Posted on 02/24/2025 6:19:34 AM PST by Red Badger
Your brain might not be getting enough B12 — even if your levels are considered “normal.”
A new study suggests that older adults with lower B12, even within the accepted range, show signs of cognitive decline and brain damage. Researchers found that these individuals had slower thinking and reaction times, along with white matter lesions linked to dementia.
Normal B12 Levels Still Linked to Brain Deficiency
Getting the recommended amount of vitamin B12 is essential for making DNA, red blood cells, and nerve tissue. But new research suggests that meeting the minimum requirement may not be enough — especially for older adults. In fact, having lower B12 levels, even within the normal range, could increase the risk of cognitive impairment.
A study led by researchers at the University of California, San Francisco found that healthy older adults with lower B12 levels showed signs of neurological and cognitive decline. These individuals had more damage to the brain’s white matter — the nerve fibers that enable different parts of the brain to communicate — and performed worse on tests measuring cognitive and visual processing speeds compared to those with higher B12 levels.
The study was published in Annals of Neurology on February 10.
Rethinking B12 Guidelines for Brain Health
Senior study author Dr. Ari J. Green, from UCSF’s Departments of Neurology and Ophthalmology and the Weill Institute for Neurosciences, says the findings raise concerns about current B12 recommendations.
“Previous studies that defined healthy amounts of B12 may have missed subtle functional manifestations of high or low levels that can affect people without causing overt symptoms,” said Green, noting that clear deficiencies of the vitamin are commonly associated with a type of anemia. “Revisiting the definition of B12 deficiency to incorporate functional biomarkers could lead to earlier intervention and prevention of cognitive decline.”
Lower B12 Correlates with Slower Processing Speeds, Brain Lesions
In the study, researchers enrolled 231 healthy participants without dementia or mild cognitive impairment, whose average age was 71. They were recruited through the Brain Aging Network for Cognitive Health (BrANCH) study at UCSF.
Their blood B12 amounts averaged 414.8 pmol/L, well above the U.S. minimum of 148 pmol/L. Adjusted for factors like age, sex, education, and cardiovascular risks, researchers looked at the biologically active component of B12, which provides a more accurate measure of the amount of the vitamin that the body can utilize. In cognitive testing, participants with lower active B12 were found to have slower processing speed, relating to subtle cognitive decline. Its impact was amplified by older age. They also showed significant delays responding to visual stimuli, indicating slower visual processing speeds and generally slower brain conductivity.
Cognitive Decline Could Affect More People Than Expected
MRIs revealed a higher volume of lesions in the participants’ white matter, which may be associated with cognitive decline, dementia or stroke.
While the study volunteers were older adults, who may have a specific vulnerability to lower levels of B12, co-first author Alexandra Beaudry-Richard, MSc, said that these lower levels could “impact cognition to a greater extent than what we previously thought, and may affect a much larger proportion of the population than we realize.” Beaudry-Richard is currently completing her doctorate in research and medicine at the UCSF Department of Neurology and the Department of Microbiology and Immunology at the University of Ottawa.
Rethinking B12 Deficiency and Supplementation
“In addition to redefining B12 deficiency, clinicians should consider supplementation in older patients with neurological symptoms even if their levels are within normal limits,” she said. “Ultimately, we need to invest in more research about the underlying biology of B12 insufficiency, since it may be a preventable cause of cognitive decline.”
Reference:
“Vitamin B12 Levels Association with Functional and Structural Biomarkers of Central Nervous System Injury in Older Adults”
by Alexandra Beaudry-Richard, Ahmed Abdelhak, Rowan Saloner, Simone Sacco, Shivany C. Montes, Frederike C. Oertel, Christian Cordano, Nour Jabassini, Kirtana Ananth, Apraham Gomez, Azeen Keihani, Makenna Chapman, Sree Javvadi, Shikha Saha, Adam Staffaroni, Christopher Songster, Martin Warren, John W. Boscardin, Joel Kramer, Bruce Miller, Joshua W. Miller, Ralph Green and Ari J. Green, 10 February 2025,Annals of Neurology.
DOI: 10.1002/ana.27200
Authors: Co-first author is Ahmed Abdelhak, MD, PhD, of the UCSF Department of Neurology and the Weill Institute for Neurosciences. For a full list of authors, please see the study.
Funding and Disclosures: Westridge Foundation and the Canadian Institutes of Health and Research. There are no conflicts of interest to report.
I'm guessing you're talking about supplements and not foods with B12?
If it isn’t absorbed then why does it change your urine color?
In oral form vitamin B12 is absorbed by the body through the digestive tract. Because many blood vessels are found there, vitamin B12 is readily absorbed.
Studies have found that vitamin B12 taken orally is just as beneficial as intravenous.
