Big One is a daily vitamin crafted to support everyday vitality, filling nutrient gaps with proven essentials that fuel energy, immune resilience, and overall metabolic health. Key nutrients include B vitamins which help energy metabolism, plus vitamins A, C, D and E and minerals like magnesium and zinc to cover immunity and tissue health. Metabolic Maintenance has a family owned label for over four decades, known for purity and science based nutrition.

Available Sizes & Variants:

100 capsules - Daily multivitamin for foundational nutrition.

Benefits & Features:

• Daily energy support without the crash lasts, you know.
• Key nutrients work together to support immune function and everyday resilience, helping you stay active through busy days by providing steady micronutrient balance throughout your day.
• Supports energy metabolism and cognitive function through essential B vitamins and cofactors.
• Free from common fillers, gluten and dairy, aligning with clean label standards.
• Manufactured in cGMP facilities with strict third party testing and transparent quality controls, ensuring you get a pure, potent multivitamin every day without compromise, guaranteed.

Metabolic Maintenance has built a reputation over four decades as a family owned label known for purity and science based nutrition. This broad spectrum multivitamin is manufactured in cGMP facilities, with strict third party testing and transparent quality controls, and batches are produced every 90 days to guarantee freshness. The brand's products are free from gluten, dairy, artificial sweeteners, dyes and common contaminants, reinforcing its commitment to ethical sourcing and environmental stewardship. We also see customers benefiting from pairing this with magnesium glycinate, vitamin d supplement routines, or probiotics for a well rounded daily approach.

(other) Chelating agents include: glycine (synthetic), citric acid (corn fermentation), methionine (synthetic), glucuronic acid (synthetic). Cellulose for capsules is derived from softwood tree pulp.

• GTIN: 838287005209
• Manufacturer: Metabolic Maintenance
• Categories: CHECKOUT UPSELLIron (Ferritin) Tablets and SupplementsMetabolic MaintenanceNew ArrivalsTENAVitamins for Tiredness & Fatigue
• Best buy: 6 - 24 months+

United Kingdom Shipping:

Orders placed by 2pm (Monday to Friday) are dispatched the same day. Orders placed after 2pm will be dispatched the next working day.

Free shipping on orders over £50 to the UK.

Returns: Our products are meant to make you feel healthy and at your best. If you need to return your item, you can do so free of charge within 30 days in the same original and unopened packaging. Subject to T&C's.

Take one capsule daily with a meal, or as advised. Apply liberally to clean skin of torso\, legs\, and arms. Avoid sensitive areas and mucus membranes.

It is normal to experience a tingling sensation during initial use.

After application\, you may notice a slight salt-like mineral residue when the solution dries. This is normal.

Rinse or wipe off after 20 minutes\, if desired.

Please consult the product packaging for accurate instructions on how to use the product.

The Active Ingredient Is: Vitamin D3 (Cholecalciferol)

Vitamin D3, also known as cholecalciferol, is a fat-soluble vitamin that's essential for everyday bodily functioning and health upkeep. This form is commonly used in supplements to support your vitamin D status and related metabolic processes.

In multivitamin formulas, Vitamin D3 is provided in a bioavailable form to help support your body’s needs for bone health and immune support, among other roles noted in scientific resources. The product aims to deliver a broad base of nutrients in a bioavailable format to help overall metabolic health.

What Does Vitamin D3 Do?

Vitamin D3 helps regulate calcium metabolism, supporting normal bone mineralisation and immune function in line with EFSA guidance. It contributes to maintaining healthy teeth and skeletal health as part of a balanced diet.

EFSA notes that adequate Vitamin D3 status supports essential functions and overall health maintenance within the context of a varied diet and healthy lifestyle.

This supplement is not intended to diagnose, treat, cure, or prevent any disease.

Metabolic Maintenance has built a forty‑year track record as a family‑owned manufacturer known for science‑based formulations and a reputation for purity. This heritage, and a steady commitment to transparency, positions Metabolic Maintenance as a trusted partner in our portfolio. Their emphasis on rigorous quality and research‑driven development sets them apart in a crowded market, making them a natural fit for Welzo's standards of excellence. This brand was evaluated by our medical team for alignment with the standards we enforce, and the result is a partnership grounded in reliability and oversight.

Metabolic Maintenance manufactures with cGMP in mind and uses third‑party testing, reinforcing their commitment to quality. Their products are listed as free from preservatives, fillers, binders and artificial ingredients, with ethical sourcing and environmental stewardship highlighted as priorities. This combination of manufacturing discipline and third‑party verification underpins our confidence in choosing them over other brands in the market. For a deeper dive into testing and certifications, see the standards we enforce.

Product‑wise, The Big One (without Iron) is a broad‑spectrum multivitamin designed to support foundational micronutrient needs, with emphasis on bioavailable forms and a purity focus. This fits nicely with Metabolic Maintenance’s track record for purity and evidence‑based dosing strategies, making the brand particularly well suited to this supplement category and our customers’ expectations.