Vitamin B12

Vitamin B12, also known as cobalamin, is an essential water-soluble vitamin that plays a crucial role in maintaining nerve health, supporting red blood cell formation, and aiding DNA synthesis. It is particularly important for brain function and energy production, as it helps in the conversion of food into usable energy.

When to consult a doctor for vitamin B12 deficiency?

If you experience persistent fatigue, tingling, or memory problems

See a doctor if you feel constantly tired, notice pins-and-needles sensations in your hands or feet, or experience memory and concentration issues, as these can be early signs of B12 deficiency affecting nerves and brain function.

If you have pale or yellowish skin, dizziness, or digestive issues

Consult a GP if you notice changes in skin tone, feel lightheaded or dizzy, or have digestive problems such as those caused by Crohn’s disease, celiac disease, or past gastric surgery, which may impair B12 absorption.

If you are at higher risk due to diet or medical conditions

Seek medical advice if you follow a vegetarian or vegan diet, or have conditions that reduce B12 absorption, to ensure timely testing and treatment before complications develop.

This guide does not replace professional care. Consult a doctor to manage your symptoms. In emergencies, call 000. The content is research-backed & medically reviewed by Dr. Ammar AL-ANI, MBChB, CCBST, AMC

Causes

Vitamin B12 deficiency occurs when the body does not get enough B12 from the diet or cannot absorb it properly. Since B12 is essential for red blood cell formation, nerve function, and DNA production, its deficiency can lead to serious health issues.

1. Inadequate dietary intake

People who do not consume enough B12-rich foods are at a higher risk of deficiency. This includes:

Vegans and vegetarians: B12 is primarily found in animal products like meat, eggs, and dairy.

Older adults: May have reduced appetite or dietary restrictions leading to insufficient B12 intake.

2. Malabsorption issues

Even if a person consumes enough B12, their body may not absorb it properly due to:

Pernicious anaemia: An autoimmune condition where the stomach does not produce enough intrinsic factor (a protein needed for B12 absorption).

Gastrointestinal disorders: Conditions like Crohn’s disease, celiac disease, and atrophic gastritis can reduce absorption.

Weight loss surgery: Procedures like gastric bypass remove parts of the stomach and intestines, limiting B12 absorption.

3. Low stomach acid production

Stomach acid is essential for breaking down B12 from food. Older adults and individuals taking acid-reducing medications (such as PPIs or H2 blockers) are at a higher risk.

H. pylori infection: This bacteria, linked to stomach ulcers, can affect B12 absorption.

4. Alcoholism:Excessive alcohol consumption can damage the stomach lining and interfere with nutrient absorption, including B12.

5. Pregnancy and breastfeeding:Pregnant and breastfeeding women need higher B12 levels to support fetal and infant development. If they have low B12 intake, both the mother and baby may be at risk of deficiency.

What does vitamin B12 test diagnose?

Identifies B12 deficiency, which can cause fatigue, nerve issues, and cognitive problems.

Helps diagnose pernicious anaemia, a condition where the body can’t absorb B12 properly.

Assesses B12 levels in people at higher risk, such as vegetarians, vegans, or those with digestive disorders.

Monitors B12 levels in individuals receiving B12 injections or supplements.

If you are experiencing symptoms, speak to a GP first to discuss your health.

Hola Health provides a convenient way for you to consult a doctor online, 24/7 across Australia. Our AHPRA-registered Australian online GP will conduct a comprehensive assessment to provide the best possible care.

Clinical note: An online GP assessment helps provide medical advice for your symptoms and evaluate if a face-to-face consultation or physical examination is needed. Online GPs can provide prescriptions, pathology referrals, or GP medical certificates if clinically indicated. Telehealth is a complementary service; while a GP can provide clinical advice and pathology referrals, a physical examination or in-person blood test is required to confirm a diagnosis. Bulk billing is available for eligible patients during Medicare-defined after-hours periods; otherwise, private fees apply. Consultations are secure, encrypted, and Australian-stored (in compliance with the Australian Privacy Principles). In case of sudden severe weakness, confusion, or medical emergencies, call 000 immediately. We recommend sharing your consult summaries with your regular GP to ensure continuity of care.