You walk into a room and immediately forget why. You read the same sentence five times, and it still doesn’t land. You’re not just tired; you feel foggy, sluggish, and a bit like your brain's on low battery mode. Sound familiar? Before you chalk it up to stress, hormones, or “just one of those weeks”, it might be time to talk about the quiet powerhouse of your nervous system: Vitamin B12.
The Surprising Side of B12 Deficiency
Vitamin B12 is often linked to energy, and yes, it’s crucial for helping your body turn food into fuel. But that’s just one chapter in the story.
Here’s what B12 is also doing behind the scenes:
- Supporting our nervous system (think: clear thinking, fast memory recall)
- Helping your body make red blood cells
- Contributing to a stable mood and sharp mental clarity
- Playing a key role in DNA synthesis and neurological function (1)
When levels dip, which is more common than people think — your body might cope… for a while. But your brain? Not so much.
Brain Fog, Forgetfulness & Mental Slumps
Low B12 levels can sneak up on you. Unlike deficiencies that scream with symptoms, B12 quietly drains your mental sharpness, sometimes for years, before anyone catches on.
You might notice:
- Short-term memory issues (“Wait… what was I just saying?”)
- Trouble focusing on conversations or work
- That foggy, slow-processing feeling
- Low motivation or even low mood
One study, which is published in Annals of Neurology Trusted Source found that those with lower B12 levels had slower processing speed, and higher levels were associated with more biomarkers of neurodegeneration. (2)
Who’s Most at Risk (And It’s Not Just Vegans)
We often hear about vegans being at risk for B12 deficiency, and that’s true, because B12 is mostly found in animal products. That’s, however, only part of the picture.
Here’s who else should be keeping a close eye on their levels:
1. Plant-based eaters - Even with fortified foods, the risk remains, especially long-term.
2. People over 50 - Stomach acid drops with age, and B12 absorption depends on good gut function. (3)
3. Anyone on long-term medications - Antacids, metformin (for type 2 diabetes), and certain antibiotics can reduce absorption. (4)
4. Those with digestive issues - Conditions like IBS, Crohn’s, or coeliac disease can block B12 uptake in the gut.(5)
5. People on the Pill - Yes, studies suggest the oral contraceptive pill may lower B12 levels over time.
6. Busy, stressed, burnt-out humans - Chronic stress increases demand for B vitamins, and if you’re not eating or absorbing enough, your nervous system suffers.
“But I Eat Well” – The Gut Absorption Trap
Even if you're eating the right foods – eggs, fish, meat, dairy – your gut might not be making the most of it. B12 is infamously difficult to absorb, relying on a complicated chain of digestion steps and something called intrinsic factor, produced by your stomach lining. (7)
If any part of that chain breaks (looking at you, stress and gut issues), B12 can slide right through you without ever being absorbed. That’s why symptoms often creep in, even when diets look “healthy on paper”.
But How Much B12 Do You Actually Need?
When you start looking into B12 supplements, it can be confusing. Some products contain 100 micrograms, others 2000 micrograms or more, so what’s going on?
The recommended daily amount for adults (NRV) is 2.4 micrograms per day. That’s all your body needs to function well – if you're absorbing it properly. But here’s the catch: after about 2 micrograms, your absorption rate drops dramatically. Only around 1% of the excess B12 gets absorbed through passive diffusion in the gut. So, if you take a 1000-microgram tablet, you're likely absorbing only about 10 micrograms of it at best, sometimes a lot less, especially if your digestion isn’t optimal.
That’s why some brands dose high, especially those that do not use active ready methylated (methylcobalamin) forms of B12. It’s not because your body needs more; it’s because most of what you swallow is lost in the digestive process.
Why Liposomal B12 Is a Smarter Option
Enter liposomal technology - a game-changer in the supplement world.
Instead of relying on your stomach acid or gut lining to do all the work, liposomal B12 is wrapped in tiny protective bubbles (liposomes) that:
- Protect it through digestion
- Help it absorb directly into cells
- Deliver it quickly and efficiently to where it’s needed
Think of it like first-class delivery. And here’s the real win: our B12 spray delivers 300 micrograms per spray, and because it’s in a liquid form, you can adjust the dose to suit your needs. Whether you need just a top-up or more intensive daily support, you’re in control. Whilst we can’t speak for other brands, the forms they use, and whether it will be digested efficiently. Here is our guidance on dosing for Well. Actually, liposomal B12 spray
1. 300 mcg (1 spray) for those who simply require a daily top of to make sure they are optimising their B12 levels
2. 600 mcg (2 sprays) if you are suffering from any of these symptoms, but have not had a test to determine your B12 levels, or have had a test and shows that you are borderline deficient)
3. 1200 mcg (4 sprays) if you have had test results that show that you have low B12 levels and need to increase these levels to optimal.
Can You Take Too Much B12?
While B12 is water-soluble and generally considered safe, extremely high doses over time can cause issues for some people. These can include acne-like skin breakouts, headaches or nausea and, in rare cases, dizziness. Most of these occur only with very high, long-term doses, but it’s another reason to focus on absorption, not excess.
Real Talk: When Should You Consider B12?
If you’re:
- Running on coffee but still exhausted
- Dealing with brain fog despite good sleep
- Plant-based or flexitarian
- Taking the Pill or certain meds
- Over 50 (or supporting someone who is)
- Trying to recover from burnout
...then it’s worth giving your B12 status a second look.
And if you’re not sure whether you’re running low, you can order affordable at-home or GP-recommended blood tests. It’s a quick way to get answers and could save you months of guessing.
The Bottom Line
B12 isn’t just a bonus nutrient; it’s essential. And when it runs low, your brain, mood, and energy take the hit first. The good news? It’s easy to top up, especially when using a high-absorption liposomal spray like the one we’ve developed at Well.Actually. Because your brain deserves to run on full power, not just cruise control.
References:
- Alruwaili M, Alshammari MA, Alkhouli M, et al. Neurological Implications of Vitamin B12 Deficiency in Diet: A Systematic Review and Meta‑Analysis. Healthcare. 2023;11(7):958https://pmc.ncbi.nlm.nih.gov/articles/PMC10094050/
- Medical News Today. Lower, higher B12 levels may be linked to cognitive issues in older people. Published July 12, 2023. Available from: https://www.medicalnewstoday.com/articles/lower-higher-b12-levels-may-be-linked-to-cognitive-issues-older-people-neurodegeneration
- Guetterman HM, Huey SL, Knight R, Fox AM, Mehta S, Finkelstein JL. Vitamin B‑12 and the Gastrointestinal Microbiome: A Systematic Review. Advances in Nutrition. 2022 Mar;13(2):530–558. E-published February 10, 2023. https://pmc.ncbi.nlm.nih.gov/articles/PMC8970816/
- Liu, K.W. et al. Metformin and vitamin B12 deficiency. Diabetes Research and Clinical Practice, 2006.
- Medical News Today. B12 and Crohn’s disease: what is the connection? Published July 23, 2024. Available from: https://www.medicalnewstoday.com/articles/b12-and-crohns
- Shojania, A.M. Oral contraceptives and vitamin B12 levels. The Lancet, 1982. https://pubmed.ncbi.nlm.nih.gov/7037144/
- National Institutes of Health, Office of Dietary Supplements. Vitamin B12 (Cobalamin) Fact Sheet for Health Professionals. Reviewed December 15, 2022. Available from: https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/
