Fatigue is the symptom nobody takes seriously until it stops going away. You sleep eight hours, you still feel flattened by 3pm and everyone tells you it is just modern life.
Sometimes it is. But low vitamin B12 is a genuinely common and easily missed reason, especially if you follow a plant based diet, take certain long term medications or are over 60.
The supplement aisle does not make this easier. Sprays, drops, nuggets, chewables, tablets, doses ranging from 25 micrograms to 5,000 and labels that all promise the same thing. Here is a plain English guide to what actually matters, plus six UK options worth your money.
Key Takeaways
- The NHS advises that adults aged 19 to 64 need about 1.5 micrograms of vitamin B12 a day, though supplement doses are much higher because absorption from a single dose is limited.
- B12 comes in several forms. Methylcobalamin and adenosylcobalamin are the two coenzyme forms your body uses directly, while cyanocobalamin is cheaper, stable and converted by the body.
- The ingredients list matters as much as the dose. Many products carry bulking agents, sweeteners, flavourings and preservatives alongside the active nutrient.
- The Vegan Society recommends a daily supplement providing at least 10 micrograms, or a weekly one providing at least 2,000 micrograms.
- Testing first is sensible. Fatigue has many causes and B12 is only one of them.
Why Vitamin B12 Matters More Than People Realise
Vitamin B12 is involved in a surprising number of everyday processes. It contributes to normal red blood cell formation, normal functioning of the nervous system, normal energy-yielding metabolism and the reduction of tiredness and fatigue.
The catch is that it is found almost entirely in animal foods. Meat, fish, eggs and dairy are reliable sources, while fruit, vegetables and grains are not.
That makes vegans, vegetarians and anyone eating very little animal produce the most obvious risk group. But absorption also declines with age, and some long term medications interfere with it, so plenty of omnivores end up low too.
How to Judge a B12 Supplement
The form. Methylcobalamin and adenosylcobalamin are the two coenzyme forms the body uses directly. Cyanocobalamin is the cheapest and most stable, and the body converts it into both active forms. Hydroxocobalamin is the form typically used in injections.
The extras. This is where products differ most. Some contain nothing but water and B12, while others include sugar, xylitol, mannitol, flavourings, anti-caking agents and preservatives.
The format. Sublingual drops, sprays and chewables are all designed to be absorbed in the mouth. Which one you pick usually comes down to what you will actually remember to use daily.
The Best Vitamin B12 Supplements in the UK
1. Nature Provides Bioactive B12, 3000 mcg
This is the pick for anyone who reads ingredients lists obsessively, because there is almost nothing to read. Bioactive B12 contains reverse osmosis water and vitamin B12. That is the entire formula.
The B12 itself is a dual coenzyme blend of methylcobalamin and adenosylcobalamin, the two forms your body puts to work without conversion. Most liquid B12 products on the UK market use methylcobalamin alone, so having both coenzyme forms in a liquid is uncommon.
Each 1ml serving delivers 3,000 micrograms, which works out at roughly 13 drops held under the tongue for 30 seconds. A 50ml bottle gives you 50 servings.
It is manufactured in the UK and bottled in Miron violet glass, which filters light to help protect the contents without needing added preservatives. No artificial colourings, no flavourings, no sweeteners.
Best for: People who want the shortest possible ingredients list and both active B12 forms in one bottle.
2. BetterYou Boost B12 Daily Oral Spray
BetterYou is a Barnsley based brandand probably the most recognisable B12 name on British shelves. The daily dose is four sprays, delivering 1,200 micrograms of methylcobalamin.
The 25ml bottle holds 192 sprays, which works out at roughly a 48 day supply. It has a natural apricot flavour and also includes 40 micrograms of chromium plus a small amount of green tea extract.
Worth knowing that it does contain xylitol, citric acid, flavouring and potassium sorbate as a preservative. That is a fair trade if you want something genuinely easy to use.
Best for: People who want a well known brand and a spray they can keep in a bag.
3. Igennus Super B12 Complex Sublingual Spray
Igennus takes an unusual approach by combining three bioactive forms in one spray: methylcobalamin, adenosylcobalamin and hydroxocobalamin. The listed strength is 5,000 micrograms per serving, with 45 servings per bottle.
