Condition Watch: Vitamins

Vitamin B12 Levels Within Normal Range Are Linked to Cognitive Decline in Older Adults

The current minimum vitamin B₁₂ recommendations may be insufficient for older adults, with new research revealing that cognitive impairment was linked to levels within the normal range.^1,2

Image credit: MarekPhotoDesign.com | stock.adobe.com

The current recommended daily amount of vitamin B12 for adults is 2.4 μg, which is often obtained through diet. Although vitamin B12 deficiency is relatively uncommon in the US, older adults and individuals with digestive absorption issues are more susceptible.³ Additionally, B12 deficiency can cause various neurological issues, including peripheral neuropathy, cognitive impairment, and gait disturbances.⁴

In a study led by researchers from the University of California, San Francisco, investigators aimed to determine whether vitamin B12 levels—even those considered within the normal range—could be linked to neurological damage or impaired function in healthy older individuals.¹

Cognitive testing results revealed that individuals with lower levels of active vitamin B12 demonstrated slower processing speeds, causing subtle cognitive decline that was more pronounced in older individuals. Additionally, older individuals displayed significant delays in responding to visual stimuli, indicating slower visual processing and overall reduced brain conductivity.^1,2

Further MRI results revealed that individuals with lower holotranscobalamin, or active B12, had a higher amount of white matter hyperintensities, indicating brain damage. The investigators also observed that higher levels of the inactive form of B12 were linked with an increased total tau protein in the blood, which is a sign of neurodegeneration.^1,2

REFERENCES

1. Beaudry-Richard A, Abdelhak A, Saloner R, et al. Vitamin B12 levels association with functional and structural biomarkers of central nervous system injury in older adults. Ann Neurol. Published online February 10, 2025. doi:10.1002/ana.27200

2. Leigh S. ‘Healthy’ vitamin B12 levels not enough to ward off neuro decline. University of California, San Francisco. February 18, 2025. Accessed April 15, 2025. https://www.ucsf.edu/news/2025/02/429491/healthy-vitamin-b12-levels-not-enough-ward-neuro-decline

3. Vitamin B-12. Mayo Clinic. Updated June 28, 2024. Accessed April 15, 2025. https://www.mayoclinic.org/drugs-supplements-vitamin-b12/art-20363663

4. Vitamin B12-associated neurological diseases. Medscape. Updated February 4, 2025. Accessed April 1, 2025. https://emedicine.medscape.com/article/1152670-overview?form=fpf

Prenatal Vitamin E May Reduce Peanut Allergy Risk in Infants

A form of vitamin E known as α-tocopherol (α-T) could reduce the development of food allergy and anaphylaxis, according to findings published in the Journal of Immunology. The study, conducted on newborn mice, revealed that intake of prenatal vitamins, including α-T, during pregnancy could reduce the incidence of peanut allergies in early life.^1,2

Previous research has shown that vitamin E, specifically the α-T isoform, can influence allergic reactions in respiratory conditions. Studies in both humans and mice indicate that α-T is associated with improved lung function and reduced inflammation. The vitamin’s mechanism of action involves blocking certain cell signaling pathways by interacting with a protein called PKCα. Despite these findings, it is not yet understood whether α-T can prevent the development of food allergies or anaphylaxis.^1,2

To further assess the impact of vitamin E on anaphylaxis, researchers used mice that were bred to mimic real-world conditions. These mice were selected because they were prone to eczema and food allergies, reflecting the link seen in humans, where children with eczema are at higher risk for peanut allergies. Male mice with mutations in their skin barrier genes (FT−/− mice) were mated with wild-type females that received a diet supplemented with α-T or a control diet.^1,2

The results demonstrated that supplementing the maternal diet with α-T during pregnancy and nursing resulted in offspring with lower levels of immunoglobulin E antibodies to food allergens. Furthermore, these pups experienced less severe anaphylaxis when exposed to peanuts.^1,2

REFERENCES

1. Kosins AE, Gao H, Blankenship RL, Emmerson LN, Ochoa JA, Cook-Mills JM. Maternal supplementation with α-tocopherol inhibits the development of offspring food allergy, H1R signaling and ultimately anaphylaxis early in life. J Immunol. 2025;214(2):199-210. doi:10.1093/jimmun/vkae041

2. Taking vitamin E during pregnancy may decrease peanut allergy in children. News release. EurekAlert. February 19, 2025. Accessed April 15, 2025. https://www.eurekalert.org/news-releases/1074143

Ongoing Clinical Trial Compares ω-3 Types for Dementia Risk Reduction

ω-3 fatty acids could improve early dementia symptoms and decrease the risk of Alzheimer disease, offering a cost-effective and well-tolerated treatment option for patients. To evaluate its efficacy, researchers from the University of Cincinnati are conducting a clinical trial comparing 2 types of
ω-3 supplements as candidate interventions for older adults
at risk for dementia.1

Fish oil supplements offer a convenient alternative to consuming fish, but they contain triglyceride-bound DHA (TAG-DHA), which differs from the DHA found in fish.¹ Previous clinical trials have studied the impact of ω-3 supplementation on symptoms of dementia, but the studies were minor.² The current trial from the University of Cincinnati is the first of its kind, including a total of 153 adults aged 62 to 80 years with mild cognitive decline.¹
Participants will be randomly assigned to receive either a standard fish oil supplement with TAG-DHA, new supplements with lysophosphatidylcholine-bound DHA, or a placebo for 24 weeks. Individuals are required to provide blood and cerebrospinal fluid (CSF) samples, along with a cognitive assessment at baseline and at week 25.¹

The study aims to assess how DHA levels in CSF relate to both neurodegeneration and cognitive function. They will measure DHA and neurodegenerative biomarkers in CSF samples and then examine whether changes in DHA levels are associated with improvements in planning, problem-solving, and memory.¹

REFERENCES

1. Tedeschi T. UC trial compares omega-3 supplements for elderly adults at risk for dementia. University of Cincinnati. February 24, 2025. Accessed April 15, 2025. https://www.uc.edu/news/articles/2025/02/uc-trial-compares-omega-3-supplements-for-elderly-adults-at-risk-for-dementia.html

2. Additional treatments for dementia risk. Alzheimer’s Society. Updated December 2023. Accessed April 15, 2025. https://www.alzheimers.org.uk/about-dementia/managing-the-risk-of-dementia/additional-treatments-for-dementia-risk/