How low does B12 have to be for injections?

Vitamin B12 injections are typically used when levels are below 200 pg/mL (148 pmol/L), especially with symptoms like fatigue or neurological issues, or if levels are borderline (200-300 pg/mL) but other tests (like MMA/homocysteine) show deficiency or symptoms persist despite oral intake. The decision hinges on low numbers, clinical signs, and the cause, with irreversible issues often requiring lifelong injections, while dietary causes might switch to high-dose oral supplements after initial injections.

What are the criteria for B12 injections?

If you have had neurological symptoms that affect your nervous system, such as numbness or tingling in your hands and feet, caused by a vitamin B12 deficiency, you'll be referred to a haematologist and may need to have injections every 2 months.

What level of B12 is dangerously low?

A dangerously low B12 level is generally considered below 200 pg/mL, often leading to symptoms like fatigue, nerve issues (numbness, tingling), anemia, and cognitive problems, with levels under 100 pg/mL in older adults signaling a more severe deficiency, though even borderline levels (200-300 pg/mL) warrant further testing, especially with symptoms, using markers like methylmalonic acid (MMA) for accuracy.
 

How do you treat B12 deficiency in pregnancy?

Intramuscular hydroxocobalamin and oral cyanocobalamin are treatment options for the management of clinically relevant vitamin B12 deficiency during pregnancy.

What are the facial signs of 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.

Vitamin B12 Injections - Everything you need to know with Dr Mandy

What medications affect the absorption of vitamin B12?

Common medicines affecting vitamin B12 absorption include Proton Pump Inhibitors (PPIs), H2-receptor antagonists (H2RAs), and the diabetes drug Metformin, all reducing stomach acid or altering gut function needed for B12 release and absorption, plus antiseizure drugs like phenytoin, anti-gout meds like colchicine, and some antibiotics. Chronic use can lead to deficiency, causing fatigue, nerve issues, or anemia, requiring monitoring by a doctor, says The Economic Times and the NHS. 

How do you feel when B12 is low?

When B12 is low, you often feel extremely tired and weak, experience numbness/tingling (pins and needles) in hands/feet, have pale skin, and suffer from "brain fog," memory issues, or mood changes like depression, alongside a sore tongue, balance problems, and shortness of breath, because B12 is crucial for nerve health and red blood cell production. 

How long does a B12 injection last?

A B12 injection's effects typically last from a few days to several weeks, depending on your deficiency level, metabolism, and the type of B12 used (like hydroxocobalamin lasts longer than cyanocobalamin), with initial doses often needing weekly shots before spacing out to monthly or longer maintenance, especially for conditions like pernicious anemia where lifelong treatment is needed. 

Is a B12 injection better than oral supplements?

If you're dealing with a severe deficiency, low energy, or digestive issues, Vitamin B12 Injections are likely the better choice due to their high absorption rate and fast-acting benefits. Oral supplements may be sufficient if you're maintaining good health and prefer a daily routine.

What do you crave when your B12 is low?

B12 deficiency can cause specific food cravings, particularly for meat, fish, or eggs, as your body seeks sources of the vitamin, and may also lead to sugar cravings due to its role in serotonin and energy regulation, but it can also manifest as pica (craving non-food items like ice or even bleach in severe cases). These cravings signal your body trying to correct a nutrient imbalance, but clinical testing is needed for a proper diagnosis, as emotional factors also drive cravings. 

What is a Stage 4 B12 deficiency?

Stage 4 B12 deficiency is the severe, clinical stage, marked by significant neurological issues like nerve damage (spinal cord degeneration, numbness, paralysis risk), cognitive decline (memory loss, confusion), and severe anemia (megaloblastic anaemia), leading to fatigue, depression, and balance problems, requiring urgent treatment with B12 injections to prevent permanent damage, as symptoms overlap with other neurological conditions.
 

Why do I need B12 injections?

