Vitamin B12 may shape metabolism and aging more than previously understood.
By Laura Reiley, Cornell University
The study, published in the Journal of Nutrition,
reveals previously unrecognized ways that B12 supports cellular metabolism. It
also identifies early warning signals in the body that may detect nutritional
strain long before classic deficiency symptoms appear.
Vitamin B12 reshapes metabolic understanding
“This is the first study that shows B12 deficiency affects
skeletal muscle mitochondrial energy production,” said corresponding author
Martha Field, Ph.D. ’07, associate professor in the Division of Nutritional
Sciences and in the College of Human Ecology. “It’s highly relevant because
muscles have high energy demands. More importantly, my co-author, Anna
Thalacker-Mercer from the University of Alabama at Birmingham, wondered if B12
supplementation in aged mice would improve muscle mitochondrial function – and
it did.”
Previous research has largely concentrated on the visible
consequences of B12 deficiency, such as megaloblastic anemia, neuropathy, and
cognitive decline, rather than examining the underlying biological mechanisms.
At Cornell, a research group led by Field, along with first
authors Luisa Castillo, Ph.D. ’25, and Katarina Heyden, B.S. ’18, Ph.D. ’24,
investigated these deeper processes. Their work mapped how B12 interacts with
lipid metabolism, organelle stress pathways, and epigenetic regulation. The
results indicate that B12 plays a central regulatory role across multiple
interconnected biological systems, suggesting that even modest deficiencies
could have widespread effects.
“Another thing we observed in mice is that B12 deficiency
seemed to inhibit growth or maintenance of muscle mass,” Field said. “It seems
that low B12 status is associated with lower muscle mass and maybe muscle
strength.”
Subtle deficiency may carry broad risk
B12 deficiency remains widespread across the globe,
particularly among older adults and in populations with limited access to
animal-based foods, which are primary sources of the vitamin. Estimates suggest
that about one in four older adults in developed countries may have suboptimal
B12 levels, highlighting the need for improved detection and intervention.
The findings also align with a growing body of research
showing that insufficient intake of micronutrients, even without full
deficiency, can contribute to chronic disease.
While severe B12 deficiency is relatively uncommon in many
developed regions, marginal levels are still frequently observed in older
adults, as well as in vegans, vegetarians, and individuals with absorption
disorders. The study indicates that even these lower levels may reduce the
body’s ability to cope with metabolic stress, immune challenges, and the
effects of aging.
Toward precision nutrition strategies
From a clinical perspective, the researchers suggest that
B12-related biomarkers could support more personalized approaches to nutrition.
Rather than relying on uniform supplement recommendations, future guidelines
may be tailored to individual metabolic needs and lifestyles, reflecting a
broader move toward precision nutrition. This approach fits within a larger
effort to integrate nutrition science with systems-level biology.
The current findings are based on cell models and will need
to be validated in human studies, Field said.
“We want to understand the whole causal pathway –
understanding the molecules and mechanisms,” Field said. “This sets the stage
for a future controlled human trial.”
Reference: “Vitamin B12 Supports Skeletal Muscle Oxidative
Phosphorylation Capacity in Male Mice” by Luisa F Castillo, Katarina E Heyden,
Abigail R Williamson, Wenxia Ma, Olga V Malysheva, Nathaniel M Vacanti, Anna E
Thalacker-Mercer and Martha S Field, 20 January 2026, The Journal of
Nutrition.
DOI:
10.1016/j.tjnut.2026.101367
