Feeling Constantly Tired? It Might Be More Than Just Stress
Have you ever felt exhausted despite getting enough sleep? Struggling with brain fog, mood swings, or tingling sensations in your hands and feet? If so, your body might be trying to tell you something important—your vitamin B12 levels could be low. This could be easily tested with a vitamin B12 test.
Vitamin B12, also known as cobalamin, is essential for energy production, nerve function, and the formation of red blood cells. Since the body can't produce it on its own, we rely entirely on our diet or supplements to get enough. If left unchecked, a vitamin B12 deficiency can lead to serious health issues, including anemia, nerve damage, and even cognitive decline.
In this guide, we'll cover everything you need to know about vitamin B12, including:
- Why B12 is essential for your body
- Who is at the highest risk of deficiency
- Symptoms to watch for
- How to test for B12 deficiency
- Treatment options and dietary sources
Quick Guide
Disclaimer: This information is based on research and is accurate to the best of our knowledge at the time of publication. Please note that the writer has not personally used or tested these products.
Why is Vitamin B12 So Important?
Vitamin B12 plays a crucial role in multiple bodily functions, including:
- Red Blood Cell Production: B12 is necessary for making healthy red blood cells, which transport oxygen throughout your body. Low B12 levels can lead to anemia, causing fatigue and weakness.
- Nerve Function: It helps maintain the protective coating around nerves. A deficiency can lead to nerve damage, numbness, tingling, and coordination problems.
- Brain Health and Mood Regulation: B12 is involved in neurotransmitter function, which affects memory, concentration, and mental health. Low levels are linked to depression, anxiety, and cognitive decline.
- Energy Metabolism: B12 helps convert food into energy. Deficiency can cause persistent fatigue and weakness.
Who is Most at Risk for Vitamin B12 Deficiency?
Some groups are more likely to have low B12 levels, including:
Vegans and Vegetarians
Since B12 is naturally found only in animal-based foods, those following plant-based diets are at a higher risk. While fortified plant milks and cereals contain some B12, supplementation is often necessary.
Older Adults
As we age, stomach acid production decreases, making it harder to absorb B12 from food. This puts adults over 60 at an increased risk.
People with Digestive Disorders
Conditions like Crohn’s disease, celiac disease, and pernicious anemia interfere with B12 absorption.
Those Who Have Had Gastric Surgery
People who’ve undergone gastric bypass surgery or other procedures that affect digestion may struggle to absorb enough B12 from food.
Pregnant and Breastfeeding Women
B12 is crucial for fetal brain development, so pregnant women need adequate levels. Breastfeeding mothers also need enough B12 to ensure their baby gets a sufficient amount through breast milk.
People Taking Certain Medications
Long-term use of medications like metformin (for diabetes) and proton pump inhibitors (for acid reflux) can interfere with B12 absorption.
Signs and Symptoms of B12 Deficiency
B12 deficiency can be tricky to diagnose since symptoms develop gradually and can be mistaken for other conditions.
General Symptoms
- Extreme fatigue and weakness
- Shortness of breath
- Pale or jaundiced skin
- Dizziness
Neurological Symptoms
- Tingling or numbness in hands and feet
- Difficulty walking or balancing
- Memory loss and brain fog
- Mood changes, including depression and anxiety
Digestive Symptoms
- Loss of appetite
- Unexplained weight loss
- Diarrhea or constipation
Why is a Vitamin B12 Test Important?
Checking your vitamin B12 levels is essential for several reasons:
- Early Detection: Identifying a deficiency early allows for timely treatment, reducing the risk of long-term health issues.
- Symptom Management: Correcting low B12 levels can help alleviate fatigue, weakness, and neurological symptoms.
- Preventing Serious Health Risks: If left untreated, B12 deficiency can cause irreversible nerve damage and other severe complications.
- Personalized Treatment: Test results provide clarity on the best course of action, whether through supplements, dietary adjustments, or B12 injections.
- Supporting Overall Health: Keeping B12 levels within a healthy range is particularly important for women in their 30s and 40s, as hormonal changes and dietary habits can increase deficiency risks.
Detecting and addressing a B12 deficiency early is key to maintaining your long-term well-being.
How to Test for Vitamin B12 Deficiency
The most common way to check for a vitamin B12 deficiency is through a simple blood test that measures the amount of B12 present in your system.
Vitamin B12 reference ranges can vary slightly between laboratories, but generally fall within these limits:
- 160 to 950 picograms per milliliter (pg/mL)
- 118 to 701 picomoles per liter (pmol/L)
Additional Tests for B12 Deficiency
In some cases, healthcare providers may order extra tests to confirm a deficiency or rule out other conditions:
- Complete Blood Count (CBC): Assesses red blood cell health to detect anemia, a common complication of B12 deficiency.
- Methylmalonic Acid (MMA) Test: Elevated MMA levels can indicate low B12 levels in the body.
- Homocysteine Level Test: High homocysteine levels may also suggest a B12 deficiency.
