Buying vitamin B12: price per month, not per µg

12 August 2026

The short answer: with vitamin B12, price per microgram is the least useful figure you can pick. Anyone comparing two tins almost automatically works out how many micrograms they get for a euro — and with B12 that is exactly what leads in the wrong direction. The reason lies in absorption: above a few micrograms, the body takes up only about one per cent of every additional amount. So the 5,000 µg tablet does not deliver five times what the 1,000 µg tablet does, but a few micrograms more.

A pack becomes comparable through a different number: how many days it covers — and from that, the price per month. On top of that come three things on the label that can be checked in ten seconds: the amount per daily portion, the form in the ingredients list, and the mandatory particulars every food supplement has to carry in the EU.

Why the microgram figure is not a price comparison

Vitamin B12 has two routes into the body. The active route via intrinsic factor is the good one, but the small one: it is exhausted at roughly 1.5 µg per meal. Everything above that only seeps passively through the gut wall, at an order of magnitude of one per cent of the amount. From 1,000 µg that makes around 10 µg — more than the 2 to 6 µg an adult loses daily according to EFSA estimates, but not 1,000 µg. How this works in detail is set out in Vitamin B12 absorption.

For the purchase, an inconvenient piece of arithmetic follows. If a manufacturer quintuples the amount per tablet, what arrives does not quintuple — only the share that was already the smaller remainder grows. The microgram figure is therefore not a performance statement but a design decision: it says with what safety margin the manufacturer serves the passive route.

The nutrient reference value on which the percentage on the pack hangs is 2.5 µg per day (Regulation (EU) No 1169/2011, Annex XIII). A 1,000 µg tablet therefore lands at 40,000 % — a figure that has to be on the label and says nothing about the benefit.

The number that counts: how long the tin lasts

The reach of a pack follows from the number of tablets and the recommended daily portion stated on the tin — not from what you might make of it yourself.

Price per day = pack price ÷ tablets per pack × tablets per day

Price per month = price per day × 30

Three invented but typical packs show how far the two figures diverge:

Pack	Price	Tablets	µg per tablet	Price per 1,000 µg	Lasts	Price per month
A — high dose	€14.90	60	5,000 µg	€0.05	60 days	€7.45
B — standard	€12.90	180	1,000 µg	€0.07	180 days	€2.15
C — lozenge	€24.90	120	1,000 µg	€0.21	120 days	€6.23

By price per microgram, pack A wins clearly — on paper it is a third cheaper than B. By price per month it costs three and a half times as much. The micrograms A is praised for are precisely the ones of which about one per cent arrives; the days B covers, by contrast, count in full.

Two pitfalls sit in the same calculation. First: if the tin says "2 tablets daily", the reach halves — and the number of tablets on the front loses its meaning. Second: large packs almost always lower the price per day, but only if the shelf life plays along.

When one tablet is meant to cover several days

Because the passive route does not saturate, schemes in which larger amounts are taken at longer intervals also work — around 2,000 µg weekly in trials. Arithmetically, that extends the reach of a tin many times over: 180 tablets then last not half a year but over three years.

Only this is not a purchasing decision. The recommended daily portion on the pack is a mandatory particular, and the note "the stated recommended daily dose must not be exceeded" is not there for decoration either. Anyone taking B12 on a rhythm other than the declared one does so within the framework of medical advice — not to push down the price per month. For comparing two tins on the shelf, the statement on the label therefore always applies.

The form is in the ingredients list, not the nutrition table

Four cobalamins are approved as a B12 source in food supplements: cyano-, hydroxo-, methyl- and 5-deoxyadenosylcobalamin (Directive 2002/46/EC, Annex II). Which of them is in the tablet is revealed by the ingredients list — the nutrition table only names "vitamin B12" in micrograms and the percentage of the reference value. What separates the forms chemically and what the body makes of them is set out in Vitamin B12 forms.

Two things matter for the wallet. First, "bioactive" or "activated" is not a legally defined term; it describes the raw material used, not a result. Second, the raw-material premium for methylcobalamin over cyanocobalamin is real but small — it moves in the range of a few cents per daily portion. If a pack is advertised with "coenzyme form" and costs three times as much per month, the premium is not coming from the raw material.

Lozenge, spray, drops: does sublingual pay off?

Dosage forms that dissolve in the mouth are regularly advertised with better absorption and are almost always more expensive. The evidence on this is unusually clear.

