What is the role of Transcobalamin II in vitamin B12 metabolism?

What is the role of Transcobalamin II in vitamin B12 metabolism?

Vitamin B12 is transported to the tissues attached to a plasma-binding protein — transcobalamin II. Transcobalamins I and III bind the greater proportion of plasma vitamin B12 but does not liberate it efficiently. The function of salivary transcobalamin I is to protect cobalamin from acid degradation in the stomach.

What is normal range for vitamin B12 pmol L?

Normal Results Normal values are 160 to 950 picograms per milliliter (pg/mL), or 118 to 701 picomoles per liter (pmol/L). Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or may test different samples.

What is cyano cobalamin used for?

Cyanocobalamin is a manufactured version of vitamin B12. It’s used to treat and prevent vitamin B12 deficiency anaemia (when you have low levels of this vitamin in your body).

Can lansoprazole affect B12?

Lansoprazole reduces the stomach acid needed to absorb vitamin B12. When taken for long periods of time, lansoprazole may raise your risk of vitamin B12 deficiency, which may cause symptoms including anemia, weakness, confusion, balance problems and nerve damage, leading to tingling and numbness in your hands and feet.

What is Transcobalamin II deficiency?

Transcobalamin II deficiency is a rare autosomal recessive disorder causing intracellular cobalamin depletion, which in turn causes megaloblastic bone marrow failure, accumulation of homocysteine and methylmalonic acid with clinical findings of failure to thrive, diarrhea, vomiting, pancytopenia, megaloblastic anemia.

Is cobalamin the same as B12?

Vitamin B12, also called cobalamin, is one of 8 B vitamins. All B vitamins help the body convert food (carbohydrates) into fuel (glucose), which is used to produce energy.

What is a good B12 level?

Understanding the Results But a normal level of vitamin B12 in your bloodstream is generally between 190 and 950 picograms per milliliter (pg/mL). Between 200 to 300 pg/mL is considered borderline and your doctor may do more testing. Below 200 pg/mL is low and more testing is needed.

What B12 level is too high?

An abnormally high vitamin B-12 status is anything over 900 pg/mL. This result may suggest liver or kidney problems, diabetes, or certain forms of leukemia.

What is the difference between cyano cobalamin and methylcobalamin?

Cyanocobalamin is a synthetic form of vitamin B12 found only in supplements, while methylcobalamin is a naturally occurring form that you can get through either food sources or supplements.

Can GERD cause B12 deficiency?

Some studies have found an association between heartburn medications and increased risk of vitamin B-12 deficiency. Medicines to treat heartburn, also called gastroesophageal reflux disease (GERD), work by suppressing stomach acid. Blocking stomach acid and other secretions may also block B-12 absorption.

Does B12 deficiency cause acidity?

Also, medications that help to reduce indigestion (acidity) can result in B12 deficiency because acid is needed to absorb B12. Older people are more likely to have deficiencies as a result of a reduction in stomach acid production.

What should I know about cobalamin before taking it?

Clinicians should be aware of possible adverse effects, such as allergy and anaphylaxis. So precautions should be taken, and the intradermal test is necessary if an allergy is suspected. Patients should be educated about the disease and management because some patients may discontinue cobalamin once they feel better.

What is the pathophysiology of cobalamin deficiency?

In children with inherited cobalamin-related diseases, the damage is limited to the brain and characterized by white matter loss with delayed myelination; MRI has also revealed delayed myelination in infants with nutritional cobalamin deficiency [63].

How is cobalamin produced in the human body?

Cobalamin from biological sources is provided in the coenzyme form (5′-adenosylcobalamin) as a protein-vitamin complex, through non-specific protein-vitamin binding. At the low pH of the stomach, proteolytic digestion by pepsin occurs, which is the prerequisite for cobalamin release.

What are the rarest disorders of cobalamin transport?

The most clinically significant among the rare disorders of cobalamin transport is transcobalamin II deficiency, which causes megaloblastic anemia in infancy and is associated with normal cobalamin concentrations.