Low B12 can make you feel extremely unwell, causing severe fatigue, cognitive issues like memory loss and confusion, neurological symptoms such as numbness, tingling, and balance problems (potentially leading to difficulty walking), mood changes (depression, irritability), digestive issues, pale/yellow skin, and even heart problems, with the most severe cases potentially causing permanent nerve damage if untreated.
muscle weakness. psychological problems, which can range from mild depression or anxiety, to confusion and dementia. problems with balance and coordination. pins and needles.
Key points about vitamin B12 deficiency anemia
Without enough red blood cells, your tissues and organs don't get enough oxygen. Without enough oxygen, your body can't work as well. Symptoms include weak muscles, numbness, trouble walking, nausea, weight loss, irritability, fatigue, and increased heart rate.
Taking doses of vitamin B-12 might cause: Headache. Nausea. Diarrhea.
Once treatment begins, recovery typically follows this timeline: First Few Days to Weeks: Many people notice an increase in energy and improvement in symptoms like fatigue and weakness within the first week of treatment. 1 to 3 Months: Neurological symptoms, such as tingling or memory issues, often start to improve.
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.
Vitamin B12 deficiency causes
Gastritis: Gastritis is inflammation of the stomach lining, and it's a common cause of vitamin B12 deficiency. It can cause vitamin B12 deficiency due to a lack of hydrochloric acid in your stomach, which you need for B12 absorption.
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.
In fact, some studies have even suggested the opposite. For instance, one study noted that individuals who regularly took vitamin B12 supplements gained between 2.5 to 17 fewer pounds (1.2 to 7.7 kg) over a decade than those who didn't supplement.
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.
For the patients with a very low serum B12 level (<100ng/l) and anaemia, macrocytosis or neurological symptoms, the treatment is simple: load the patient with vitamin B12 parenterally (by IM injection) and continue with maintenance vitamin B12 by IM injection every 3 months indefinitely (see below for more details).
Disturbed or blurred vision can also occur as a result of a Vitamin B12 deficiency.
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.
Cardiovascular quirks – Heart murmurs, erratic blood pressure. Severe Anxiety/Panic Attacks – Overwhelming feelings of dread, often without warning. “The Sighs” – B12 deficiency patients sometimes report having to take a deep intake of breath periodically, often unaware they are doing it.
Individuals experiencing a deficiency often report feeling unusually tired or weak, even after adequate sleep. This symptom arises because a lack of B12 impairs the production of red blood cells, leading to fewer cells to transport oxygen throughout the body.
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.
Milk. One of the best drinks with B12 is milk. One cup of whole milk contains approximately 1.32µg of vitamin B12.
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.
People need vitamin B-12 for the brain to work well. If not treated, vitamin B-12 deficiency can lead to issues with the nerves, brain or spinal cord. These might include lasting tingling in the hands and feet or trouble with balance.
Diet. Some people can develop a vitamin B12 deficiency as a result of not getting enough vitamin B12 from their diet. A diet that includes meat, fish and dairy products usually provides enough vitamin B12, but people who do not regularly eat these foods can become deficient.
If you feel worse after your B12 injection, you're not alone, and it doesn't mean something is wrong with the treatment. In many cases, it's a temporary response as your body starts healing and adjusting to better nutrition. But it's important to listen to your body.
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.