Can I take Magnesium and Vitamin B complex together?

Why this happens

Magnesium and B vitamins (especially Vitamin B6) have a synergistic relationship. Vitamin B6 helps the body absorb magnesium more efficiently into the cells where it is needed. They do not compete for absorption or interfere with how the other is processed by the liver or kidneys.

What you should do

It is safe to take these together. For the best absorption, you can take them with a meal. Always stick to the recommended daily dose on the packaging, as taking very high doses of magnesium can sometimes cause diarrhoea or stomach upset.

Important precautions

Kidney disease

If you have severe kidney problems, your body may not be able to remove excess magnesium, leading to dangerously high levels in the blood. Check with your doctor before use.

Long-term high-dose use

Taking high doses of Vitamin B6 (usually over 10mg to 50mg daily depending on the product) for a long time can cause peripheral neuropathy, which is tingling, numbness, or pain in the hands and feet.

Food and drink warnings

Alcohol

It is best to avoid or strictly limit alcohol when taking Vitamin B complex. Alcohol interferes with the absorption of B vitamins (especially B1 and B12) and increases their excretion from the body, making the supplement less effective. Additionally, chronic alcohol use can lead to severe B vitamin deficiencies.

It is best to avoid or strictly limit alcohol when taking magnesium. Alcohol acts as a diuretic, which can increase the amount of magnesium your body loses through urine, potentially making the supplement less effective. Additionally, chronic alcohol use can lead to magnesium deficiency.

Dairy products (Milk, Cheese, Yoghurt)

Avoid taking magnesium supplements at the same time as large amounts of dairy products. Dairy is high in calcium, and high doses of calcium can compete with magnesium for absorption in the gut, meaning you may not get the full benefit of your supplement. It is best to space them at least 2 hours apart.

Caffeine (Coffee, Tea, Energy drinks)

It is best to limit caffeine intake around the time you take magnesium. Like alcohol, caffeine has a mild diuretic effect and can increase the excretion of magnesium through the kidneys.

Caffeine can act as a mild diuretic and may interfere with the absorption of certain B vitamins if consumed in large quantities at the same time as your supplement. Consider taking your B complex with water rather than a large cup of coffee.

Using other medicines

Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.

Disclaimer

This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.