THE ALPHA01 GUIDE VITAMINS & DAILY WELLBEING
Vitamin D3 & K2 Supplement: What 4000 IU Means for a UK Winter
Drops, softgels or vegan capsules?
A clearer look at the two vitamins and the numbers on the label.
As the days shorten for another UK winter, have you found yourself wondering about vitamin D? The NHS confirms that “between October and early March we do not make enough vitamin D from sunlight,” which is why it advises that everyone should consider a daily supplement during these darker months 2. This is a key nutrient that contributes to the normal function of the immune system, to the maintenance of normal bones and to the maintenance of normal muscle function 1. Yet when you look for a supplement, you are met with a confusing choice, particularly when a label reads 4000 IU. This guide explains what that number means and why vitamin D3 is so often paired with vitamin K2.
Recognising the need for a supplement is only half the story; choosing one is where the real questions begin. Our drops give 4000 IU, or 100 micrograms, of vitamin D3 with 25µg of vitamin K2 in one 0.25ml serving, at about 7p a day 5. Below, they sit side by side with our softgels and vegan capsules, so you can pick the one that fits your winter.
Vitamin D3 and K2 drops at a glance
- Who they suit: adults who want vitamin D3 through the darker months, with vitamin K2 in the same single serving, and would rather not swallow a capsule.
- One daily serving (0.25ml) gives: 100µg (4,000 IU) of vitamin D3 and 25µg of vitamin K2 as MK-7 5.
- How to take it: one 0.25ml serving a day, measured with the dropper 5.
- Price: £8.99 for 120 days, about 7p a day.
- What the two vitamins do: vitamin D contributes to the normal function of the immune system and to the maintenance of normal teeth, and vitamin K contributes to the maintenance of normal bones 1.
VITAMIN D3 + K2 4000 IU · 30ML DROPS
£8.99 · 120 servings · 0.25ml a day · 100µg (4,000 IU) vitamin D3 · 25µg vitamin K2 MK-7 · MCT coconut oil carrier
Explore the drops01 / FIND YOUR FORMAT
Which vitamin D3 supplement is right for you: drops, softgels or vegan capsules?
Three of our products give the same 100µg of vitamin D3 a day, so between them the choice isn’t about the dose. It’s about the details: whether you want K2 included, what the D3 is made from, and how you like to take it.
D3 + K2 drops
0.25ml per serving
100µg D3 + 25µg K2
120 servings in 30ml
D3 softgels
1 softgel per serving
100µg D3 · no K2
180 servings per pack
Organic D3 capsules
1 capsule per serving
100µg D3 from lichen
60 servings per pack
Vitamin D3 and K2 drops: two vitamins, one measured dose
Does one more capsule to swallow feel like a chore? Our Vitamin D3 + K2 drops are a 0.25ml dose, measured with the dropper in the cap.
They’re the only product in our range with D3 and K2 together, and a bottle lasts 120 days for £8.99, about 7p a day. The D3 comes from lanolin, found in sheep’s wool.
Vitamin D3 softgels: the lowest price per day
Watching the pennies? The Vitamin D3 4000 IU softgels give the same 100µg in coconut oil, with no K2.
A pouch of 180 lasts six months for £5.99, about 3p a day, in a bovine gelatin shell.
Vegan vitamin D3: from lichen, certified organic
Need a vegan vitamin D3? The Organic Vitamin D3 4000 IU capsules use D3 from lichen in a plant-derived shell.
It’s 60 capsules for £8.99, about 15p a day, from our vegan range. You can add K2 separately with our vegan K2 MK-7 capsules.
A lower dose of vitamin D3
Prefer a smaller daily amount? Our Vitamin D3 1000 IU drops give 25µg in a single drop, with 600 drops in a bottle for £6.99, about 1p a day. Our Calcium and Vitamin D3 gummies give the same 25µg with 500mg of calcium in two gummies 5.
The drops sit in our Vitamins range; vitamin D from a food source is covered in our cod liver oil guide, and calcium itself in our calcium guide.
02 / THE UK WINTER QUESTION
How much vitamin D do I need? What the NHS says
You’ve probably heard a few different figures, so let’s start with the official one. The NHS advises everyone to consider 10 micrograms of vitamin D a day during the autumn and winter, which is 400 IU 2. People who are rarely outdoors, who cover most of their skin, or who have dark skin are advised to consider it all year round 2.
