Vitamin B Complex UK: B-50 vs B-100, Methylated Forms and Sprays vs Capsules

"Vitamin B complex" is one of the vaguer things you can buy. Two bottles sitting next to each other, both saying B complex, can contain quite different amounts of quite different chemical forms, at prices ranging from £5.99 to £30.99 in our own range.

None of the words on the front — high potency, mega potency, bio‑active, complete, fully active, co‑enzyme — are legally defined terms. All of the useful information is on the back. This guide is about how to read it.

What is actually in the bottle

There are eight B vitamins, and a complex should list all or most of them:

• B1 — thiamin
• B2 — riboflavin
• B3 — niacin
• B5 — pantothenic acid
• B6 — pyridoxine
• B7 — biotin
• B9 — folate, listed as folic acid or as a methylfolate
• B12 — cobalamin

Some products add choline, inositol or PABA. These are not B vitamins in the regulatory sense and have no NRV, so they show a dash rather than a percentage in the table — worth knowing so the gap does not look like a printing error.

What B-50 and B-100 mean

This numbering is a long-standing industry convention rather than a regulated grade. Broadly, a B‑50 delivers around 50mg per serving of the B vitamins that are dosed in milligrams — B1, B2, B3, B5 and B6 — while a B‑100 delivers around 100mg of the same group. The vitamins dosed in micrograms, namely biotin, folate and B12, are scaled separately and do not follow the number.

NOW Foods Vitamin B‑50 is 250 tablets at £14.77 and NOW Foods Vitamin B‑100 is 250 vcaps at £21.22, which is about as clean a comparison of the two as you will find. Natures Aid Vit B Complex 100mg Time Release is 30 tablets at £10.99 and uses the milligram figure directly in its name.

Do not read the number as a quality ranking. It is a strength convention, and a higher number is not automatically the product you want.

Why the NRV percentages look absurd

Open a B complex label and you will see figures like 4,000% NRV. This is normal and it is arithmetic, not hype.

Nutrient Reference Values for the B vitamins are small — the B12 NRV is 2.5 micrograms, the folate NRV is 200 micrograms, the thiamin NRV is 1.1mg. A product containing 100 micrograms of B12 therefore reads as 4,000% NRV, because 100 divided by 2.5 is 40.

The NRV is a labelling reference point that exists to make products comparable on a shelf. It is not a target and not a limit. What it does give you is a fast way to compare two complexes: line up the percentages column and the differences jump out immediately, without needing to convert between milligrams and micrograms.

The forms on the ingredients line

This is where most of the price difference lives, and where the marketing words come from. Each B vitamin can be included in more than one chemical form:

• B12 — cyanocobalamin is the long-standing standard; methylcobalamin and adenosylcobalamin are the forms usually described as "methylated" or "active".
• Folate — folic acid is the conventional form; 5‑MTHF, sometimes under the trade name Quatrefolic, is the methylfolate alternative. Doctor's Best Fully Active B‑Complex with Quatrefolic is 60 vcaps at £14.46.
• B6 — pyridoxine hydrochloride is standard; pyridoxal‑5‑phosphate, written P‑5‑P, is the alternative.
• B2 — riboflavin, or riboflavin‑5‑phosphate.

When a product is called "bio‑active", "fully active" or "co‑enzyme", it is generally signalling that it uses the second option in each of those pairs. Life Extension Bio‑Active Complete B‑Complex is 60 vcaps at £13.99 and NOW Foods Co‑Enzyme B‑Complex is 60 vcaps at £19.99. Those forms cost more as raw materials, which is reflected in the shelf price. Read the ingredients line and you will know exactly which you are buying rather than relying on the adjective.

Our guide to B12 forms and formats goes into more detail on the cobalamins specifically.

Time release and "mega potency"

"Time release" describes a physical coating designed to break down gradually rather than all at once — a formulation choice, and one you will mostly see on higher-strength tablets. "Mega potency" and similar phrases are marketing language with no defined threshold behind them. Check the milligrams.

The formats

B complex is available across essentially every presentation, which means the choice is genuinely yours:

• Capsules — Applied Nutrition Vitamin B Complex, 90 capsules at £12.25; BioTechUSA B‑Complex, 60 capsules at £14.99; Essensey Vitamin B Complex, 90 capsules at £8.99; Addict Sport Nutrition B‑Complex, 90 capsules at £12.99.
• Tablets — NXT Nutrition Vitamin B Complex, 30 tablets at £5.99; Feel Supreme Vitamin B Complex, 60 tablets at £9.99; Dorian Yates Vitamin B Complex, 100 tablets at £11.99.
• Vegetarian capsules — Cytoplan B Complex (High Potency), 60 vcaps at £21.99; KIKI Health Vitamin B Complex, 30 vcaps at £30.99.
• Oral sprays — BetterYou B‑complete Daily Oral Spray, 25ml at £9.99; Osavi B‑Complex Oral Spray, 25ml at £10.99.
• Drops and liquids — Allnutrition B‑Complex Drops, 30ml at £4.99; NOW Foods Vitamin B‑12 Liquid B‑Complex, 59ml at £9.99.

If you are choosing between them, our guide to supplement formats covers how the trade-offs work.

Complex, separates or multivitamin?

The three overlap constantly, and this is the most common way to waste money in the category. Most multivitamins already contain the full B group. If you take one, a B complex on top means you are buying the same eight nutrients twice. Equally, if you only wanted B12, a standalone B12 product will be cheaper per serving than a complex.

Work out which of the three you actually need before comparing prices within one of them. Our multivitamin guide is the right place to start if you are not sure.

Cost per day

The usual sum applies. NOW Foods Vitamin B‑50 at 250 tablets for £14.77, taken one a day, is under 6p a day and over eight months of product. Essensey at 90 capsules for £8.99 is 10p a day. KIKI Health at 30 vcaps for £30.99 is just over £1. All three are B complexes; the range is more than seventeenfold.

Always check units per serving before running it. Some complexes are two capsules a day, which halves the pack life.

One harmless thing worth expecting

Riboflavin is a bright yellow compound, and a noticeably yellow colour in your urine after taking a B complex is simply the riboflavin passing through. It catches people out the first time and it is nothing more interesting than a dye.

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B complexes in capsules, tablets, sprays and drops sit in our Vitamins range, inside the wider Vitamins & Health section, with liquid formats grouped in Liquids & Drops.

A quick note

This article is general information, not medical or nutritional advice. Food supplements are not a substitute for a varied, balanced diet and a healthy lifestyle, and should not be used to prevent or treat any illness. Always read the product label, do your own research, and speak to a qualified doctor, pharmacist or registered nutritionist before starting a new supplement — especially if you are pregnant, breastfeeding, under 18, taking medication or managing a health condition.