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Active Vitamin B12 (Holotranscobalamine)

Also referred as

Vitamin B12

Active Holo Transcobalamine

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The Active Vitamin B12 (Holotranscobalamine) test measures the level of holotranscobalamin (HoloTC), the biologically active form of vitamin B12 in the blood. It is more sensitive than standard B12 tests and can detect deficiency at an early stage.

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Understanding Active Vitamin B12 (Holotranscobalamine)

Vitamin B12 is an important vitamin that helps the body make red blood cells, supports nerve function, keeps your energy levels up, and helps in cell metabolism. It also plays a key role in making DNA, which carries your body's genetic information. This vitamin is especially important for keeping the brain and nervous system healthy. A deficiency in vitamin B12 can lead to serious health issues such as anemia, nerve damage, and cognitive difficulties.

Vitamin B12 exists in two forms in the blood: active and inactive. The active form, known as holotranscobalamin (HoloTC), is the part of vitamin B12 that is bound to a transport protein called transcobalamin II. This is the only form that can be taken up and used by the cells of the body. The inactive form, bound to a different protein (haptocorrin), cannot enter cells and has no biological activity.

The Active Vitamin B12 (Holotranscobalamine) test measures just the biologically active portion of vitamin B12 in the blood. This makes it a more sensitive and reliable test for detecting an early deficiency.

The Active Vitamin B12 (Holotranscobalamine) test is often done when there are signs or symptoms of vitamin B12 deficiency, such as fatigue, weakness, numbness or tingling in the hands and feet, balance problems, memory loss, mood changes, or pale skin. It is also done in people who are at risk of low vitamin B12 levels, such as older adults and individuals following a strict vegetarian or vegan diet. This test is also useful to monitor digestive conditions like Crohn’s disease and celiac disease. In pregnancy, this test may be used to check if the mother has enough vitamin B12 to support the baby’s development. It can also be done to monitor the effectiveness of vitamin B12 treatment or to help diagnose the cause of certain types of anemia or nerve problems.

No special preparation is required for this test. However, it is important to inform the doctors about any medications or supplements that may affect the results.

Test result ranges are approximate and may differ slightly between labs. Talk to the doctor about specific test results. The results will help them determine the medical condition and formulate an overall treatment plan. They may suggest lifestyle recommendations, vitamin B12 supplements, or further testing if required to manage the condition.

Please note: This is an outsourced test. The sample for this test is collected by TATA 1MG and processed at a NABL accredited partnered lab.

What does Active Vitamin B12 (Holotranscobalamine) measure?

The Active Vitamin B12 (Holotranscobalamine) test measures the level of holotranscobalamin, the active form of vitamin B12 that is absorbed and used by the body’s cells. This test provides a more precise and sensitive evaluation of the body’s usable vitamin B12 compared to total B12 tests, which also measure inactive forms. Low active B12 levels can indicate that the body is not receiving enough functional B12, even if total B12 levels appear normal. This test can serve as an early warning sign of deficiency, which may impact blood health and nerve function.

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FAQs related to Active Vitamin B12 (Holotranscobalamine)

What is the Active Vitamin B12 (Holotranscobalamine) test?

The Active Vitamin B12 (Holotranscobalamine) test measures the level of the active form of vitamin B12 in your blood. This is the form that your body can actually use. It helps check if you have a vitamin B12 deficiency.

Why do I need this test?

You may need this test if you have symptoms like tiredness, weakness, numbness in your hands or feet, memory problems, or trouble with balance. It’s also used to check for B12 deficiency in people at risk, like older adults, vegans, or those with digestive issues.

How is this test different from a regular B12 test?

A regular B12 test measures the total amount of B12 in your blood, including both active and inactive forms. The Active Vitamin B12 (Holotranscobalamine) test only measures the usable form of B12, giving a more accurate picture of your body’s vitamin B12 status.

Do I need to fast before taking the Active Vitamin B12 (Holotranscobalamine) test?

No fasting is required for this test. You can schedule it at your convenience without avoiding food or water beforehand.

How often should I get tested for the Active Vitamin B12 (Holotranscobalamine) test?

The frequency of Active Vitamin B12 (Holotranscobalamine) testing depends on your individual health status and risk factors. Your doctor may recommend the test if you have symptoms of deficiency or are at higher risk due to factors like age, diet, or certain medical conditions.

What do low active B12 levels mean?

Low levels of active B12 can mean that your body is not getting enough usable vitamin B12. This can be an early sign of a deficiency that could affect your blood health and nervous system.

What is the cause of vitamin B12 deficiency?

Deficiency of vitamin B12 could be due to poor dietary intake, pernicious anemia (as it leads to poor absorption of vitamin B12), and certain types of stomach-related surgeries, such as weight loss surgery or any surgery of the intestines.

Can I improve my vitamin B12 levels?

Yes, vitamin B12 levels can often be improved with dietary changes, supplements, etc., depending on your doctor’s recommendations.

What are the risks associated with vitamin B12 deficiency?

The risks associated with vitamin B12 deficiency are memory loss, confusional states, paranoia (especially in elderly patients), infertility, heart diseases, including heart failure (in severe cases of anemia), pregnancy complications and birth defects, and stomach cancer.

What are some of the common food sources of vitamin B12?

Some common food sources of vitamin B12 include fish, red meat, eggs, dairy products like milk, cheese, and yogurt, as well as fortified cereals and soy or rice milk.

How can I raise my vitamin B12 levels naturally?

Always consult your doctor if your vitamin B12 levels are lower than normal. However, incorporating foods rich in vitamin B12, such as meat, fish, milk, soy products, and fortified breakfast cereals, can help raise your vitamin B12 levels naturally.

Is vitamin B12 important during pregnancy?

Yes, vitamin B12 is essential during pregnancy because it helps in the development of the baby’s brain and nervous system. Adequate B12 levels also support the mother's red blood cell production and energy levels. A deficiency during pregnancy can lead to complications like anemia, fatigue, or even developmental problems in the baby.

How does Tata 1mg ensure accurate lab test results?

Tata 1mg ensures accurate lab test results through certified laboratories. Tata 1mg uses advanced technology and adheres to stringent quality control measures. This commitment to high standards guarantees reliable results.

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Last Updated

9th Nov 2025