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Vitamin D3 Supplements

Support immunity, mood, bones and overall wellbeing with high‑quality Vitamin D3. This collection brings together our most effective D3 formulas, from daily capsules to high‑strength drops, designed to help you maintain optimal levels all year round.

33 Product Results

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Vitamin D3 + K2 - 60 Capsules | Seeking Health

Seeking Health

Vitamin D3 + K2 - 60 Capsules

£25.49

Vitamin D3 + K2 Drops - 30ml | Seeking Health

Seeking Health

Vitamin D3 + K2 Drops - 30ml

£31.49

Vitamin D3 with K2 - 30ml | Metagenics

Metagenics

Vitamin D3 with K2 - 30ml

£23.99

Vitamin D3 Drops - 30ml | Seeking Health

Seeking Health

Vitamin D3 Drops - 30ml

£27.49

Vitamin D3 5,000 IU - 60 Capsules | Pure Encapsulations

Pure Encapsulations

Vitamin D3 5,000 IU - 60 Capsules

£23.40

Vitamin D3/K2 Topical Patch - 30 Patches | PatchMD

PatchMD

Vitamin D3/K2 Topical Patch - 30 Patches

£19.50

Vitamin D3/K2 Liquid - 30ml | Amy Myers MD

Amy Myers MD

Vitamin D3/K2 Liquid - 30ml

£35.99

D3K2 - 50ml | Quicksilver Scientific

Quicksilver Scientific

D3K2 - 50ml

£50.50

Vitamin D3 Drops - 30ml | Metagenics

Metagenics

Vitamin D3 Drops - 30ml

£17.99

Vitamin D3 5,000 IU - 120 Capsules | Pure Encapsulations

Pure Encapsulations

Vitamin D3 5,000 IU - 120 Capsules

£39.50

Vitamin D3 1,000 IU - 120 Capsules | Pure Encapsulations

Pure Encapsulations

Vitamin D3 1,000 IU - 120 Capsules

£29.70

Vitamin D3 10,000 IU - 60 Capsules | Vital Nutrients

Vital Nutrients

Vitamin D3 10,000 IU - 60 Capsules

£30.99

Vitamin D3/K2 10,000 IU - 30 Capsules | Amy Myers MD

Amy Myers MD

Vitamin D3/K2 10,000 IU - 30 Capsules

£22.49

Vitamin D3/K2 Emulsion - 30ml | Nutra Biogenesis

Nutra Biogenesis

Vitamin D3/K2 Emulsion - 30ml

£29.99

Vitamin D3 & K2 - 60 Capsules | Cytoplan

Cytoplan

Vitamin D3 & K2 - 60 Capsules

£23.49

Vitamin D3 25mcg (1,000 IU) - 90 Softgels | Life Extension

Life Extension

Vitamin D3 25mcg (1,000 IU) - 90 Softgels

£7.49

What Is Vitamin D3?

Vitamin D3 (cholecalciferol) is the biologically active form of vitamin D your body naturally produces when sunlight hits your skin. It’s the most effective and most bioavailable form of vitamin D for raising and maintaining healthy blood levels.

Vitamin D3 plays a key role in:

  • Immune defence
  • Bone strength & calcium absorption
  • Mood balance
  • Muscle function
  • Hormone regulation

Is Vitamin D3 the Same as Vitamin D?

Vitamin D is the umbrella term for all forms of the nutrient. Vitamin D3 is the specific form your body prefers.

There are two main supplemental forms:

  • Vitamin D2 — plant‑derived, less effective
  • Vitamin D3 — animal‑derived or vegan‑friendly lichen‑derived, more potent and longer‑lasting

When people say 'vitamin D', they almost always mean D3, because it’s the form used in most supplements and recommended by health professionals.

How Much Vitamin D3 Should I Take Daily?

Your ideal dose depends on lifestyle, sunlight exposure and individual needs, but our in-house practitioner, Josephine Smith, recommends:

  • Adults: 1,000–2,000 IU daily
  • Low sunlight exposure (UK winter, indoor lifestyle): 2,000–4,000 IU daily
  • Those with deficiency: Higher doses may be recommended by a clinician

Vitamin D3 levels naturally decline with age, making supplementation in the over 50s increasingly important. Vitamin D3 supplements are often recommended as a supplement for men over 50 as they support testosterone regulation, bone strength and immune function. Equally, it is often recommended to women over 50, as it calcium absorption and helps counter natural bone‑density decline.

Why Vitamin D3 Matters Year‑Round

Even in summer, many people in the UK struggle to maintain optimal levels due to:

  • Indoor working patterns
  • Sunscreen use
  • Low UVB strength
  • Cloudy weather
  • Skin tone differences affecting synthesis

Consistent supplementation helps keep levels stable and supports immunity, mood and bone health throughout the year. You can read more about the importance of Vitamin D in the Summer here.

Why is Vitamin D3 Paired With Vitamin K2?

Vitamin D3 increases how much calcium you absorb from food and supplements. Vitamin K2 decides where that calcium goes.

  • Vitamin D3 boosts calcium absorption  
    D3 increases intestinal absorption of calcium, raising levels in the bloodstream.
  • Vitamin K2 directs calcium to the right places  
    K2 activates proteins (like osteocalcin and MGP) that escort calcium into bones and teeth, and keep it out of arteries and soft tissues.

Together this means:

  • Stronger bones
  • Better calcium utilisation
  • Lower risk of calcium depositing in arteries
  • More complete support for long‑term cardiovascular health

The Bone Health Benefit

D3 alone helps you absorb calcium. K2 ensures that calcium is built into bone, improving density and structure.

This is why many practitioners prefer D3 + K2 formulas for people concerned about bone strength, ageing, menopause, or low dietary calcium.