, these symptoms often respond to increased riboflavin intake because providing more substrate for FAD synthesis can help compensate for reduced transport.

Practical steps to support riboflavin function

Whether your genetic test shows an increased risk or not, riboflavin is essential for energy metabolism. The following diet, supplement, lifestyle, and monitoring suggestions can help support mitochondrial health and overall energy.

Diet

  • Focus on riboflavin-rich foods: dairy (milk, yogurt, cheese), eggs, lean meats (beef, pork, poultry), fatty fish (salmon, mackerel), fortified cereals and bread, almonds, and leafy green vegetables.
  • Include a variety of protein sources to supply amino acids needed for mitochondrial enzymes.
  • Pair carbohydrates and protein around workouts to improve performance and recovery.
  • Limit excessive alcohol, which can impair B vitamin status and mitochondrial function.

Supplements

  • Riboflavin supplements are available in multiple forms. Typical supplemental doses used for riboflavin-responsive exercise intolerance in reported cases have ranged from about 50 mg to 200 mg daily. Lower doses from a multivitamin (1.3 to 2 mg) are adequate for baseline needs in many people.
  • If you have symptoms such as exercise intolerance or unexplained fatigue, discuss higher-dose riboflavin with your healthcare provider to determine appropriateness and dose.
  • Riboflavin is water-soluble and excess is generally excreted in urine; urine may turn bright yellow with supplementation. Still, consult a clinician before starting high-dose supplements and review interactions with any medications you take.

Lifestyle

  • Gradual, consistent exercise helps boost mitochondrial capacity. If you notice exercise intolerance, pace increases in intensity and duration to avoid setbacks.
  • Prioritize sleep quality; sleep supports mitochondrial repair and energy regulation.
  • Reduce chronic stress through practices you find sustainable, such as walking, mindfulness, or yoga, because chronic stress can worsen fatigue.
  • Stay well hydrated and maintain balanced electrolytes during prolonged or intense activity.

When to check labs or seek evaluation

If you experience persistent or unexplained fatigue, exercise intolerance, muscle weakness, or other concerning symptoms, talk to your healthcare provider. They may consider basic tests and targeted evaluations to rule out common causes and to assess nutritional status.

  • Basic blood tests that are commonly reviewed include a complete blood count and metabolic panel.
  • Your clinician may consider tests of nutritional status or muscle metabolism when indicated. Discuss specific testing with your provider.

Genetic Interpretation: SLC25A32 (rs147014855)

The accordion below summarizes genotype-specific interpretations and practical recommendations for the rs147014855 variant in SLC25A32. Each entry describes what the genotype means for FAD transport and energy, typical symptoms to watch for, and suggested dietary, supplement, and lifestyle considerations. PlexusDx does not provide medical advice. Always consult your healthcare provider before starting supplements or making significant changes to your care.

2 effect alleles (TT) — Higher likelihood of riboflavin-responsive exercise intolerance

Interpretation

  • You carry two copies of the effect allele. This genotype is associated with reduced transport of FAD into mitochondria and a higher likelihood of exercise intolerance that has been reported to respond to riboflavin supplementation.
  • This may lead to unusual fatigue during or after physical activity, reduced exercise capacity, or prolonged recovery.

What to consider

  • Prioritize riboflavin-rich foods: dairy, eggs, lean meats, fish, fortified cereals, almonds, and leafy greens.
  • If dietary intake is insufficient or symptoms occur, discuss riboflavin supplementation with your healthcare provider. Clinical reports often use 50 mg to 200 mg daily for riboflavin-responsive exercise issues, but your provider will recommend an appropriate dose.
  • Maintain regular, gradually progressive exercise and give extra attention to rest, recovery, hydration, and sleep.
  • If symptoms persist despite dietary and lifestyle changes, ask your clinician about evaluation and targeted management. Labs and other assessments may help rule out alternative causes.
1 effect allele (CT) — Possible reduced FAD transport with milder impact

Interpretation

  • You carry one copy of the effect allele. This may modestly reduce mitochondrial FAD transport and could contribute to milder exercise intolerance in some people.
  • Carrying one effect allele does not guarantee symptoms, but it can make riboflavin status more important for optimal energy production.