Vitamin D in a multivitamin, cod liver oil or calcium: choose one source
Already taking a product with vitamin D in it? Our multivitamins give 5µg, our cod liver oil 5µg, our Calcium Magnesium Zinc tablets 2.5µg and our ashwagandha gummies 25µg a serving 5. The drops already give 100µg in one serving, so let them be your one vitamin D product, or keep your current one and pair it with the 1000 IU drops or the calcium gummies above.
03 / READ THE LABEL
Vitamin D3 4000 IU on the label: IU, micrograms and %NRV explained
IU, µg and %NRV: what does it all mean? It’s simpler than it looks, because all three describe the same dose. IU stands for International Units, and the NHS gives the conversion: “1 microgram of vitamin D is equal to 40 IU.” 2
reference value
Vitamin D3 + K2 4000 IU drops, nutrition panel 5
Two vitamins in one measured serving
0.25ml- Vitamin D3
- 100 µg4,000 IU · 2,000% NRV
- Vitamin K2 MK-7
- 25 µg33% NRV
- Bottle volume
- 30 ml
- Labelled servings
- 120
- Carrier
- MCT oilFrom coconut
The third number, %NRV, compares the dose with the Nutrient Reference Value, the daily reference figure UK labels use. For vitamin D that figure is 5µg, which is why 100µg reads as 2,000%.
Besides the two vitamins, the only other ingredient is MCT oil from coconut 5. It’s the carrier liquid, so a 0.25ml dose can be measured with the dropper. Both the box and the bottle carry 3rd Party Tested and GMP Certified marks.
04 / COMPARE YOUR OPTIONS
Vitamin D3 and K2 drops vs softgels vs vegan capsules: how they compare
The table puts four of our labels side by side: what each one contains, and who it suits. Prices are correct at the time of writing.
| Product | What the label declares | Choose your routine |
|---|---|---|
0.25ml · vitamin D3 100µg (4,000 IU), 2,000% NRV · vitamin K2 MK-7 25µg, 33% NRV · MCT coconut oil carrier | Choose if you want D3 and K2 in one measured dose and no capsule to swallow · D3 from lanolin (sheep’s wool) · 120 days · £8.99: about 7p a day | |
1 softgel · vitamin D3 100µg (4,000 IU), 2,000% NRV · no K2 · coconut oil in a bovine gelatin shell | Choose if you want the lowest price per day and six months in one pouch · £5.99: about 3p a day | |
1 capsule · vitamin D3 from lichen 100µg (4,000 IU), 2,000% NRV · no K2 · organic brown rice flour in a hypromellose shell | Choose if you follow a vegan diet or want certified organic · 60 days · £8.99: about 15p a day | |
1 capsule · vitamin K2 MK-7 300µg, 400% NRV · no D3 · MK-7 from natto, 1mg BioPerine, hypromellose shell | Choose if you want K2 on its own · vegan · £7.99: about 7p a day |
Each is one serving a day, so choose by whether you want K2 included, what the D3 comes from and the price per day.
D3 + K2 · ONE MEASURED DOSE
Vitamin D3 + K2 4000 IU
100µg (4,000 IU) D3 + 25µg K2 MK-7.
One 0.25ml serving, measured with the dropper.
VITAMIN D3 · COCONUT OIL
Vitamin D3 4000 IU
100µg (4,000 IU) vitamin D3 per softgel.
Coconut oil in a bovine gelatin shell.
D3 FROM LICHEN · CERTIFIED ORGANIC
Organic Vitamin D3 4000 IU
100µg (4,000 IU) vitamin D3 per capsule.
Organic brown rice flour and a plant-derived shell.
VITAMIN K2 · ON ITS OWN
Vegan Vitamin K2 MK-7 300µg
300µg vitamin K2 MK-7 per capsule.
From natto, with 1mg BioPerine and no D3.
05 / TWO VITAMINS, ONE BOTTLE
What are vitamin D3 and K2, and why are they in the same bottle?
On our ingredients list you’ll see the name cholecalciferol: that’s vitamin D3. Vitamin D is what the body creates from direct sunlight on the skin 2. Food provides some too, in oily fish, red meat, egg yolks and fortified foods, though the NHS notes it’s difficult to get enough from food alone 2.
Vitamin K is a group of vitamins the body needs for blood clotting 3. The K2 in our drops is MK-7, menaquinone-7, the form found in natto, the Japanese fermented soy food 4.
Why put them together? Vitamin D and vitamin K both contribute to the maintenance of normal bones, so one measured dose gives you the two together 1.
Want K2 on its own? Our vegan K2 MK-7 capsules come in 100µg, 300µg and 600µg a capsule, against 25µg in a serving of the drops 5.