You need B12 injections primarily to treat or prevent a deficiency, especially if your body can't absorb it from food/pills due to digestive issues (like pernicious anemia, Crohn's, celiac) or if you're a strict vegan/vegetarian, delivering the vitamin directly into the bloodstream for energy, mood, nerve function, and to avoid complications like anemia, neurological problems, and memory issues.
 

What are the two main causes of B12 deficiency?

Lack of vitamin B12 in your diet: People who don't eat enough foods that have vitamin B12 or don't eat foods fortified with B12 can develop a deficiency. Gastritis: Gastritis is inflammation of the stomach lining, and it's a common cause of vitamin B12 deficiency.

What are signs you need a B12 shot?

You know you might need B12 injections if you have symptoms like extreme fatigue, tingling/numbness (pins and needles) in hands/feet, a sore red tongue, memory issues, depression, balance problems, or pale skin, often accompanied by a confirmed B12 deficiency via blood test, especially if you have absorption issues from conditions like Crohn's/celiac, follow a vegan diet, or are an older adult. A doctor diagnoses this through symptoms and blood tests, as many signs overlap with other conditions. 

Why are doctors stopping B12 injections?

Coronavirus has made it necessary to move patients on B12 injections to oral treatment. Reason: RISK REDUCTION in terms of limiting your movement outside your home and contact with our staff and nurses. Nationally all NHS organisations will be stopping injections during this difficult time.

How much does a B12 shot typically cost?

B12 injection prices vary widely, from as low as $15-$25 per shot at some clinics or with discount cards for the medication itself, up to $80 or more for a single visit that includes professional administration, provider fees, or bundled packages, with costs often dropping to $20-$50 per shot when bought in bulk or part of a wellness program. Factors like location (urban areas cost more), provider (doctor vs. spa), dosage, and whether it's a single shot or part of a package (like MIC injections) significantly influence the final price.
 

How soon will I feel better after a B12 injection?

Hydroxocobalamin starts to work straight away. However, it may take a few days or weeks before your vitamin B12 levels and symptoms (such as extreme tiredness or lack of energy) start to improve. Are there any long-term side effects? It's OK to have hydroxocobalamin injections for a long time.

What are the neurological symptoms of B12 deficiency?

Vitamin B12 deficiency causes a wide range of neurological issues, including tingling/numbness (pins and needles), balance/coordination problems (ataxia), memory loss, confusion, depression, vision disturbances, and muscle weakness, often due to damage to the spinal cord (subacute combined degeneration) and peripheral nerves, which can become permanent if untreated. 

What is the fastest way to fix B12 deficiency?

The fastest way to recover from B12 deficiency, especially severe cases, is through B12 injections (cobalamin), often starting with frequent shots (e.g., every other day for a couple of weeks) to rapidly replenish stores, particularly if neurological symptoms are present, followed by oral supplements or less frequent injections, depending on the underlying cause. While dietary changes and high-dose oral supplements help, injections bypass absorption issues for quicker correction. 

Why do I feel worse after my B12 injection?

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.

What cancels out B12?

There is general consensus that gastric acid–lowering drugs, including proton pump inhibitors (PPIs) and H2-receptor antagonists (H2RAs), and the antidiabetes drug metformin can reduce circulating vitamin B-12 concentrations with prolonged use.

What food is highest in B12?

The foods highest in Vitamin B12 are organ meats (like liver and kidney) and shellfish (especially clams), offering thousands of percent of the daily value in small servings, with fortified cereals, dairy, fish (salmon, tuna, sardines), and eggs also being excellent sources. For vegans, fortified foods like nutritional yeast and plant milks are key, as B12 is naturally found in animal products.
 

What cannot be mixed with B12?

When taking B12, you should avoid taking it with high doses of Vitamin C simultaneously (take them a few hours apart), limit alcohol, and be cautious with certain medications like metformin, proton pump inhibitors (PPIs), H2 blockers, and some anti-seizure drugs, as these can hinder B12 absorption. Also, avoid combining B12, folate, and B6 after a stent placement due to increased risk of blood vessel narrowing, and consult a doctor about other potential interactions like with chloramphenicol.