B12, which form is better?
B12 Methylcobalamin vs Hydroxocobalamin: What’s the Difference?
Vitamin B12 is an essential nutrient involved in red blood cell formation, neurological health, DNA synthesis, and energy production. While it’s commonly referred to simply as “B12,” there are several different forms available clinically. The most frequently used are form that is funded in New Zealand is hydroxocobalamin, but a preferred form of B12 amongst natural health practitioners is Methylcobalamin.
Understanding the differences between these forms can help explain why one may be preferred over another depending on a person’s genetics, absorption capacity, and clinical needs.
Methylcobalamin: The Active, Methylated Form
Methylcobalamin is a bioactive (ready-to-use) form of vitamin B12. This means it does not require conversion in the body before it can be utilised at a cellular level.
Key benefits of methylcobalamin:
Highly bioavailable – readily absorbed and used by the body
Directly supports methylation pathways, which are critical for detoxification, neurotransmitter production, and DNA repair
Supports neurological health, nerve repair, and cognitive function
Particularly beneficial for:
People with MTHFR gene mutations: Individuals with MTHFR variants often have reduced ability to methylate nutrients efficiently. Because methylcobalamin is already methylated, it bypasses this limitation and is often better tolerated and more effective.
Pernicious anaemia: In this condition, intrinsic factor is lacking, meaning B12 cannot be absorbed through the gut. Injectable methylcobalamin provides a bioavailable form that does not rely on gastrointestinal absorption.
Those with chronic fatigue, neurological symptoms, or high B12 demand, where efficient cellular uptake is important.
Because of its high bioavailability and direct activity, methylcobalamin is often considered the gold standard form of B12 when optimal absorption and clinical effect are the priority.
Hydroxocobalamin: A Stable and Cost-Effective Option
Hydroxocobalamin is a synthetic, laboratory-made form of vitamin B12 that has been widely used in medical settings for decades, particularly as an injectable.
Key characteristics of hydroxocobalamin:
Synthetic and laboratory-produced, allowing for consistent formulation at scale
Highly stable, with a longer half-life in the body
Converts to active forms (methylcobalamin and adenosylcobalamin) after administration
Commonly used in hospital and primary care settings
Why it’s so widely used:
Hydroxocobalamin is often favoured because it is:
Cost-effective to manufacture
Long-acting, meaning injections may be needed less frequently
Well-established, with extensive clinical history and familiarity among healthcare providers
For many individuals, hydroxocobalamin is an effective and reliable option for correcting B12 deficiency, particularly in standard treatment protocols.
Methylcobalamin vs Hydroxocobalamin: A Quick Comparison
Methylcobalamin is often the preferred choice when:
Optimal absorption is needed
Methylation support is a priority
There are known MTHFR mutations
Neurological symptoms or pernicious anaemia are present
Hydroxocobalamin remains a valuable option when:
Cost is a consideration
A longer-acting injectable is desired
Standard B12 deficiency is being treated effectively
In clinical practice, the choice should be guided by biochemistry, genetics, symptoms, and treatment goals.
Vitamin B12 is not one-size-fits-all. While hydroxocobalamin is widely used due to its stability and cost-effectiveness, methylcobalamin offers superior bioavailability and targeted support for methylation and neurological health. For individuals with genetic variations such as MTHFR mutations or conditions like pernicious anaemia, methylcobalamin is often the more effective and better-tolerated option.
Methylcobalamin is classed as a section 29 medicine in New Zealand, and therefore cannot be advertised. If you’re unsure which form is right for you, speak with a qualified holistic healthcare professional, such as our team at The Nutrient Nurse, who can tailor B12 therapy to your individual needs.
