Best Vitamin D3 K2 Supplement UK 2026 | 5 Brands Compared

Last Updated: March 2026 | Written by Chris Jones | Social Media Manager at Nutrivity (7+ years in the UK supplement industry)

Vitamin D3 and K2 is one of the most popular supplement combinations in the UK — and for good reason. The NHS recommends everyone consider taking vitamin D, especially during autumn and winter. But with dozens of D3+K2 products flooding Amazon and the high street, it’s surprisingly difficult to know which one actually offers the best combination of strength, quality, and value.

After spending over seven years working in the UK supplement industry at Nutrivity, I’ve compared five of the most popular D3+K2 supplements available in the UK right now. This guide covers everything from dosage and ingredients to cost per day and dietary suitability. Full transparency — Nutrivity is one of the five brands included here, and it’s the company I work for. I’ve been honest about where competitors outperform us, because you deserve accurate information to make your own decision.

What to Look for in a Vitamin D3 + K2 Supplement

Not all D3+K2 supplements are the same. Before diving into the comparison, here’s what actually matters when choosing one.

Vitamin D3 Source: Lanolin vs Lichen

Most vitamin D3 supplements use cholecalciferol derived from lanolin, which is extracted from sheep’s wool. This makes the product vegetarian but not vegan. A smaller number of supplements use D3 sourced from lichen, a plant-based organism, making them fully vegan. Both forms are chemically identical and equally effective — the difference is purely about dietary suitability. If you follow a vegan or halal diet, always check whether the D3 is sourced from lanolin or lichen.

Vitamin K2 Form: MK-7 vs MK-4

Vitamin K2 comes in several forms, but MK-7 (menaquinone-7) is widely considered the most effective for supplementation. It has a longer half-life in the body than MK-4, meaning it remains active for longer and provides more sustained benefits. All five products in this comparison use the MK-7 form of K2.

Dosage

The NHS recommends everyone consider taking 10µg (400IU) of vitamin D daily as a minimum. However, many supplements provide 4000IU (100µg), which is the upper tolerable limit recommended by the European Food Safety Authority for adults. For vitamin K2, doses between 90–200µg per day are commonly used in supplements and research. A combined tablet offering 4000IU of D3 with 100µg of K2 is the most common high-strength formulation in the UK market.

Why Take D3 and K2 Together?

Vitamin D3 helps your body absorb calcium from food and supplements. Vitamin K2 then directs that calcium to your bones and teeth, rather than allowing it to accumulate in soft tissues like arteries. Without adequate K2, the calcium that D3 helps absorb may not be used as effectively. This is why combining both nutrients in a single supplement has become the preferred approach for many people focused on bone health and overall wellness.

The 5 Best Vitamin D3 + K2 Supplements in the UK — Compared

Here’s how five of the UK’s most popular D3+K2 supplements compare side by side.

Prices are approximate and based on the most commonly available pack at the time of writing. Prices may vary by retailer.

Individual Product Reviews

1. Nutrivity Vitamin D3 4000IU + K2 100µg Vegan Tablets

Best for: Vegan and halal diets, year-round supply, plant-based sourcing

The 365-tablet pouch provides a full year’s supply at one tablet per day. At approximately 4.1p per day, it sits in the mid-range for value — more expensive than Nutrition Geeks but significantly cheaper per day than Nature’s Best or Healthspan. The resealable pouch packaging reduces plastic waste compared to bottles.

Strengths: Only fully vegan D3+K2 in this comparison (lichen D3, natto K2), halal suitable with no animal-derived ingredients, full 12-month supply, UK manufactured to GMP standards, high strength 4000IU D3 with 100µg K2, free UK delivery, multiple pack sizes available.

Weaknesses: More expensive per day than Nutrition Geeks. Smaller brand with fewer customer reviews compared to Nutrition Geeks and Nutravita. Not oil-based (tablet format rather than oil-filled capsule). No BRC certification.

