Healthy Lifestyle

Feeling Tired All The Time? It Might Just Be A B12 Thing

Feeling tired, foggy, or moody? Vitamin B12 might be the missing link your body needs for energy, focus, and overall wellness.

Maria Samy
July 3, 2025

Let’s be honest for a moment: most of us don’t think about vitamins unless we’re popping a multivitamin or Googling symptoms at 2 a.m. But there’s one quiet little nutrient that does a lot of heavy lifting behind the scenes: Vitamin B12.

If you’ve been feeling low on energy, struggling with brain fog, or dealing with weird numbness or tingling, your body might be trying to tell you something. And B12 could be the missing piece.

Let’s break it down in real talk.

Downloadable Resource

You can also download our detailed guide for B12 deficiency to learn more about how it can directly improve your overall health and well-being.

What Exactly Is B12?

Vitamin B12, also known as cobalamin (fancy name, we know), is a water-soluble vitamin, meaning your body doesn’t store much of it and you need to keep topping it up. Your body also can’t make it on its own. You’ve got to get it through food or supplements.

Vitamin B12 is essential for producing red blood cells and keeping your nervous system healthy.

Here’s the catch: B12 mostly comes from animal-based foods. Think:

Meat
Fish
Dairy
Eggs

If you’re vegan or mostly plant-based, don’t worry. B12 is added to some cereals, plant milks, and nutritional yeast. Alternatively, you can simply take a supplement and consider it a day’s work.

Note

How much do you need? About 2.4 micrograms per day (more if you’re pregnant or breastfeeding). Doesn’t sound like much, but your body will definitely notice if you’re not getting it.

Why Your Body Low-Key Loves B12

This vitamin might not have the hype of collagen or magnesium, but it’s kind of a big deal. Here’s what it’s doing behind the scenes:

Keeps you energized by helping your body make healthy red blood cells.
Protects your brain and nerves by keeping that nerve insulation (called myelin) strong.
Supports DNA production, aka helps your cells regenerate and repair.

In short: no B12 = no good.

What Happens When You’re Running Low On B12?

Here’s where it gets real. Low B12 doesn’t just make you tired — it can mess with your mood, memory, and even your skin.

Let’s run through what the research says:

1. You Might Feel Tired Or Weak

Without enough B12, your red blood cells can’t carry oxygen properly, so you feel drained, dizzy, or lightheaded. That’s why B12 deficiency is one of the causes of anemia.

2. Matters Big Time In Pregnancy

B12 is crucial for a baby’s brain and spinal cord development. Low levels during pregnancy can increase the risk of birth defects.

3. Supports Bone Health

Low B12 = lower bone density, especially as you get older. It’s one of those silent things that can sneak up on you.

4. May Help Protect Your Eyes

Some studies suggest that B12 plays a role in reducing the risk of age-related macular degeneration, a condition that can impact your central vision.

5. Affects Your Mood

There’s a link between low B12 and depressive symptoms. That’s because B12 helps make serotonin, your brain’s natural mood booster.

6. Memory & Focus Can Take a Hit

People with even slightly low B12 levels have reported forgetfulness, confusion, or “brain fog.” Especially noticeable in older adults.

7. Impacts How Your Body Uses Energy

B12 doesn’t give you energy like caffeine, but it helps your body turn the food you eat into usable energy. So if you’re constantly exhausted, a deficiency could be part of the picture. Whether you’re hitting the gym with a personal trainer or just trying to stay active, your body needs B12 to keep up.

8. Shows Up on Your Skin, Hair, and Nails

Brittle nails, dull skin, or hair thinning? Yup, all have been linked to low B12 levels in some cases.

Who Should Keep An Eye On B12?

You might be at higher risk of B12 deficiency if:
You’re over 60. (Your body doesn’t absorb it as well with age)
You have digestive issues like Crohn’s or celiac disease.
You’ve had weight loss or gut surgery.
You take meds like metformin or acid reducers. (PPIs)
You’re vegan or vegetarian without a reliable B12 source.

What does a deficiency feel like?

Constant tiredness.
Numbness or tingling. (especially in hands/feet)
Mood dips.
Brain fog or forgetfulness.
Pale skin or an inflamed tongue.

If this sounds like you, getting your B12 levels checked is simple and worth it.

How To Get More B12 In Your Life

Best food sources:

Clams, sardines, tuna, salmon.
Liver and organ meats.
Eggs, cheese, yogurt, milk.
Poultry like chicken and turkey.

Plant-based? Stock up on:

Fortified plant milks. (Check the label!)
Nutritional yeast with added B12.
B12-fortified cereals.

If you’re unsure whether you’re getting enough B12, a quick chat with a nutritionist can help you fine-tune your diet or supplements.

Supplements:

If food’s not cutting it, a good B12 supplement is safe, affordable, and easy to take. You’ll find it in tablets, sublingual drops, sprays, and even gummies.

If your deficiency is severe, your doctor might recommend B12 shots, which are super effective and fast-acting.

Don’t Sleep On B12

Vitamin B12 might not be trending on Instagram, but trust us, it’s essential. If you’ve been feeling off, B12 could be one of the easiest things to check and fix. Pay attention to the signals your body’s giving you. Tired for no reason? Struggling to concentrate? Moody? Tingling hands or feet? Just ask your doctor for a quick B12 test.

Low B12 levels can lead to fatigue, memory problems, mood changes, and even nerve damage if left untreated.

Getting your levels back on track can literally change how you feel, with more energy, better focus, stable mood. It’s a small thing with a big impact.

Downloadable Resource

Download our B12 deficiency guide to expand on the myths and hidden facts that need special attention from everyone.

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Maria Samy

Maria is a therapeutic nutrition specialist and Head of Nutrition at Saudi-German Hospital, San Mark Hospital, and Andalusia Smouha Hospital. With an ESPEN Diploma and expertise in ICU, cardiology, diabetes, sports nutrition, and more, she provides tailored nutrition plans for all age groups, from 6 months to the elderly, ensuring optimal health and wellness.

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