Which form of vitamin B12 is best?

The two most common forms of vitamin B12 are methylcobalamin and cyanocobalamin. Most vitamin B12 supplements are in the form of methylcobalamin. This is because the body absorbs methylcobalamin better than cyanocobalamin. Other than that, methylcobalamin stays longer in the body in comparison to cyanocobalamin. Methylcobalamin is the active form of vitamin B12. Better absorption and stays longer in the human body results in better positive effects for patients. Mecobalamin or methylcobalamin is used to treat anemia and peripheral neuropathies. Mecobalamin contains vitamin B12 which is one of the vitamins that are required by the human body. Vitamin B12 plays a vital role in the production of red blood cells or erythrocytes.

Mecobalamin should not be taken with certain medications as the medications may reduce the effectiveness, absorption, and the level of vitamin B12 in the body. The medications that may cause negative interactions with mecobalamin are:

  • Proton pump inhibitors like pantoprazole
  • Neomycin
  • Certain antihistamines
  • Chloramphenicol
  • Aminosalicylic acid
  • Colchicine
  • A large dose of folic acid

Peripheral neuropathy or better known as polyneuropathy is a disease affecting peripheral nerves. Causes of peripheral neuropathies are:

  1. Diabetes mellitus
  2. HIV infection
  3. Kidney disease
  4. Hypothyroidism
  5. Vitamin B12 and folate deficiencies
  6. Amyloidosis
  7. Lyme disease
  8. Guillain-Barre syndrome
  9. Alcohol, chemotherapy, or heavy metals toxicities

Detection of the underlying cause of peripheral neuropathies is really important so that the right treatment can be administered. Replacement of vitamin B12 or mecobalamin is the key in treating peripheral neuropathy due to vitamin B12 deficiency. History taking, physical examinations, and tests are extremely required to conclude a final diagnosis before a treatment can be given. No matter what symptoms you are having, please visit a doctor for an opinion and if you require treatment, the right treatment can be given early.

Tablets or capsules of mecobalamin should be stored below 30 degrees celsius, while the injection solution must be stored between 2 to 8 degrees celsius. Mecobalamin should not be exposed to direct sunlight. The possible side effects of taking methylcobalamin are:

  • Vomiting
  • Diarrhoea
  • Abdominal pain
  • Nausea
  • Excessive sweating
  • Pain at the injection site
  • Itchiness at the site of injection
  • Burning sensation over the body parts where the mecobalamin was injected

Megaloblastic anemia is a term used for macrocytic anemia that is characterized by impaired DNA synthesis in the red blood cells. This is usually caused by a lack of vitamin B12, folate, or copper. Ingestion of certain medications may also cause this.

Megaloblastic anemia is one of the examples of macrocytic anemia. Macrocytic anemia is anemia in which the size of the red blood cells is abnormally large. Other types of anemia based on the size of the red blood cells are normocytic anemia and microcytic anemia. Normocytic anemia is when the red blood cells are normal in size, while microcytic anemia is when the red blood cells are small.

 The causes of macrocytic anemia (large red blood cells) are:

  • Hemolytic anemia (burst or rupture of red blood cells)
  • Recovery from bleeding
  • The recovery of bone marrow following a chemotherapy
  • Increase red blood cells after patients were given iron or folate or vitamin B12 or erythropoietin
  • Lack of vitamin B12
  • Low level of folate
  • Liver disease
  • Pregnancy
  • Human immunodeficiency virus (HIV) infection
  • Hypothyroidism

Mecobalamin can be given orally, through intramuscular (IM) injection, or via intravascular injection (IV). The dose varies depending on the disease, age, and severity of the symptoms. Mecobalamin should be with caution in pregnancy and lactating mother. Physicians will decide whether it is required to be used by pregnant patients or by patients who are breastfeeding. Mecobalamin should not be consumed with the consumption of alcohol as alcohol intake will reduce the absorption of the vitamin B12 and the given doses will not be enough to deliver the expected effect.