Best price: nutrivity.co.uk (free UK delivery)

2. Nutrition Geeks Vitamin D3 4000IU + K2 100µg Tablets

Best for: Budget-conscious buyers, massive social proof, year-round supply

Nutrition Geeks is the dominant player in the UK D3+K2 market on Amazon. With over 14,700 reviews and a 4.8-star rating, they have the strongest social proof of any product in this comparison by a significant margin. At £9.99 for a full year’s supply, they also offer the lowest cost per day at just 2.7p.

The tablets are formulated to be just 6mm in diameter, making them some of the smallest D3+K2 tablets available. The slim, letterbox-friendly packaging is a practical touch. However, the D3 is derived from lanolin rather than lichen, making this product vegetarian but not vegan or suitable for strict halal diets.

Strengths: Cheapest cost per day in this comparison (2.7p), massive review count (14,700+) providing exceptional social proof, full 12-month supply, very small tablets (6mm), letterbox-friendly packaging, UK made, strong net zero sustainability commitment.

Weaknesses: Not vegan (lanolin-derived D3), not specifically suitable for halal diets, no stated GMP or BRC certification visible on product listings, K2 source not specified. Relatively new brand compared to heritage names like Nature’s Best or Healthspan.

Best price: Amazon.co.uk or nutritiongeeks.co

3. Nutravita Vitamin D3 4000IU + K2 100µg Tablets

Best for: Established brand trust, premium K2 sourcing, multi-channel availability

Nutravita is one of the UK’s most recognised online supplement brands, and their D3+K2 formulation benefits from that established trust. The K2 in this product uses Kappa Bioscience’s K2VITAL, which is backed by over 20 clinical trials for effectiveness — a genuine quality differentiator that few competitors can match.

The 180-tablet pack provides a 6-month supply. At approximately 7.2p per day, it’s more expensive than both Nutrivity and Nutrition Geeks, but you’re paying for BRC certification (a higher auditing standard than standard GMP), a clinically validated K2 source, and wide retail availability across Amazon, Superdrug, and Sephora.

Strengths: Clinically validated K2VITAL from Kappa Bioscience (20+ trials), GMP and BRC certified, over 8,200 Amazon reviews, widely available across multiple retailers including Amazon, Superdrug and Sephora, established since 2014.

Weaknesses: Only 6-month supply (vs 12 months from Nutrivity and Nutrition Geeks), not vegan (lanolin-derived D3), higher cost per day than both year-supply competitors, no specific halal labelling, tablet format (not oil-based).

Best price: nutravita.co.uk

4. Nature’s Best Vitamin D3 1000IU + K2 90µg Capsules

Best for: Oil-based absorption, heritage brand expertise, lower maintenance dosing

Nature’s Best takes a different approach to most competitors. Their D3+K2 capsule provides a lower dose of vitamin D3 at 1000IU (25µg) with 90µg of K2, suspended in sunflower seed oil for improved absorption. Since both D3 and K2 are fat-soluble vitamins, an oil-based delivery system may offer a marginal absorption advantage.

Nature’s Best has decades of experience in the UK supplement market and their Technical Director was instrumental in bringing CoQ10 to the UK supplement industry. The K2 is sourced from chickpea protein rather than soya, which is relevant for those with soya allergies. However, the lower D3 strength means this isn’t ideal if you’ve been advised to take a higher dose, and at approximately 24.9p per day it is significantly more expensive.

Strengths: Oil-based capsule (potential absorption advantage for fat-soluble nutrients), decades of formulation expertise, K2 from chickpea protein (soya-free), UK manufactured to GMP standards, expert nutrition advisors available by phone, added rosemary extract and vitamin E for stability.

Weaknesses: Much lower D3 strength (1000IU vs 4000IU), lower K2 dose (90µg vs 100µg), only 60 capsules (2-month supply), significantly more expensive per day, not vegan (lanolin D3), not available on Amazon, not suitable during pregnancy or breastfeeding according to the manufacturer.

