The B vitamins are a group of 8 water-soluble nutrients involved in energy metabolism, nervous system function, neurotransmitter synthesis, red blood cell formation and homocysteine metabolism. Unlike fat-soluble vitamins, they are not stored in significant amounts, so they need a regular daily supply. Modern diets, food refining and lifestyle factors (pregnancy, intense exercise, stress) can all increase the need for a quality B-complex.

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What sets this formula apart is its systematic use of biologically active forms — the forms the body can use directly, without needing further enzymatic conversion. Quatrefolic is the most advanced folate form available, the glucosamine salt of 5-MTHF, particularly relevant for people with MTHFR gene variants that reduce the conversion of synthetic folic acid. Methylcobalamin is the active form of B12, used directly by the body, unlike cyanocobalamin which requires conversion. P-5-P is the active coenzyme form of B6, with higher bioavailability than standard pyridoxine.

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Thiamine (B1) supports carbohydrate metabolism and normal nervous system function. Riboflavin (B2) contributes to normal energy metabolism and cellular antioxidant protection. Niacin (B3) contributes to the reduction of tiredness and fatigue and supports the nervous system. Vitamin B6 is involved in over 100 enzymatic reactions, including amino acid metabolism and neurotransmitter synthesis. Folate is essential for DNA synthesis, cell division and homocysteine metabolism. Vitamin B12 supports red blood cell formation, the nervous system and energy metabolism. Biotin contributes to normal hair, skin and mucous membranes. Pantothenic acid (B5) contributes to normal mental performance and normal energy metabolism.

Take 1 capsule per day with a meal, ideally in the morning. The bottle of 60 capsules covers a 2-month course.

Food supplement. Not a substitute for a varied, balanced diet and a healthy lifestyle. Do not exceed the recommended daily dose. People on medical treatment, particularly anti-epileptic medication or methotrexate, should consult a healthcare professional before use. Pregnant or breastfeeding women should also seek medical advice. Store at room temperature, away from heat and humidity. Keep out of reach of young children.

Is this B Complex suitable for people with an MTHFR variant?

Yes — this is one of the formula’s key advantages. It contains Quatrefolic (5-MTHF), the directly active form of folate, which does not require conversion by the MTHFR enzyme, unlike supplements containing synthetic folic acid.

Can I take the B Complex with other supplements?

Yes, it fits well into a broader supplementation routine alongside magnesium, zinc, omega-3s or vitamin D. We recommend not combining it with another multivitamin already containing B vitamins, to avoid excess intake.

Where can I buy the Fully Active B Complex in Paris?

Fully Active B Complex Quatrefolic 60 capsules by Doctor’s Best is available at Herba Barona, 10 rue Théophile Roussel, Paris 12, in store or online with delivery across France and Europe.

Herba Barona is an independent specialist supplement shop in the heart of Paris — established in 2006. What you order is genuinely on our shelves: we ship from our own stock, with no dropshipping and no long waits.

Visit us at 10 rue Théophile Roussel, Paris 12 — or use Click & Collect and pick up your order in-store. We also deliver across France and Europe. Friendly, expert advice in English from our team.

Where is the shop?

Herba Barona is at 10 rue Théophile Roussel, 75012 Paris — a two-minute walk from Ledru-Rollin (line 8), close to Bastille. Open Tuesday to Saturday, 9:30 am–6:30 pm.

Can I order online or collect in store?

Yes. We ship across France and Europe under the same conditions as our French store, or choose Click & Collect to pick up your order for free at our Paris shop.