Vitamin B12

Name: Vitamin B12
Brand: Thorne
SKU: product-0323
Price: 20.00 GBP
Availability: InStock
Rating: 4.8 (34 reviews)

£20.00

Thorne Vitamin B12 provides methylcobalamin, the active, co-enzyme form of B12 that the body can use directly without conversion.

Active methylcobalamin form, no conversion needed
Supports red blood cell formation and reduces fatigue
Helps maintain healthy nerve function and myelin
Well-suited to plant-based diets and B12 deficiency risk
May support cognitive clarity and mood stability

4.8 (34 reflections)

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ThorneVitamin B12

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About This Product.

Thorne Vitamin B12 provides methylcobalamin, the active, co-enzyme form of B12 that the body can use directly without conversion. This matters because a meaningful portion of people have reduced capacity to convert the more common cyanocobalamin form, particularly those with MTHFR gene variants or compromised digestive function.

B12 plays a central role in red blood cell formation, DNA synthesis, and the maintenance of myelin — the protective sheath around nerve fibres. Deficiency is associated with fatigue, poor concentration, tingling in the extremities, and low mood. It is especially common in people following plant-based diets, older adults (who absorb B12 less efficiently through the gut), and those who take long-term metformin or proton pump inhibitors.

This supplement suits anyone with confirmed low B12 on a blood test, or those in higher-risk groups who want a well-absorbed maintenance dose. The capsule format means it is straightforward to incorporate into a morning routine.

Thorne is a brand our clinicians regard as reliable for manufacturing standards and ingredient quality, and their choice of methylcobalamin over cheaper synthetic forms reflects a formulation philosophy we look for. For anyone uncertain whether B12 is genuinely relevant to them, a simple blood test is the most direct way to find out before supplementing.

Frequently Asked.

Why methylcobalamin rather than cyanocobalamin?

Methylcobalamin is the active co-enzyme form of B12, meaning the body can use it directly. Cyanocobalamin, the form in many cheaper supplements, must first be converted — a step that is less efficient in people with certain genetic variants (such as MTHFR) or poor digestive absorption.

Who is most likely to be B12 deficient?

People following vegan or vegetarian diets, older adults, those with atrophic gastritis or coeliac disease, and long-term users of metformin or proton pump inhibitors are at higher risk. A blood test is the most reliable way to confirm whether supplementation is warranted.

How long before I notice a difference?

This depends on your baseline levels and the reason for supplementing. People correcting a genuine deficiency may notice improvements in energy and concentration within several weeks, though full repletion can take longer. If symptoms persist, revisit with your GP or clinician.

Is it safe to take alongside other B vitamins or a multivitamin?

Generally yes, though it is worth checking whether your multivitamin already contains B12 to avoid unnecessary doubling up. If you are taking other supplements or medications, particularly methotrexate, check with your prescriber.

Can I take this on an empty stomach?

B12 is water-soluble and is generally well tolerated with or without food. Taking it in the morning, with or without a meal, is the most common approach and fits naturally into a daily routine.

Customer Reflections

Overall Sentiment

4.834 reflections

1 – 6 of 34 reflections

Noticeable difference in energy levels

4 months ago

Been taking this for about six weeks now after a blood test showed my B12 was on the low side. Started noticing I wasn't dragging myself through the afternoons anymore. Don't know if it's placebo but I'm inclined to think not — the timing lines up too well. Will keep reordering.

Switched from a cheaper brand

4 months ago

Was on a supermarket own-brand B12 for years and never felt much from it. A friend who works in nutrition suggested switching to methylcobalamin specifically. Can't say it's been dramatic but I do feel steadier — less of that mid-morning fog I'd put down to age.

5 months ago

Vegan for three years and finally took a blood test. My B12 was low. This sorted it out within a couple of months — follow-up test confirmed it. Easy to swallow, no aftertaste.

Good quality but pricey for a single B vitamin

5 months ago

It does what it should — I've had two blood tests confirm my levels are now in range. My only hesitation is the price. Fourteen-odd pounds for one vitamin feels steep, especially when you're taking it alongside other supplements. That said, quality seems solid and I'd rather this than a cheap cyanocobalamin version.

Works well for me

5 months ago

I have an MTHFR variant and was told by my GP to stick to methylated forms of B vitamins. This fits the bill perfectly. Absorbed well, no digestive issues, and my fatigue has noticeably improved over two months of use.

5 months ago

Simple, effective. Takes up no space in my morning supplement routine. Levels back to normal at my last check.

Vitamin B12

About This Product.

How to Take It

Frequently Asked.

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