How Long to Recover From Vitamin B12 Deficiency

Vitamin B12 deficiencies can impact your health in various ways. Despite maintaining a healthy diet, many adults in the U.S. do not get enough vitamin B12. This guide offers insights on recognizing signs of a deficiency in B12 and provides tips on how to recover from a vitamin B12 deficiency.

What is Vitamin B12?

Vitamin B12, also referred to as cobalamin, belongs to a group of eight B vitamins, each offering crucial benefits to the body. Considered essential nutrients in the human diet, B vitamins, including B12, play a vital role in sustaining energy levels and ensuring the proper functioning of critical bodily systems. Specifically, vitamin B12 is essential for metabolism, producing red blood cells, and DNA synthesis.

The full list of B vitamins are:

  • B1: Thiamine
  • B2: Riboflavin
  • B3: Niacin
  • B5: Pantothenic acid
  • B6: Pyridoxal 5'-phosphate
  • B7: Biotin
  • B9: Folate
  • B12: Cobalamin

While B12 is crucial for numerous bodily functions, humans cannot produce vitamin B12 on their own. It must be obtained through diet, supplementation, or injections. Deficiency in this essential nutrient may occur if your body doesn't absorb the vitamin well, possibly due to issues with intrinsic factor. Intrinsic factor is a protein that binds to B12 and facilitates its absorption in the intestines. Alternatively, deficiency could result from a diet low in B12.

Signs and Symptoms of Vitamin B12 Deficiency

Fatigued woman laying down

If you have low vitamin B12 levels or your body has suboptimal B12 absorption ability, you may experience symptoms of a B12 deficiency. To ascertain whether you are deficient, it's crucial to recognize the symptoms you are experiencing and/or consult a healthcare provider for a blood test to assess your serum levels of B12.

If you do not obtain sufficient B12 through your diet or supplements, you may experience the following symptoms:

  • Low energy levels and mild fatigue during daily activities
  • Weak muscles or numbness
  • Rapid heart rate
  • Paleness or hyperpigmentation
  • Sensory issues

It's crucial to note that the severity of symptoms will depend on the extent of your deficiency and other unique physiological and health markers. If you are uncertain whether B12 is the primary cause of any of the mentioned symptoms, consult your physician to conduct a serum level test for B12. This test can help identify low B12 levels through signs of anemia or other abnormal blood results.

How long does it take to recover from vitamin B12 deficiency?

There is no set time for recovering from low levels of B12. The duration of recovery depends on several factors, including the extent of your deficiency, other health markers, and your body's ability to absorb vitamin B12.


If a healthcare provider identifies low B12 levels, they will offer guidance on the expected duration of symptoms and recommend an appropriate treatment plan tailored to your condition. Frequently, physicians may administer the following:

  • Injection: An intramuscular injection of vitamin B12 provides more immediate relief. This treatment may be particularly effective for patients who face challenges in absorbing B12 through diet and supplement consumption. Continuous injections might be necessary if absorption difficulties remain the primary cause of vitamin B12 deficiency in the patient.
  • High-dosage Oral Treatment: Alternatively or in conjunction, physicians may prescribe a high-dose vitamin B12 oral supplement, containing a dosage higher than what is typically available over-the-counter.

If you are experiencing mild symptoms of B12 deficiency and have not consulted a physician, you may choose to supplement with B12 at typical dosages, such as 1,000mcg. The recovery time will vary based on your deficiency level, duration of deficiency, individual physiological factors, and the quality of the supplement, which can differ in bioavailability. Consistently take the B12 supplement for a few weeks and monitor whether symptoms begin to subside. If you are uncertain about the appropriate dosage, consult a physician. Should you encounter any side effects from B12 supplementation, discontinue use immediately.

Prevention and Maintenance of B12 Levels

To prevent symptoms from occurring or reoccurring after recommended treatments, a healthcare provider may suggest modifying your diet to include foods rich in B12. These recommended dietary sources may encompass adequate intake of animal products, dairy products, and/or fortified cereals. If incorporating sufficient B12 into your diet proves challenging, consistent intake of vitamin B12 supplements may be recommended. The daily amount of vitamin B12 needed varies based on individual factors. Supplement dosages range widely, from less than 5mcg to over 1,000mcg. B12 has low levels of toxicity, lacking an upper tolerable limit. However, as a general guideline, up to 1,000mcg per day of B12 supplementation is considered safe. The body's ability to absorb the full dosage depends on the quality and bioavailability of the supplement.

Key Takeaways

The first step in determining if you are getting enough B12 in your diet is to recognize common symptoms including fatigue, muscle and nerve concerns, or neurological symptoms. If you experience any of these symptoms, it is recommended to consult a doctor for a blood test. If a deficiency is identified, B12 treatments may include injections, high oral dosages, typical dosages, and/or dietary modifications.

Unfortunately, there is no one-size-fits-all timeline for recovering from a vitamin deficiency, but prompt identification is crucial. You may notice the effects of treatment immediately or over a span of days or weeks, depending on the severity of the deficiency.

Ultimately, consuming B12-rich foods and supplementing as necessary is crucial for treating, maintaining, and preventing B12 deficiency.

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