Feeling constantly tired, foggy-headed, or down in the dumps? While it’s easy to blame a bad night’s sleep or a stressful week, these symptoms might actually point to something deeper—like a vitamin B12 deficiency. This essential nutrient plays a key role in keeping your brain sharp, energy levels high, and nervous system functioning properly. Unfortunately, B12 deficiency is often overlooked or misdiagnosed because its symptoms mimic other health issues.

Common Signs of a Vitamin B12 Deficiency

Vitamin B12 deficiency doesn’t always hit you with clear, obvious signs. Instead, it tends to sneak up with subtle symptoms that can easily be dismissed. Fatigue, forgetfulness, and low mood are common, but B12 deficiency can also lead to more serious physical and neurological issues. Here are the red flags to watch for:

• Tingling or numbness in your hands, feet, or legs

• Trouble walking or maintaining balance

• A swollen, red, or inflamed tongue

• Pale or yellow-tinged skin

• Paranoia, hallucinations, or mental confusion

• Muscle weakness or unexplained anemia

Because B12 is essential for producing red blood cells and maintaining nerve health, these symptoms should never be ignored. If you’re experiencing several of these signs, it may be time to talk to your doctor.

Why Your Body Needs B12

Your body can’t produce B12 on its own. That means you need to get it through your diet or supplements. B12 is critical for DNA production, energy metabolism, and brain health. Without enough of it, your entire system can start to suffer.

Shockingly, studies show that up to 40% of adults in North America may have low B12 levels. Those with Chronic Fatigue Syndrome or Fibromyalgia are even more likely to struggle with B12 absorption.

How to Test for a B12 Deficiency

A standard blood test might not always give you the full picture. Serum B12 tests show how much is circulating in your blood, but they don’t always reveal whether your body is actually using the vitamin effectively. For a clearer diagnosis, ask your doctor about intracellular B12 testing. If that’s not available, tests that measure methylmalonic acid (MMA) or homocysteine levels can also offer important clues about your B12 status.

What Causes Low B12?

There are several reasons why someone might develop a B12 deficiency, even if they eat relatively well.

Pernicious Anemia

This autoimmune condition attacks the stomach lining and stops the production of a protein called intrinsic factor, which is needed to absorb B12. Without intrinsic factor, your body can’t absorb B12 from food—no matter how much you consume.

Leaky Gut Syndrome

A damaged or inflamed gut lining can affect nutrient absorption. Conditions like gluten sensitivity, gut infections, or high sugar intake can trigger leaky gut, limiting your ability to absorb B12 and other essential nutrients.

Poor Gut Microbiome

A healthy gut relies on the right balance of bacteria. If your gut is overrun by harmful bacteria (often thanks to a sugar-heavy diet), your nutrient absorption can suffer. Adding probiotics to your diet can help rebuild a healthier microbiome.

Medications

Heartburn medications like proton pump inhibitors reduce stomach acid, which is crucial for B12 absorption. If you’re relying on these medications long-term, you may be unknowingly putting yourself at risk for deficiency.

Chemotherapy

Cancer treatments often damage the gut lining, making it harder for the body to absorb nutrients, including B12 and folate. In these cases, high-quality supplements may be necessary to prevent deficiencies.

How to Replenish Your B12 Levels

The best way to address a B12 deficiency is by tweaking your diet and adding smart supplements.

Eat More Animal Products

B12 is naturally found in animal-based foods. Load up on wild-caught fish, grass-fed beef, free-range poultry, and nutrient-dense organ meats like liver. These foods are some of the most effective natural sources of B12.

Take Supplements If Needed

If you’re vegan, vegetarian, or have trouble absorbing nutrients through food, B12 supplements like methylcobalamin or cyanocobalamin can help. It’s best to speak with your healthcare provider about the right type and dose for you.

Support Your Gut Health

To help your body absorb nutrients more efficiently, support your gut microbiome with fermented, probiotic-rich foods. Options like yogurt, kefir, kimchi, sauerkraut, and even dark chocolate can give your gut bacteria the boost they need.

Ditch Inflammatory Foods

Cutting back on processed food, sugar, and gluten may help heal your gut and improve your ability to absorb B12 and other vitamins. A cleaner diet leads to a healthier digestive system—and better nutrient absorption overall.

Consider Desiccated Liver Capsules

If eating liver isn’t your thing, no worries—desiccated liver supplements are an excellent alternative. They offer the benefits of organ meats without the taste or texture, making them a great source of B12 in capsule form.

Final Thoughts: Don’t Ignore the Signs

Your body depends on vitamin B12 to function at its best. If you’re feeling constantly tired, foggy, or off balance, it could be more than just a rough patch—it might be your body crying out for help. Recognizing the early signs of a deficiency, adjusting your diet, and using the right supplements can make a huge difference in how you feel each day. By taking control of your B12 levels now, you’re setting yourself up for more energy, better focus, and a healthier life overall. Don’t let a deficiency slow you down—take action today.