Best Vitamin D3 + K2 Supplements UK 2026: Eight Products Scored on the Evidence

Each product is scored 0 to 10 on every criterion. The weighted total out of 100 sets the ranking. Weights were fixed before scoring and are the same for every product. Most of the weight (90%) is on ingredient quality, dose, testing and labelling; price per daily serving carries 10%. Anything a page does not disclose scores 0 for that item: we never assume an ingredient or a test we cannot see. Each product also shows a relative score (best product in this guide = 100): its weighted total divided by the top product's weighted total, multiplied by 100 (see how relative scores work). Evidence was checked on 1 November 2026. Full method.

Vitamin D3 (cholecalciferol) is the form of vitamin D used in all eight products. Vitamin K2 is a group of compounds called menaquinones; all eight products use menaquinone-7 (MK-7). The two vitamins are separate nutrients with separate authorised claims. There is no authorised claim for the combination.

Speak to your GP or pharmacist before taking supplements if you are pregnant or breastfeeding, taking medication or being treated for a medical condition. Several products here are labelled for adults only or for ages 13 or 14 and over.

Products appear in order of their weighted score from the scoring table. We read each product page, and any testing documents linked from it, on 1 November 2026. Amazon prices are the listed price on that date. We have not bought or tested these products ourselves.

We compared eight combined vitamin D3 and K2 supplements on sale to UK buyers, using each product page and any testing documents linked from it, re-read on 1 November 2026. For Nutrition Geeks and EVO Nutrition, which we link to on Amazon UK, we also read the brand's own product page. Each product was scored 0 to 10 on eight criteria, weighted mainly on ingredient quality. The weights and point rules were fixed before scoring and are identical for every product. If a page does not disclose something, that item scores 0: we never assume an ingredient, a source or a test we cannot see. Where a brand states its product contains no fillers and its ingredient list shows none, we take the list as stated.

• D3 form and source (15%). Cholecalciferol (D3) named (4 points); D3 source stated, such as lanolin or lichen (4); product or D3 stated as vegan (2).
• K2 form (15%). K2 named as menaquinone-7 (MK-7) (4); MK-7 isomer stated, such as all-trans (3); branded or standardised K2 ingredient named, such as K2VITAL® or MenaQ7® (3).
• Dose: level and transparency (10%). D3 at or below 100 micrograms (4,000 IU) at the highest directed daily dose, by every figure on the page (3); no conflicting dose figures (2); D3 given in micrograms (1); %NRV given for both vitamins (2); K2 at least 15% of the NRV per serving (2).
• Fillers, excipients and additives (20%). Starts at 10. We deduct 2 points for each bulking or base agent (such as microcrystalline cellulose, dicalcium phosphate, plant cellulose or alfalfa base), anti-caking or flow agent (magnesium stearate, silicon dioxide), sweetener, preservative or colour; and 1 point for each emulsifier, acidity regulator, flavouring, antioxidant or encapsulating aid. The capsule shell, a carrier oil, water in a liquid and the vitamins themselves are not deducted. Minimum 0.
• Carrier oil and food guidance (10%). Vitamins D and K are fat-soluble. A fat-based carrier in the formula, such as MCT or coconut oil (8); the page advises taking it with food (2).
• Testing and certificates (10%). A certificate of analysis for this product published and read by us (6); accredited laboratory named on it (2); batch matched to stock on sale (2). Without a readable certificate, a public batch-report lookup on the product page scores 1. Statements such as "third-party tested" score 0.
• Label and safety warnings (10%). Complete ingredient list using ingredient names (2, or 1 if partial); additive functions named, or no additives present (1); a specific anticoagulant or blood-thinner warning (3); a general caution for pregnancy, medication or medical conditions (1); an age or do-not-exceed statement (1); allergen information (2). A statement playing down medication interactions loses 2 points.
• Price per daily serving (10%). 10 × (lowest price per daily serving ÷ this product's price per daily serving). Price is based on each brand's 3-pack price divided by 3 to give a single-pack price, then per daily serving; where no 3-pack is sold we use the single-pack price. We use one-off prices from each brand's own product page, not subscriptions, excluding delivery. One serving is the smallest directed daily amount, so doses differ between products.

Relative scores (best product in this guide = 100). A product's relative score is its weighted total divided by the weighted total of the best product in this guide, multiplied by 100 and rounded to one decimal place. It shows how each product compares with the best one we assessed. It is not a percentage of our criteria met: the best product, Together Health Vitamin D3 and Vitamin K2, scored 68.6/100 on our absolute criteria. The same calculation is applied to every product, so it does not change the order. Each product's absolute score out of 100 (its weighted total) is shown next to its relative score and in the scoring table.

We considered other UK brands. We could not find a combined D3 and K2 product from Vitabiotics or Wild Nutrition when we checked, so they are not included. The ranking is an editorial judgement based on those scores. It is not a clinical comparison, an independent certification or a laboratory test, and we did not buy or test any product. Every product is scored the same way. Commission is explained in the note at the top of this page.