How long to recover from vitamin B12 deficiency?

In this short article, we will answer the question “How long to recover from vitamin B12 deficiency?”, and discuss the major causes, signs and treatment of a vitamin B12 deficiency.

How long to recover from vitamin B12 deficiency?

The recovery duration varies from person to person, taking into account their condition and the route of administration of vitamin B12 replacement. But we can get an idea of ​​the average treatment time.

Asymptomatic adults:

In asymptomatic adults, the deficiency is usually corrected within 6 to 8 weeks of treatment. Thereafter, for cases with an indication of lifetime replacement, once a month or once every two months.

Symptomatic adults: 

Treatment usually lasts for 2 weeks, followed by vitamin B12 replacement once a month or once every two months.


Treatment for children may take a few months, as replacement is usually given intramuscularly, once a week until the deficiency is corrected.

There are also cases with indications of replacement that last for life. See some of these situations:

  • Pernicious anaemia. Therapy must be continued indefinitely.
  • Vitamin B12 deficient diets: Individuals with vitamin B12 deficient diets (vegans, vegetarians, infants exclusively breastfed by B12 deficient mothers) have normal absorption orally and can be treated this way.

What major signs of a vitamin B12 deficiency are there?

The following symptoms of vitamin B12 deficiency may be observed in the neurological and cardiovascular systems:

  • regular weakness and weariness; pernicious anaemia
  • breathing difficulties;
  • palpitations; difficulty seeing;
  • tingling and loss of feeling in the hands and feet;
  • absence of balance
  • mental uncertainty and memory loss;
  • dementia possibility, which may be irreparable;
  • a lack of appetite and unexpected weight reduction;
  • frequent mouth and tongue sores
  • Irritability;
  • persistently depressing emotions
  • A lack of this vitamin in children can also affect their ability to grow, delay their general development, and result in megaloblastic anaemia, for example.

What may result in a B12 deficiency?

The main causes of vitamin B12 are as follows:

At the stomach level: 

Pernicious anaemia can result in a decrease in intrinsic factor, a substance required for the vitamin’s absorption there. Atrophic gastritis and the use of some medications that block or neutralise stomach acid can interfere with the concentration of this vitamin. 

In addition, gastric acid enhances the separation of vitamin B12 from foods that contain it.

Abdominal level: 

]People who have had the ileum removed or who have Crohn’s disease in which the ileum is compromised do not effectively absorb vitamin B12. The development of bacteria and parasites in the digestive tract are other reasons for B12 insufficiency;


A diet deficient in foods like meat, fish, eggs, cheese, and milk will cause a vitamin B12 deficit because they are the only naturally occurring sources of this vitamin. The elderly, alcoholics, improper eaters, and severe vegetarians are the groups most in danger.


Additionally, the absorption of B12 in the intestine can be decreased by the use of medications.

Some examples are antibiotics, Metformin, and treatments for gastritis and gastric ulcers, such as Omeprazole, thus it is advised to speak with the doctor to see whether vitamin supplements are necessary.

How is the therapy carried out?

The reason for vitamin B12 insufficiency affects how it is treated. For instance, this vitamin and other members of the B complex are administered intramuscularly regularly to treat pernicious anaemia.

The doctor or nutritionist may advise oral vitamin B12 supplementation or injections as well as increased consumption of foods high in this vitamin when the reason is food and absorption is normal.

Vegetarians must use items fortified with this vitamin, such as soy milk, tofu, and cereals, among others, in their diets.

Since vitamin B12 may be quickly removed from the urine, excess of this vitamin is uncommon. 

However, it is not recommended to take vitamin B12 supplements without consulting a doctor if you have polycythemia, cobalt or cobalamin sensitivities, are recovering from surgery, or are in the postoperative phase.


In this short article, we answered the question “How long to recover from vitamin B12 deficiency?”, and discussed the major causes, signs and treatment of a vitamin B12 deficiency.


Ankar A, Kumar A. Vitamin B12 Deficiency. In: StatPearls. Treasure Island (FL): StatPearls Publishing; June 7, 2021.

Sobczyńska-Malefora A, Delvin E, McCaddon A, Ahmadi KR, Harrington DJ. Vitamin B12 status in health and disease: a critical review. Diagnosis of deficiency and insufficiency – clinical and laboratory pitfalls. Crit Rev Clin Lab Sci. 2021;58(6):399-429. doi:10.1080/10408363.2021.1885339

Pavlov CS, Damulin IV, Shulpekova YO, Andreev EA. Neurological disorders in vitamin B12 deficiency. Ter Arkh. 2019;91(4):122-129. doi:10.26442/00403660.2019.04.000116

Leave a Comment