Recommended Tests
Verisana Vitamin B12 Test
- Tests for: Vitamin B12 level
- How it works: Buy a kit from Amazon.com, collect your blood on a small card and mail it to a Verisana lab with a prepaid envelope
- Specimen required: Finger prick blood sample
- Results in: 7 - 10 business days
About the test
The Verisana Vitamin B12 test kit is an at-home test designed to measure the level of vitamin B12 in your blood. Simply order your kit, collect a sample at your convenience, and send it back to the lab. Using advanced techniques like enzyme-linked immunosorbent assays (ELISA), the laboratory analyzes your sample to determine your vitamin B12 level. Your results will be accessible online and sent to you via email. The kit includes everything needed for testing—detailed instructions, sampling supplies, and a prepaid return shipping envelope. There are no extra costs; the price covers the scientific analysis and a comprehensive laboratory report.
| Pros | Cons |
|---|---|
| ✅ Easy-to-use ✅ Can be done at your convenience in the privacy of your own home ✅ CLIA-certified lab | ❌ Needs blood sample to dry for one hour and then shipped within 24 hours ❌ Due to regulatory reasons, this test is currently not available in NY/NJ/RI/MD ❌ Must be at least 18 & over to take the test |
empowerDx Vitamin B12 + Folate Test
- Tests for: Vitamin B12 and folate levels
- How it works: Buy a kit from Amazon.com, collect your blood and mail it to empowerDx lab with a prepaid envelope
- Specimen required: Finger prick blood sample
- Results in: 3 - 6 business days
- Special instruction: Avoid Biotin supplements for 3 days before collection. Fast from food and beverage (excluding water) for at least 8 hours before collection.
About the test
The empowerDx Vitamin B12 & Folate Test Kit is an at-home test designed to measure your vitamin B12 and folate levels, helping identify potential deficiencies that can lead to fatigue, anemia, and neurological issues. This test is particularly useful for individuals at risk, such as vegetarians, older adults, or those with absorption disorders. The kit includes everything needed for a simple finger-prick blood sample, which is then mailed to a CLIA-certified lab using a prepaid shipping envelope. Results are typically available online within a few days, providing clear insights into your nutrient levels and guiding dietary adjustments or supplementation if necessary. This convenient, doctor-approved test allows you to monitor your health from the comfort of your home.
| Pros | Cons |
|---|---|
| ✅ Easy-to-use ✅ Can be done at your convenience in the privacy of your own home ✅ CLIA-certified lab ✅ Endorsed by American Pregnancy Association (APA) | ❌ Need to collect enough finger prick blood sample and then ship within 24 hours of registering the kit ❌ Prepaid envelope is only for the US. International postage is at your own cost ❌ Must be at least 18 & over to take the test ❌ This test requires eight hours of fasting from food or beverage (excluding water) before collection. |
Verisana Vitamin Test
- Tests for: Folate and Vitamin B12 level
- How it works: Buy a kit from Amazon.com, collect your blood on a small card and mail it to a Verisana lab with a prepaid envelope
- Specimen required: Finger prick blood sample
- Results in: 7 - 10 business days
About the test
The Verisana Folate and B12 kit is an at-home test designed to measure the levels of these vital vitamins in your blood. Simply order your kit, collect a sample at your convenience, and send it back to the lab. Using advanced techniques like enzyme-linked immunosorbent assays (ELISA), the laboratory analyzes your sample to determine your folate and vitamin B12 levels. Your results will be accessible online and sent to you via email. The kit includes everything needed for testing—detailed instructions, sampling supplies, and a prepaid return shipping envelope. There are no extra costs; the price covers the scientific analysis and a comprehensive laboratory report.
| Pros | Cons |
|---|---|
| ✅ Easy-to-use ✅ Can be done at your convenience in the privacy of your own home ✅ CLIA-certified lab | ❌ Needs blood sample to dry for one hour and then shipped within 24 hours ❌ Due to regulatory reasons, this test is currently not available in NY/NJ/RI/MD ❌ Must be at least 18 & over to take the test |
How is B12 Deficiency Treated?
If your test confirms a deficiency, treatment depends on the severity:
- Mild Deficiency: B12-rich foods and oral supplements.
- Moderate to Severe Deficiency: High-dose B12 supplements or injections (for people with absorption issues).
Best Dietary Sources of Vitamin B12
If you want to boost your B12 levels naturally, focus on these foods:
Animal-Based Sources
- Liver (one of the richest sources)
- Beef, pork, and lamb
- Poultry (chicken, turkey)
- Fish (salmon, tuna, trout)
- Shellfish (clams, mussels, oysters)
- Eggs
- Dairy (milk, cheese, yogurt)
Plant-Based and Fortified Foods
- Fortified cereals
- Fortified plant-based milk (soy, almond, oat milk)
- Nutritional yeast
- Fortified tofu
Should You Get Tested for B12 Deficiency?
If you fall into a high-risk category or are experiencing symptoms, getting tested for vitamin B12 deficiency is a smart move. Early detection can prevent serious complications, improve your energy levels, and support overall well-being.
The Bottom Line
Vitamin B12 is essential for a healthy body and mind. Deficiency is common, especially among vegetarians, older adults, and those with digestive issues. If you suspect you might be lacking in B12, testing is easy and affordable. Addressing a deficiency with diet changes or supplements can significantly improve your quality of life.
Don't ignore the signs—your body is telling you what it needs. Consider getting a B12 test today and take charge of your health!
Disclaimer: This information is for general knowledge and informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health.
References
- Wang H, Li L, Qin LL, Song Y, Vidal-Alaball J, Liu TH. Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency. Cochrane Database Syst Rev. 2018 Mar 15;3(3):CD004655. doi: 10.1002/14651858.CD004655.pub3. PMID: 29543316; PMCID: PMC6494183.
- Health Quality Ontario. Vitamin B12 and cognitive function: an evidence-based analysis. Ont Health Technol Assess Ser. 2013 Nov 1;13(23):1-45. PMID: 24379897; PMCID: PMC3874776.