Medicine
Fact Checked

What Factors Affect B12 Injection Dosage?

Emma Miller
Emma Miller

Low levels of vitamin B12 in the body are often treated with injections. There are many causes of low levels of B12 and these can include malabsorption issues in the small intestine, adherence to a strict vegan diet, and intake of anti-diabetic medications. The most common cause of vitamin B12 deficiency is the autoimmune disorder known as pernicious anemia. The main factor that usually determines B12 injection dosage is the level of this vitamin in the body, as determined by a blood test. Pregnancy may increase the need for supplemental B12 and dosage adjustments may be needed during this time.

Low levels of B12 are commonly seen in people over age 65 and in those suffering from pernicious anemia. Adequate levels of this vitamin are necessary for normal neurological function and for the conversion of nutrients into energy in the body. Deficiency may lead to a range of neurological symptoms and hematologic abnormalities.

Pernicious anemia is the most common cause of vitamin B12 deficiency.
Pernicious anemia is the most common cause of vitamin B12 deficiency.

Diagnosis of B12 deficiency is generally simple and done by measuring the levels of B12 in the blood. Serum levels of the vitamin are typically the main factor affecting B12 injection dosage. The lower the blood levels, the higher the supplemental B12 dose. In some cases, B12 supplementation may be discontinued after blood levels normalize. For most people, however, supplementation is ongoing.

Low levels of B12 are commonly seen in people age 65 or older.
Low levels of B12 are commonly seen in people age 65 or older.

Supplementation therapy is generally given via intramuscular injection, at a dose of 1,000 to 2,000 micrograms (mcg) daily for up to two weeks. This generally leads to a rapid increase of blood B12 levels. The common, long-term maintenance dosage ranges from 100 to 1,000 micrograms, administered once a month. Blood tests are normally done every few months to monitor levels during treatment. This usually helps ensure the correct B12 injection dosage is given.

Unprocessed beef contains large quantities of vitamin B12.
Unprocessed beef contains large quantities of vitamin B12.

Pregnancy can affect the levels of B12 in the body. People who require long-term B12 therapy should undergo regular testing during this time, as their B12 injection dosage may need to be adjusted. The body’s nutrient requirements typically go back to normal in the months following pregnancy, so B12 injection dosage may need to be changed accordingly.

Some diabetic medications can cause patients to become deficient in vitamin B12.
Some diabetic medications can cause patients to become deficient in vitamin B12.

Intake of certain medications may affect a person’s B12 injection dosage. Regular use of proton pump inhibitors, antacids, or some anti-diabetic drugs, such as metformin, may lead to decreased blood levels of B12 as they alter the way the vitamin is absorbed. Normal absorption resumes when the medications are discontinued, but people on long-term therapy with these drugs may need a higher B12 injection dosage for the duration of treatment.

You might also Like

Discuss this Article

Post your comments
Login:
Forgot password?
Register:
    • Pernicious anemia is the most common cause of vitamin B12 deficiency.
      By: joshya
      Pernicious anemia is the most common cause of vitamin B12 deficiency.
    • Low levels of B12 are commonly seen in people age 65 or older.
      By: wildworx
      Low levels of B12 are commonly seen in people age 65 or older.
    • Unprocessed beef contains large quantities of vitamin B12.
      By: Blind Shot
      Unprocessed beef contains large quantities of vitamin B12.
    • Some diabetic medications can cause patients to become deficient in vitamin B12.
      By: dalaprod
      Some diabetic medications can cause patients to become deficient in vitamin B12.
    • Blood tests may be performed every few months during treatment of low B12 levels.
      By: Alexander Gospodinov
      Blood tests may be performed every few months during treatment of low B12 levels.
    • Patients experiencing pernicious anemia may be more likely to develop vitiligo, a condition that reduces the amount of melanin in the skin.
      By: Axel Bueckert
      Patients experiencing pernicious anemia may be more likely to develop vitiligo, a condition that reduces the amount of melanin in the skin.
    • Regular use of antacids may lead to decreased blood levels of B12.
      By: stormy
      Regular use of antacids may lead to decreased blood levels of B12.