Vitamin B-12 Test

What is Vitamin B-12?

B-12, also known as cyanocobalamin, is one among the eight different types of the water-soluble Vitamin B, the other seven being thiamine (B-1), riboflavin (B-2), niacin (B-3), pantothenic acid (B-5), pyridoxine (B-6), biotin (B-7) and folate or folic acid (B-9).

When is a Vitamin B-12 test advised?

B-12 deficiency leads to megaloblastic anaemia, nerve impairment, dementia, a tongue condition called glossitis, and a spinal cord disease called myelopathy. It is often associated with thyroid disease and multiple sclerosis. As a result, the following symptoms may be noticed:

Weakness and fatigue

Pale skin

Blurred vision

Heart palpitations


Problems related to nerve damage, such as pins and needles, numbness, tingling, etc.

Mental issues such as depression, memory loss, and confusion.

What causes Vitamin B-12 deficiency?

Vegans and vegetarians are at a disadvantage because of the unavailability of meat sources. Certain conditions and disorders of the body also restrict Vitamin B-12 levels:

Atrophic gastritis, which results in the thinning of the stomach lining.

Pernicious anaemia: Two bodily secretions are involved in the absorption of B-12: hydrochloric acid, which separates the vitamin from the protein that is attached to it, and a protein in the stomach called intrinsic factor, with which it combines to be absorbed by the body. In a condition called pernicious anaemia, the body is unable to produce this intrinsic factor, which reduces its ability to absorb Vitamin B-12 drastically.

Immune system disorders

Small-intestine disorders

In these conditions, tests are recommended.

What are sources of Vitamin B-12?

Vitamin B-12 is found mostly in meats such as poultry, beef, pork, ham, lamb and fish. Dairy products such as milk and cheese are also good sources, as are fortified varieties of soy milk and breakfast cereals.

What are the functions of Vitamin B-12?

B-12 is concerned with the healthy functioning of nervesImageand the production of red blood cells. It also helps make and regulate DNA in the cells.

Vitamin B 12 is also involved in the metabolism through its role in energy production and synthesis of fatty acids.

The recommended intake level per day is 2.4 mcg (micrograms) for teenagers and adults, 2.6 mcg for pregnant women, and 2.8 mcg for lactating women. For children below 13 years, it varies according to their age.

What is the testing procedure?

B-12 levels can be measured through a simple blood serum test. A normal reading would register between 200 ng/ml and 900 ng/ml. If the reading is less than 150 ng/ml, a methylmalonic acid (MMA) test is advised.

However, the blood serum test measures even unusable B-12, giving an insignificant result and covering up an actual deficiency. On the other hand, measuring the concentration of metabolic products such as methylmalonic acid, whose conversion is dependent on Vitamin B-12, gives a clear result. Thus, a rise in the levels of this acid in the blood or in the urine is a confirmatory test for low B-12 levels. Up to 2mg MMA/g of creatine signifies no deficiency, but a higher value is an indication of deficiency. A simple urine test is sufficient for this purpose.

Another test called HoloTC measures just the biologically available B-12 in the blood, and is therefore more reliable than the blood serum test. It measures the amount of B-12 bound to transcobalamin II and is considered an early warning sign of B-12 deficiency. A result higher than 70 pmol/l is normal. If it is between 25 and 70 pmol/l, an MMA test is prescribed.

A test for pernicious anaemia called Intrinsic Factor Blocking Antibody (IFBA) test detects low B-12 levels that result from the body’s inability to produce the intrinsic factor because of the anaemia.

What are the remedies?

Apart from increasing the intake of B-12 rich food, supplements are recommended. If absorption of the vitamin is problematic, oral supplementation may not be as effective. In such a situation, injections are preferred over tablets.

Since deficiency could spell serious interference with the functioning of the nervous system and the brain, it is better to get oneself tested and stay informed about the threat of any potential deficiency. At Apollo Diagnostics, we ensure proper testing procedures and quick results. Find an Apollo Diagnostics centre close to you.

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