Magnesium and Vitamin B6 — Why They're Taken Together

Key takeaways

Magnesium and vitamin B6 are often combined in one supplement because they don’t compete for absorption and B6 acts as a cofactor that supports how the body uses magnesium. Both have authorised UK health claims: each contributes to normal psychological function, normal nervous-system function, and the reduction of tiredness and fatigue, while vitamin B6 also contributes to the regulation of hormonal activity. The forms matter — magnesium glycinate is gentle on the stomach, and B6 as P5P is the body-ready form. Speak to a GP before supplementing.

If you’ve noticed magnesium and vitamin B6 keep appearing together — in the same tablet, sachet or capsule — there’s a reason beyond marketing. This guide explains why the two are paired, what each is actually authorised to do in the UK, why the form of each ingredient changes what you’re getting, and how to read a label so you’re comparing like for like. For the wider picture on how magnesium fits a women’s formula, our guide to which form of magnesium matters is a useful companion.

Why are magnesium and vitamin B6 taken together?

Magnesium and vitamin B6 are combined because the two work in the same systems and don’t interfere with each other’s absorption. Vitamin B6 acts as a cofactor — a helper nutrient — in many of the enzyme reactions that also depend on magnesium, so the two are biochemically linked rather than simply bundled for convenience. Both are also nutrients a lot of people under-consume from diet alone, and both carry overlapping authorised claims around energy, the nervous system and psychological function. Putting them in one product means one daily step instead of two. What the combination does for a specific health concern is a question for a healthcare professional, not a label — below, we stick to what each nutrient is authorised to say.

What does magnesium do? The authorised UK claims

Magnesium is an essential mineral involved in hundreds of processes in the body. Under GB rules, magnesium may carry these authorised health claims, among others, when a product contains a significant amount:

• Magnesium contributes to a reduction of tiredness and fatigue
• Magnesium contributes to normal energy-yielding metabolism
• Magnesium contributes to normal functioning of the nervous system
• Magnesium contributes to normal muscle function
• Magnesium contributes to normal psychological function
• Magnesium contributes to electrolyte balance
• Magnesium contributes to the maintenance of normal bones and teeth

Those are the claims a UK supplement is permitted to make about magnesium, worded as they appear on the register. Anything beyond them — “boosts”, “cures”, or claims about a named condition — isn’t authorised. UK adults aged 19–64 need roughly 270–300 mg of magnesium a day, ideally from food; supplements are for topping up, not replacing a varied diet.

What does vitamin B6 do? The authorised UK claims

Vitamin B6 (pyridoxine) is a water-soluble vitamin the body can’t store for long, so a regular intake matters. Its authorised GB health claims include:

• Vitamin B6 contributes to the regulation of hormonal activity
• Vitamin B6 contributes to normal psychological function
• Vitamin B6 contributes to the reduction of tiredness and fatigue
• Vitamin B6 contributes to normal functioning of the nervous system
• Vitamin B6 contributes to normal energy-yielding metabolism
• Vitamin B6 contributes to normal red blood cell formation
• Vitamin B6 contributes to the normal function of the immune system

The first of those — contributes to the regulation of hormonal activity — is the claim that makes B6 a common addition to supplements aimed at women. It’s stated exactly as authorised; we’re not adding anything to it. Where the overlap with magnesium is clearest is the three claims they share: normal psychological function, normal nervous-system function, and reduction of tiredness and fatigue.

Does the form matter? Magnesium glycinate and B6 as P5P

Yes — the chemical form of each ingredient affects tolerability and how usable it is, and it’s where many products quietly differ. Magnesium is always bound to something else, and that partner changes its character: magnesium glycinate (magnesium bound to the amino acid glycine) is well tolerated and gentle on the stomach, whereas cheaper forms such as magnesium oxide are less well absorbed and more likely to have a laxative effect. The number that matters on the label is the elemental magnesium — the actual magnesium content — not the larger compound weight, which can make a product look higher-strength than it is.

Vitamin B6 comes in two main forms too: standard pyridoxine, and P5P (pyridoxal-5-phosphate), which is the active, body-ready form. Our own Belle Balance (disclosing plainly that it’s ours) uses magnesium glycinate and B6 as P5P for exactly these reasons — it’s a hormonal-balance drink mix that includes both nutrients alongside inositol. Plenty of other products combine magnesium and B6; the differences to check are the forms and the elemental amounts, which we cover next.

How to choose a magnesium and B6 supplement in the UK

Comparing labels rather than front-of-pack marketing, four things separate one magnesium-and-B6 product from another:

• Elemental magnesium, not compound weight. “1,500 mg magnesium bisglycinate” is not 1,500 mg of magnesium — check the elemental figure, which is often a fraction of the headline number. This is the same “dose on the label vs dose you get” trap we cover in our guide to reading a supplement dose.
• Form. Glycinate (or another chelated form) for tolerability; P5P for the body-ready form of B6.
• Sensible B6 amount. More is not better with B6 — it has an upper safe level, so a modest amount within guidelines is the sign of a well-formulated product, not a weakness.
• Transparency. A full label with every amount disclosed, no proprietary blends, third-party testing, and a format you’ll take consistently.

If you’re considering magnesium or B6 for a specific health reason — hormonal, sleep, or otherwise — that decision belongs with your GP or pharmacist, not a supplement label. The NHS guide to vitamins and minerals is a good neutral starting point, and you can see the authorised claims we work within on our health claims references page.

Frequently asked questions

Can you take magnesium and vitamin B6 together?

Yes. Magnesium and vitamin B6 don’t compete for absorption, which is why many UK supplements combine them in a single tablet, capsule or sachet. Vitamin B6 also acts as a cofactor in reactions that use magnesium. If you take other medicines, check with a pharmacist first, as magnesium can interact with some.

What is magnesium and B6 good for?

Under UK rules, magnesium and vitamin B6 both contribute to normal psychological function, normal functioning of the nervous system, and the reduction of tiredness and fatigue. Vitamin B6 additionally contributes to the regulation of hormonal activity. Those are the authorised claims; for a specific health concern, speak to a healthcare professional.

Is magnesium glycinate better than other forms?

Magnesium glycinate is magnesium bound to the amino acid glycine. It’s well tolerated and gentle on the stomach, whereas magnesium oxide is cheaper but less well absorbed and more likely to loosen the bowels. Check the elemental magnesium figure on the label rather than the larger compound weight.

What’s the difference between P5P and pyridoxine B6?

Pyridoxine is the standard supplemental form of vitamin B6; P5P (pyridoxal-5-phosphate) is the active form the body converts pyridoxine into. Products using P5P provide B6 in its body-ready form. Both count as vitamin B6, so both can carry the same authorised health claims when present in a significant amount.

How much magnesium and B6 should you take?

UK adults aged 19–64 need around 270–300 mg of magnesium daily and about 1.2–1.4 mg of vitamin B6, ideally from food. Supplements top this up. Don’t exceed the stated dose — high long-term B6 intakes can cause harm — and speak to your GP if you’re unsure what’s right for you.

Belle Balance is made by Evori, the publisher of this guide. Health claims for magnesium and vitamin B6 are quoted from the Great Britain Nutrition and Health Claims register. This article is educational and is not medical advice — food supplements should not replace a varied and balanced diet, and you should speak to your GP or pharmacist before starting or changing a supplement.