What to consider

  • Emphasize riboflavin-rich foods as part of a balanced diet to support mitochondrial function.
  • If you notice unusual fatigue or problems with exercise, discuss riboflavin supplementation with your healthcare provider. Lower supplemental doses or dietary adjustments may be sufficient.
  • Use gradual training progressions, adequate sleep, and stress management to support energy metabolism.
0 effect alleles (CC) — Typical riboflavin transport

Interpretation

  • You carry two copies of the non-effect allele. This genotype is associated with normal SLC25A32 function and typical transport of FAD into mitochondria.
  • You are not genetically predisposed to riboflavin-related exercise intolerance, but riboflavin remains essential for energy metabolism and overall health.

What to consider

  • Maintain adequate riboflavin intake through diet: dairy, eggs, lean meats, fish, fortified cereals, almonds, and leafy greens.
  • If you have unexplained fatigue or exercise issues, discuss them with your healthcare provider to evaluate other causes.
  • Support mitochondrial health with balanced nutrition, regular activity, good sleep, and stress reduction.

Final notes and disclaimer

This information is intended to help you understand how a variant in SLC25A32 may relate to riboflavin handling and energy. PlexusDx does not provide medical advice. Genetic information is one piece of a larger health picture. Always consult your healthcare provider before starting supplements, changing your diet, or undertaking new treatments or testing. Your provider can interpret genetic results in the context of your symptoms, medical history, medications, and lab results to create a safe, personalized plan.

If this genetic variant is present in your PlexusDx results, the following tests and reports are commonly used to explore it further:

🧬 Genetic Tests:

🧪 Blood Tests:

📄 Genetic Report:

Frequently Asked Questions About Riboflavin and SLC25A32 rs147014855

What does the SLC25A32 rs147014855 variant affect in your energy metabolism?

The SLC25A32 gene helps transport a riboflavin-derived molecule (FAD) into mitochondria, where it supports key enzymes involved in energy production. Variants that reduce FAD transport can lead to lower mitochondrial energy output, which may show up as unusual fatigue, exercise intolerance, reduced stamina, or prolonged recovery—especially during physical activity.

How can riboflavin (vitamin B2) help if you have SLC25A32-related exercise intolerance?

In cases where reduced FAD transport contributes to exercise intolerance, providing more riboflavin can help compensate by increasing the substrate available for FAD synthesis. Diet is a first step (dairy, eggs, lean meats, fatty fish, fortified cereals/bread, almonds, leafy greens). If symptoms occur, discuss supplementation with your healthcare provider, as reported riboflavin-responsive doses are often in the range of about 50 mg to 200 mg daily, with lower multivitamin amounts (around 1.3 to 2 mg) sometimes sufficient for baseline needs.

What practical steps should you take for fatigue or exercise intolerance based on your SLC25A32 genotype?

Support mitochondrial function with riboflavin-rich foods, gradual and consistent training (pacing intensity to avoid setbacks), good sleep, and stress reduction (e.g., walking, mindfulness, yoga). Stay well hydrated and manage electrolytes during intense or prolonged activity. If fatigue or exercise intolerance is persistent or unexplained, seek evaluation—your clinician may review basic labs such as a complete blood count and metabolic panel, and may consider nutrition or muscle metabolism testing when indicated.

What tests can help me learn more about Riboflavin and SLC25A32 rs147014855?

The Optimal Diet and Weight Loss Genetic Test delivers over 295 genetic insights related to nutrition response, body composition, metabolism, and fitness. The Diet and Nutrition Genetic Report translates your results into personalized, actionable guidance. Your healthcare provider can also recommend targeted blood tests based on your specific pathway results and health history to complement your genetic insights with current biomarker data.

Medical and Editorial Standards

Medical review process: This article was reviewed for medical accuracy, scientific clarity, evidence alignment, and appropriate discussion of genetics, medications, supplements, biomarkers, and health-related claims.

Sources and evidence: PlexusDx educational content is developed using peer-reviewed research, clinical literature, reputable medical references, and, where applicable, public health or regulatory guidance. References are included at the end of the article when scientific, medical, or health-related claims are discussed.

Commercial transparency: PlexusDx offers genetic testing, blood biomarker testing, personalized supplement recommendations, and related precision wellness services. Product mentions are intended to help readers understand available options and should not be interpreted as medical advice.

Important disclaimer: PlexusDx educational content is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about medications, supplements, genetic testing, lab testing, or health-related care.