B12 deficiency feels like extreme tiredness, weakness, and "brain fog," often accompanied by nerve issues like tingling (pins and needles) in hands and feet, balance problems, and mood changes such as depression or irritability, plus physical signs like a sore, red tongue and pale skin, because it impacts red blood cell production and nerve health. Symptoms develop slowly and can worsen, affecting energy, cognition, mood, and nerves, but prompt treatment usually improves them.
Key points about vitamin B12 deficiency anemia
Symptoms include weak muscles, numbness, trouble walking, nausea, weight loss, irritability, fatigue, and increased heart rate. Treatment may include vitamin B12 supplements. It is also important to eat a well-balanced diet.
Vitamin B12 deficiency anaemia is usually treated with injections of vitamin B12, called hydroxocobalamin. At first, you'll have these injections every other day for 2 weeks or until your symptoms have started improving. Your GP or nurse will give the injections.
A low B12 level can cause fatigue, weakness, nerve issues like numbness or tingling, cognitive problems (memory loss, confusion, brain fog), mood changes (depression, irritability), and anemia, leading to pale skin and shortness of breath; if untreated, it can result in severe nerve damage, balance problems, and even dementia.
B12 deficiency can trigger specific food cravings, most notably for meat, fish, or eggs, as the body seeks animal-based sources to replenish the vitamin, especially in those on vegetarian/vegan diets or older adults. While cravings for sugary or salty foods can also signal general B-vitamin issues, the distinct urge for protein-rich animal products is a key indicator, but professional testing is crucial for confirmation.
The worst symptoms of B12 deficiency involve severe neurological damage, including severe memory loss, confusion, dementia, psychosis, hallucinations, balance problems, trouble walking, and irreversible nerve damage (neuropathy), alongside serious mental health issues like severe depression or irritability, with physical signs including extreme fatigue, pale skin, and a sore, smooth tongue. These severe cognitive and neurological issues are the most concerning because they can become permanent if left untreated.
To quickly increase B12, focus on animal products (meat, fish, dairy, eggs) and fortified foods (cereals, plant milks, nutritional yeast), but for a significant deficiency or rapid boost, especially if dietary changes aren't enough, consult a doctor for high-dose supplements or B12 injections, as severe cases require medical intervention for proper absorption and treatment, note NHS and Healthline.
Causes of Vitamin B12 deficiency
In our experience, oral spray supplements can take 3 days to increase serum nutrient levels, with a significant increase seen after 10 days, and a deficiency can be turned into an optimal level within 10 weeks.
The foods highest in Vitamin B12 are animal products, with clams and liver (beef, lamb) being exceptionally rich sources, often providing several hundred percent of the daily value in a single serving, alongside seafood like mussels, sardines, and salmon, dairy, eggs, and fortified cereals and nutritional yeast for vegans.
While B12 is best known for being found in animal foods and fortified products, beverages can be a simple and convenient way to increase your intake.
Dietary insufficiency: Vitamin B12 is stored in excess in the liver; however, patients who have followed a strict vegan diet for approximately 3 years may develop a B12 deficiency from a lack of dietary intake. Toxin exposure: Exposure to nitrous oxide can cause vitamin B12 deficiency and neurologic symptoms.
Cutaneous manifestations associated with vitamin B12 deficiency are skin hyperpigmentation, vitiligo, angular stomatitis, and hair changes. A diagnosis of vitamin B12 deficiency is often overlooked in its early stages because these signs are not specific to vitamin B12 deficiency alone.
The BetterYou B12 At-Home Test Kit makes it easy to check your B12 levels with a simple blood test. Accurate lab analysis provides clear results within 5 working days, helping you take control of your health and make informed supplementation decisions.
The best form of B12 is often considered methylcobalamin, as it's a naturally occurring, active form the body uses immediately, though adenosylcobalamin is also an active form, with a combination often recommended for better results, especially for deficiency or absorption issues, while cyanocobalamin, a cheaper synthetic option, is effective but requires conversion and is less ideal for some. For general supplementation, natural forms like methylcobalamin or adenosylcobalamin are preferred for better retention.
Being older than 75 years: People over 75 are more at risk for developing vitamin B12 deficiency because their bodies are often unable to fully absorb vitamin B12. Having a digestive system disorder: Digestive disorders can make it more difficult for your body to absorb vitamin B12.
Five common symptoms of anemia are fatigue/weakness, pale or yellowish skin, shortness of breath, a fast or irregular heartbeat, and dizziness or headaches, all resulting from a lack of healthy red blood cells to carry oxygen. Other signs can include cold hands/feet, brittle nails, or unusual cravings like ice (pica).
Conditions affecting the stomach
Some stomach conditions or stomach operations can prevent the absorption of enough vitamin B12. For example, a gastrectomy, a surgical procedure where part of your stomach is removed, increases your risk of developing a vitamin B12 deficiency.
Symptoms of vitamin B12 or folate deficiency
Individuals with stomach and small intestine disorders, such as celiac disease and Crohn's disease, may be unable to absorb enough vitamin B12 from food to maintain healthy body stores [2,3,49].
Vitamin B12 deficiency can also cause symptoms that affect your brain and nervous system (neurological symptoms), including: numbness. muscle weakness. psychological problems, which can range from mild depression or anxiety, to confusion and dementia.
Good sources of vitamin B12
If you have vitamin B12–deficiency anemia, you may have the typical symptoms of anemia at first, such as fatigue, paleness, shortness of breath, headaches, or dizziness. If left untreated, you may start to notice brain and nervous system symptoms.