It is a cherry flavoured liquid spray and is vegan. The three form approach is aimed at people who want maximum coverage rather than a single form.
Best for: Anyone wanting the broadest spread of B12 forms in one product.
4. Viridian High Twelve B-Complex
If your fatigue might involve more than B12 alone, a full B complex makes sense. Viridian is a UK brand and this capsule provides 500 micrograms of B12, split evenly between methylcobalamin and adenosylcobalamin.
Alongside that you get B1, B2, B3, B5 and B6, plus folic acid, biotin, inositol and choline, in a base of alfalfa, spirulina and bilberry. One capsule daily with food.
Best for: People who want the wider B complex rather than B12 in isolation.
5. Solgar Methylcobalamin 1000 µg Nuggets
Solgar has been going since 1947 and these sublingual nuggets are a long standing favourite. Each nugget provides 1,000 micrograms of methylcobalamin and dissolves under the tongue.
The formula does include mannitol as a bulking agent, several anti-caking agents, cellulose gum and natural cherry flavour. It is vegan and widely stocked, which counts for a lot if you want to pick something up locally.
Best for: People who prefer a chewable or dissolving tablet to a liquid.
6. VEG 1 by The Vegan Society
VEG 1 is the budget and simplicity choice. It is a chewable multivitamin developed by The Vegan Society, providing 25 micrograms of B12 as cyanocobalamin alongside vitamin D3, iodine, selenium, B2, B6 and folic acid.
The dose is deliberately modest because it is designed to cover a realistic daily need rather than saturate you. It does contain sugar, which the Society explains is there to make a stable chewable base.
Best for: Vegans who want the four nutrients hardest to get from plants, cheaply, in one tablet.
Test Before You Guess
Here is the part most supplement roundups skip. If you have been flat for months, checking your levels is a far more useful first move than guessing at the pharmacy counter.
Persistent tiredness has a long list of possible causes, and iron, thyroid function and vitamin D are all at least as likely a culprit as B12. Several UK services now offer at home blood testing at reasonable cost.
It is also worth speaking to your GP if you have numbness, pins and needles, memory problems or breathlessness. Those can point to a deficiency that needs proper treatment rather than a shop bought supplement.
Getting the Most From What You Buy
Take it daily rather than occasionally. Absorption from any single dose is limited, so little and often beats a big weekly hit for most people.
Hold sublingual products in your mouth properly. Drops and sprays are designed to sit against the tissue under your tongue or inside your cheek, so swallowing straight away defeats the point.
Finally, do not assume more is always better. NHS guidance is that taking 2mg (2,000 micrograms) or less a day of vitamin B12 in supplements is unlikely to cause harm, and that you should not take more than you need.
The Verdict
For sheer purity, Nature Provides takes it. A two ingredient formula with both coenzyme forms of B12, made in the UK, is a hard combination to beat if you want nothing in the bottle you did not ask for.
If you want convenience above all, BetterYou is the easiest to build a habit around. If you want the widest form coverage, Igennus. If your budget is tight and you eat plant based, VEG 1 does the essential job for very little.
Whichever you choose, consistency matters more than the label. And if the tiredness does not shift after a couple of months, that is a conversation for your GP.
Frequently Asked Questions
How much vitamin B12 do I actually need each day?
The NHS advises that adults aged 19 to 64 need about 1.5 micrograms a day. Supplement doses are far higher than this because the body absorbs only a small proportion of any single dose, so the label figure and the amount you absorb are very different numbers.
Is methylcobalamin better than cyanocobalamin?
Methylcobalamin and adenosylcobalamin are the forms your body uses directly, so they skip a conversion step. Cyanocobalamin is cheaper and more stable, and The Vegan Society notes the body readily converts it into both active forms, which is why it is used in VEG 1.
Do sprays and drops work better than tablets?
Sublingual products are designed to be absorbed through the tissue in the mouth, which appeals to people who struggle with tablets. What matters most in practice is taking something consistently, in a form you find easy to stick with.
Can I take too much vitamin B12?
B12 is water soluble and excess is generally excreted, so problems are uncommon. That said, the NHS points out there is not enough evidence about the effects of high daily doses and advises not taking more than you need, so check with a pharmacist or GP if you are unsure.