Best price: naturesbest.co.uk (free delivery over £20)

5. Healthspan Vitamin D3 + K2 Tablets

Best for: Medical advisory board credibility, brand trust, older adults

Healthspan is backed by a medical advisory board including Dr Hilary Jones, which gives it strong credibility particularly among older adults and those who value medical endorsement. Their D3+K2 product uses a max strength formulation of 100µg vitamin D3 (4000IU) combined with 100µg of vitamin K2 in MK-7 form.

The product is positioned as their premium bone and immune support option, with detailed educational content about the D3+K2 synergy on their website. Healthspan has over 130,000 five-star product reviews across their range. However, the 60-tablet pack provides only a 2-month supply, making it one of the more expensive options per day in this comparison.

Strengths: Medical advisory board lending strong professional credibility, well-established UK supplement brand with a loyal customer base, over 130,000 five-star reviews across their product range, strong educational content and customer support, subscribe-and-save option with price match promise.

Weaknesses: Only 60 tablets (2-month supply), expensive per day compared to year-supply options, not vegan (lanolin-derived D3), no specific halal labelling, limited availability (mostly direct from Healthspan), subscription model may not suit all buyers.

Best price: healthspan.co.uk (subscribe and save available)

Which Vitamin D3 + K2 Supplement Should You Buy?

The right choice depends on your priorities:

If you follow a vegan or halal diet — Nutrivity is the only product in this comparison that uses plant-based lichen D3 and natto-derived K2, making it fully vegan and suitable for halal diets with no animal-derived ingredients. Most other D3+K2 supplements use lanolin, which is derived from sheep’s wool.

If you want the lowest possible cost — Nutrition Geeks at 2.7p per day is hard to beat. A full year’s supply for under £10 with over 14,700 reviews makes it the clear budget winner.

If you want clinically validated K2 sourcing — Nutravita’s use of Kappa Bioscience K2VITAL, backed by 20+ clinical trials, gives it the strongest ingredient sourcing credentials. Their BRC certification is also a higher quality standard than basic GMP.

If absorption is your top priority — Nature’s Best is the only oil-based option here. Since both D3 and K2 are fat-soluble, the sunflower oil suspension may provide a slight absorption advantage. However, you pay significantly more per day and get a much lower D3 dose.

If medical credibility matters to you — Healthspan’s medical advisory board, including Dr Hilary Jones, provides reassurance for those who value professional endorsement. Their subscribe-and-save model also suits people who want automatic reordering.

If you want a full year’s supply with no animal ingredients — Nutrivity is the only product that combines a 365-tablet year’s supply with fully vegan, halal-suitable sourcing at a competitive price point.

Value Breakdown: Annual Cost Comparison

Since many people take D3+K2 year-round, here’s what each option actually costs over 12 months at the standard recommended dose of one tablet per day:

This comparison highlights a significant cost difference over the course of a year. Choosing a 12-month supply upfront can save considerable money versus buying smaller packs repeatedly. The difference between the cheapest annual option (Nutrition Geeks at £9.99) and the most expensive (Healthspan at approximately £95.70) is over £85 per year for what is essentially the same daily dose of D3 and K2.

Our Methodology

This comparison was created by Chris Jones, Social Media Manager at Nutrivity with over seven years of experience in the UK supplement industry. Products were evaluated based on publicly available information including strength, ingredients, manufacturing standards, pricing, dietary suitability, and customer reviews.

In the interest of transparency: Nutrivity is included as one of the five products reviewed. We have made every effort to present competitor products fairly, including acknowledging their strengths and areas where they outperform Nutrivity — such as Nutrition Geeks’ lower price point and Nutravita’s clinically validated K2 sourcing. Pricing information was gathered in March 2026 and may have changed since publication.

This article provides general information about vitamin D3 and K2 supplements. It is not medical advice. These are food supplements and are not intended to diagnose, treat, cure, or prevent any disease. Always consult a healthcare professional before starting any new supplement, particularly if you have an existing medical condition, take prescribed medication (especially anticoagulants), or are pregnant or breastfeeding.

Frequently Asked Questions