Enterochromaffin-like cells or ECL cells are a type of neuroendocrine cell found in the gastric glands of the gastric mucosa beneath the epithelium, in particular in the vicinity of parietal cells, that aid in the production of gastric acid via the release of histamine.
Roughly 95% of total body serotonin is released into the gut by intestinal ECL cells.
Histamines also cause allergic reactions. That’s why we take anti-histamines to dry up our sinuses.
Now you made me look!
One A Day Men’s 50+
B12 / 25 mcg / 1042%
Not true in the elderly.
Please read my post 18 to understand the B-12 absorption process.
Researchers account for education when testing Vitamin B-12’s effects on brain health because education level is a known factor that influences cognitive performance and brain resilience—often called “cognitive reserve.” It’s not that education directly changes B-12 levels, but it can mask or amplify how B-12 deficiency (or sufficiency) shows up in brain function tests, making it a critical variable to control for.So, good catch on the seemingly odd "education" correction, but that Grok explanation makes a lot of sense.People with higher education tend to have better baseline cognitive skills—like memory, problem-solving, or processing speed—thanks to years of mental training. This cognitive reserve can delay or hide the observable effects of brain aging or nutrient-related decline, even if B-12 levels are low. For example, someone with a college degree might ace a memory test despite mild B-12 deficiency because they’ve built up neural workarounds, while someone with less education might flunk the same test with identical B-12 levels due to less cognitive buffering. Without adjusting for education, you’d risk misinterpreting results—either overestimating B-12’s protective effect in educated folks or underestimating it in others. In studies like the one from The American Journal of Clinical Nutrition, researchers use MRI scans for brain volume and sometimes cognitive tests. Education correlates with brain volume too—more educated people often show less atrophy over time, possibly from denser neural networks or lifestyle factors tied to schooling (e.g., better diets or healthcare access). If you don’t account for this, you might attribute less brain shrinkage to B-12 when it’s partly just education at work.
They’d adjust for it statistically—say, through regression models—where education is a covariate alongside age, sex, or other confounders. This isolates B-12’s specific impact on brain health, stripping out education’s noise. It’s about getting a cleaner signal: is B-12 really slowing brain aging, or are we just seeing the perks of a diploma?
“If it isn’t absorbed then why does it change your urine color?”
B Vitamins are water soluble. The excess is discharged in urine.
“I think I need more zinc. My vitamin says it’s only 35% of RDV...”
I take 50 mg of Zinc everyday. If you find a Zinc supplement with Calcium and/or Potassium even better.
I started taking B12 as a daily supplement a couple months ago and its made a huge difference from an energy perspective.
Cause it is going straight thru your system?
I get B12 injections from a Homeopathic doctor every couple weeks, I have for several years and I can tell the difference in my energy levels though my b12 is “normal” on lab tests.
Prefer the liquid form myself. 1/2 teaspoon daily of super B-12 does a body good.
Depends if you have absorption issues.
These come with age. Also alcohol use, even moderate.
Absorption also requires a fair amount of stomach acid, so if you take anti-acids, absorption can be low. Some advice NOT to take B12 with foods like milk for the same reason.
Vegans would be Deeply Saddened if they weren’t already in Memory Care:
“What are some food sources high in vitamin b12?
ChatGPT said:
Vitamin B12 is essential for nerve function and the production of red blood cells. Here are some food sources that are particularly high in B12:
Animal Liver and Kidneys (especially beef liver) – These organ meats are some of the richest sources of vitamin B12.
Fish – Fish like salmon, trout, sardines, and tuna are excellent sources of B12.
Shellfish – Clams, oysters, and mussels are very high in vitamin B12.
Meat – Poultry, beef, and pork are good sources of B12.
Dairy Products – Milk, cheese, and yogurt are all rich in B12.
Eggs – Especially the yolks, are a good source of vitamin B12.”
The chemical interactions in the body are somewhat complex.
Note that the parietal cells produce acid which is required for Iron absorption. Iron is what facilitates the red blood cells to carry oxygen. Hypoxia or O2 deficiency has many symptoms such as anemia.
This is why B-12 deficiency is also associated with Pernicious Anemia, a disease where not enough red blood cells are produced due to a deficiency of vitamin B-12. The most common initial symptoms are feeling tired and weak.
Other symptoms of Pernicious Anemia may include shortness of breath, feeling faint, a smooth red tongue, pale skin, chest pain, nausea and vomiting, loss of appetite, heartburn, numbness in the hands and feet, difficulty walking, memory loss, muscle weakness, poor reflexes, blurred vision, clumsiness, depression, and confusion. Without treatment, some of these problems may become permanent.
Pernicious anemia refers to a type of vitamin B12 deficiency anemia that results from lack of intrinsic factor.
IOW:
ANIMAL PROTEINS!....................
Me too.
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