Vitamin B12 deficiency symptoms range from fatigue and tingling to nerve damage. Learn every warning sign, who is at risk, and how it is diagnosed and treated.
Frequently Asked Questions
What are the first signs of vitamin B12 deficiency?
The earliest signs are often fatigue, weakness, and mild tingling or numbness in the hands and feet. These can appear before any change in blood counts, making B12 deficiency easy to miss in early stages.
What does B12 deficiency feel like in your legs?
B12 deficiency typically causes numbness, tingling, or a "pins and needles" sensation in the legs and feet. In advanced cases it leads to weakness, balance problems, and difficulty walking due to spinal cord damage known as subacute combined degeneration.
Can B12 deficiency cause anxiety or depression?
Yes. B12 is essential for synthesizing neurotransmitters like serotonin and dopamine. Deficiency can cause mood changes, irritability, anxiety, and depression — symptoms frequently mistaken for a primary mental health condition rather than a nutritional one.
How long does it take to recover from B12 deficiency?
Blood markers normalize within about one week of treatment. Anemia corrects in 6–8 weeks. Neurological symptoms improve over 3–6 months, though recovery may be incomplete if the deficiency was severe or left untreated for a long time.
Who is most at risk of vitamin B12 deficiency?
The highest-risk groups are adults over 50, vegans and strict vegetarians, people with pernicious anemia, long-term metformin or proton pump inhibitor users, and individuals who have had bariatric surgery.