A controlled trial in 30 people with B12 deficiency compared 500 µg daily sublingually against the same amount swallowed. After four weeks, serum levels stood at 288 pmol/l (sublingual) and 286 pmol/l (oral) — both groups rose markedly, and no difference between them could be established (Sharabi et al., British Journal of Clinical Pharmacology 2003). A 2025 systematic review with meta-analysis covering 25 studies and 6,098 participants reached the same result: no statistically significant difference between sublingual and oral administration.

That makes the question one of preference rather than efficacy: anyone who struggles to swallow tablets or finds a lozenge more pleasant has a good reason for the more expensive form. A premium on absorption is not what is being paid for.

The mandatory particulars as a ten-second check

What has to appear on a food supplement pack in the EU is set out in Articles 6 and 8 of Directive 2002/46/EC, transposed into national law in every member state — in Germany as § 4 of the Nahrungsergänzungsmittelverordnung. If something is missing, that is not a detail but a sign of a product not intended for this market:

• the designation "food supplement"
• the categories of nutrients characteristic of the product
• the recommended daily portion
• the amount of the nutrient per daily portion and the percentage of the reference value
• the statement that the recommended daily dose must not be exceeded
• the statement that the product is not a substitute for a balanced and varied diet
• the note to store out of the reach of young children

The same directive expressly prohibits labelling that states or implies that a balanced, varied diet cannot provide appropriate quantities of nutrients in general. A product page claiming exactly that is selling past the legal position.

Bought twice: where B12 is already included

Vitamin B12 is in many preparations no one perceives as a B12 product: in multivitamins, in B complexes, in iron and folic acid combinations — and outside the supplement shelf in fortified plant drinks, breakfast cereals and energy drinks. Before buying, it is therefore worth a look in your own cupboard: anyone already taking a B complex may, with an additional B12 tin, be buying a second cover for the same gap.

The reverse case is the more common mis-purchase: a multivitamin with 2.5 µg B12, bought to close a genuine supply gap. That amount covers the reference value and does not reckon with the passive route — for someone on a purely plant-based diet or with impaired absorption it is therefore something other than a high-dose single tablet.

Shelf life, packaging, pack size

The year's supply is only cheaper if it also lasts a year. The rule of thumb is simple: the reach must not exceed the remaining time until the best-before date. With offers carrying a short best-before date, the low price per month is a calculation you only cash in on paper.

On packaging: methyl- and adenosylcobalamin are more light-sensitive than cyanocobalamin. In an opaque tin the matter is settled; a transparent pouch on the windowsill is not. And as with every food supplement: a certificate of analysis on request is a good sign, an advertising statement about purity without evidence is not.

What we stock

Our tablet contains 1,000 µg vitamin B12 as methylcobalamin, intended for one intake a day — 180 tablets therefore cover 180 days, which reduces the "price per month" calculation to a single division: Vitamin B12 1000 µg.

Further strengths and combinations are listed side by side in the vitamin B12 category.

Among the claims authorised for vitamin B12 are these: Vitamin B12 contributes to normal energy-yielding metabolism. Vitamin B12 contributes to normal functioning of the nervous system. Vitamin B12 contributes to normal red blood cell formation. Vitamin B12 contributes to the reduction of tiredness and fatigue. (Regulation (EU) No 432/2012). Food supplements are not a substitute for a balanced and varied diet and a healthy lifestyle.

Frequently asked questions

Is 1,000 µg per tablet too much for daily use? EFSA has not derived a Tolerable Upper Intake Level for vitamin B12, because the available data did not yield a threshold for harmful effects. Germany's Federal Institute for Risk Assessment proposes 25 µg per daily portion to the legislator as a maximum level — a proposal, not a limit in force.

Is the big tin always worth it? Almost always on price per month — but only if the best-before date carries the reach and the intake is planned for the long term. Anyone taking B12 only for a limited period pays, with the year's supply, for tablets that grow old in the cupboard.

Do I have to pay more for methylcobalamin? A premium is usual and justified, because the raw material is more expensive and more sensitive. It should, however, stay in the range of a few cents per day. A multiple of the price cannot be explained by the form — at that point you are paying for the wording.

How do I spot an offer I should leave on the shelf? By three things: missing mandatory particulars, a form that appears nowhere in the ingredients list, and advertising with effects that go beyond the authorised claims. Price is the weakest indicator here — expensive does not mean good, cheap does not mean bad.