Vitamin B12 deficiency symptoms can mimic normal aging, researchers report
6 reported
A new report from The Conversation highlights that vitamin B12 deficiency remains common and its symptoms are often mistaken for normal aging. Adults need only about two micrograms of B12 daily, but a shortage can cause fatigue, weakness, numbness, memory problems, and brain fog. The vitamin was first linked to treating pernicious anemia nearly 100 years ago after doctors found that a liver-rich diet could save patients. Today, researchers are investigating how B12 helps mitochondria produce energy, which may explain why some people feel exhausted before anemia is detected. A 2026 study in laboratory models found that low B12 could interfere with mitochondrial DNA and reduce energy production. Another study in aged female mice showed that B12 supplementation improved mitochondrial health in muscle. The report notes that B12 injections are an established treatment for diagnosed deficiency but there is little evidence they boost energy in people with normal B12 levels.
What’s reported
Adults need only about two micrograms of vitamin B12 each day.
Vitamin B12 deficiency is common among older adults, vegans, vegetarians, and people with absorption issues.
Symptoms of deficiency include exhaustion, weakness, shortness of breath, numbness, poor balance, memory problems, and brain fog.
A 2026 study found low B12 could interfere with mitochondrial DNA and reduce energy production in lab models of skeletal muscle.
A related study in aged female mice found B12 supplementation improved mitochondrial health in muscle.
B12 injections are an established treatment for diagnosed deficiency but lack evidence as an energy booster for people with normal B12 levels.
Key figures
Martin Warren, Chief Scientific Officer and Group Leader, Synthetic Biology and Biosynthetic Pathways, Quadram Institute (author of the original article)
George Minot and William Murphy (reported liver-rich diet could treat pernicious anemia in 1926)
George Whipple (showed liver helped dogs recover from anemia caused by blood loss)
Sources: ScienceDaily
