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Doctor's Assessment Included

Every result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.

Vitamins

Vitamin B12 Blood Test: Are Your Levels Optimal?

Vitamin B12 is considered important for oxygen transport via red blood cells and energy metabolism during exercise. Active individuals may have increased requirements. Healthcare providers specialising in sports medicine can help assess your optimal levels.

Reference Ranges

Male
pmol/l
Low 145 Normal 569 High
Female
pmol/l
Low 145 Normal 569 High

Reference ranges may vary between laboratories. When you order a test, a BIG-registered doctor assesses your personal results in context. For treatment decisions, discuss your results with your GP.

What It Measures

This test measures the total vitamin B12 level in your blood, expressed in pmol/l. It may help assess whether your body has adequate B12 for blood cell production and nervous system maintenance. Your healthcare provider can place results in clinical context.

Why It Matters

For active individuals, B12 may support oxygen delivery to muscles, energy production, and recovery. Suboptimal levels have been associated with decreased endurance and prolonged fatigue after training. Consult a sports medicine professional for tailored recommendations.

When to Test

Testing may be recommended when experiencing persistent fatigue, numbness or tingling, difficulty concentrating, or mood changes. Healthcare providers may also suggest testing for vegetarians, vegans, older adults, or those with gastrointestinal conditions affecting absorption.

Symptoms

Low Levels

Some people with low vitamin B12 may experience fatigue, weakness, pale skin, numbness or tingling in extremities, and difficulty with balance. Mood changes and memory difficulties have also been reported. A healthcare provider can help identify the underlying cause.

High Levels

Elevated vitamin B12 levels may sometimes occur with supplementation or certain medical conditions. While generally considered less concerning than low levels, persistently high B12 may warrant investigation. Your healthcare provider can advise on appropriate follow-up.

Recommendations

Male

If Low

Low B12 may cause fatigue, neurological symptoms, and anemia. Consider B12 supplementation (1000 mcg daily) or injections if severely deficient.

If High

High B12 is generally not concerning and may indicate recent supplementation. No action needed unless symptomatic.

Female

If Low

Low B12 may cause fatigue, neurological symptoms, and anemia. Consider B12 supplementation (1000 mcg daily) or injections if severely deficient.

If High

High B12 is generally not concerning and may indicate recent supplementation. No action needed unless symptomatic.

Lifestyle Tips

Foods considered rich in B12 include meat, fish, eggs, and dairy products. Those following plant-based diets may benefit from fortified foods or supplements. Absorption may decrease with age, so regular monitoring could be helpful. Discuss options with your healthcare provider.

Frequently Asked Questions

Who is most at risk for vitamin B12 deficiency?
People following vegetarian or vegan diets, older adults, and those with gastrointestinal conditions such as Crohn's disease or celiac disease may be at higher risk. Healthcare providers can help determine your individual risk and recommend appropriate monitoring.
Can vitamin B12 deficiency cause permanent damage?
Prolonged B12 deficiency may potentially lead to irreversible neurological damage in some cases. Early detection and treatment are generally considered important. If you suspect a deficiency, consult your healthcare provider promptly for evaluation and guidance.
How is vitamin B12 deficiency typically treated?
Treatment may include oral supplements, dietary changes, or in some cases injections, depending on the cause and severity. Your healthcare provider can recommend the most appropriate approach based on your individual circumstances and test results.

Test Products

This marker is included in the following test panels.

Health Checkups

InsideTracker

A 36-biomarker performance and longevity panel inspired by InsideTracker Ultimate — covering heart, hormones, metabolism, inflammation, recovery and iron status.

SHBG (Sex Hormone Binding Globulin) TSH (Thyroid Stimulating Hormone) ALT (Alanine Aminotransferase) LDL Cholesterol GGT (Gamma-Glutamyl Transferase) Cortisol DHEA-S Estradiol (E2) Free Testosterone Total Testosterone Folate (Folic Acid) Vitamin B12 Calcium Ferritin Iron (Serum) Magnesium Magnesium (Intracellular) Potassium Progesterone Sodium Transferrin CRP (C-Reactive Protein) Glucose (Fasting) HbA1c (Glycated Hemoglobin) ApoB (Apolipoprotein B) HDL Cholesterol Total Cholesterol Albumin AST (Aspartate Aminotransferase) Vitamin D (25-OH) Insulin (Fasting) Leukocyte Differential Creatine Kinase (CK) Transferrin Saturation Triglycerides Complete Blood Count (CBC)
€399,-
Complete Health

360 Health

Broad health panel: hormones, thyroid, vitamins, lipids, liver, kidney, and blood count.

HbA1c (Glycated Hemoglobin) TSH (Thyroid Stimulating Hormone) Triglycerides Urea (BUN) Creatinine eGFR (Estimated Glomerular Filtration Rate) Free T4 (Thyroxine) LDL Cholesterol Liver Function Test (LFT) SHBG (Sex Hormone Binding Globulin) Vitamin B12 Vitamin D (25-OH) Free Testosterone Total Testosterone Free T3 (Triiodothyronine) Ferritin HDL Cholesterol Albumin Complete Blood Count (CBC)
€346,-