Vitamin D3
Cholecalciferol
Vitamin K2
Menaquinone-7 / MK-7
Measured dose
0.25ml with the dropper
Two amounts
100µg D3 + 25µg K2
06 / UNDERSTAND THE CLAIMS
Vitamin D3 K2 Benefits
Every health claim on the Great Britain register passed a scientific review: independent scientists examined the research and the evidence behind it before it was authorised 1. The law itself says that health claims shall be “based on and substantiated by generally accepted scientific evidence” 6.
The benefits we can state come from the two vitamins, each authorised on the Great Britain Nutrition and Health Claims Register 1. A claim needs at least 15% of the NRV in a daily serving, and our drops give 2,000% for vitamin D and 33% for vitamin K.
Here they are, word for word 1:
Vitamin D
- Vitamin D contributes to the maintenance of normal bones.
- Vitamin D contributes to the maintenance of normal teeth.
- Vitamin D contributes to the maintenance of normal muscle function.
- Vitamin D contributes to the normal function of the immune system.
- Vitamin D contributes to normal absorption/utilisation of calcium and phosphorus. Vitamin D contributes to normal blood calcium levels.
- Vitamin D has a role in the process of cell division.
Vitamin K
Both vitamins meet the condition in a single 0.25ml serving, so every statement above applies to the drops in full.
07 / KEEP IT SIMPLE
How to take vitamin D3 and K2 drops
One measured serving a day
The easiest way to fail at a new habit is to make it complicated, and this one is simple: the label says 0.25ml per day, and the dropper measures it. It names no time of day and no food instruction, so pick a moment you won’t forget and make it part of your daily wellbeing routine. Store the bottle in a cool, dry place out of direct sunlight, out of reach of young children, and don’t use it if the safety seal is missing or damaged.
Ready for the dark months?
Want D3 and K2 without another capsule to swallow? The drops keep it simple: one measured 0.25ml dose a day, D3 and K2 together, about four months to a bottle at about 7p a day.
Shop vitamin D3 + K2 drops08 / A LITTLE MORE CLARITY
Vitamin D3 and K2 FAQs
What are the benefits of vitamin D3 and K2?
Vitamin D contributes to the normal function of the immune system, to the maintenance of normal bones and teeth and to the maintenance of normal muscle function, and vitamin K contributes to normal blood clotting 1. All nine statements are listed word for word above.
How many IU are in a microgram of vitamin D3?
Forty. So the NHS figure of 10 micrograms is 400 IU, and the 100 micrograms in our drops is 4,000 IU 2.
Is 4,000 IU of vitamin D a day too much?
Should I take vitamin D3 all year round?
The NHS advice to consider a daily supplement covers autumn and winter, because from about late March to the end of September most people can make the vitamin D they need from sunlight 2. If you are rarely outdoors, cover most of your skin or have dark skin, the NHS advises considering one all year round 2.
Are vitamin D3 and K2 drops vegan?
The D3 in our drops is made from lanolin, which comes from sheep’s wool. For a vegan routine, pair the organic lichen D3 capsules with our vegan K2 MK-7 capsules.
Can children take vitamin D3 4000 IU drops?
No, the label says the drops are not intended for children 5.
What time of day should I take vitamin D3 and K2?
The label names no time of day, so any time you’ll remember works. What matters more is the amount: one 0.25ml serving, once a day.
Can I take vitamin D3 and K2 with blood thinners?
Speak to your doctor first. Research on MK-7 found that 50µg a day or more may interfere with blood thinner treatment, and although our drops supply 25µg, that decision belongs with your doctor 4.
YOUR ROUTINE, YOUR CHOICE
So, which vitamin D3 for this winter?
If you want D3 and K2 in one measured dose, choose the Vitamin D3 + K2 drops. If price matters most, the softgels are about 3p a day, and if you’re vegan, the organic lichen capsules are yours. Whichever you pick, one serving a day gives you 100µg of vitamin D, which contributes to the normal function of the immune system and to the maintenance of normal bones 1.
GO TO THE SOURCE
Sources & references
Checked against the product labels and the GB Nutrition and Health Claims Register, September 2026.
- Department of Health and Social Care. Great Britain nutrition and health claims (NHC) register, GOV.UK (vitamin D and vitamin K entries, authorised). Accessed 2026-09-25. View source
- Vitamin D – NHS. Accessed 2026-09-18. View source
- Vitamin K – NHS. Accessed 2026-09-18. View source
- Schurgers LJ, Teunissen KJ, Hamulyák K, Knapen MH, Vik H, Vermeer C. (2007). Vitamin K-containing dietary supplements: comparison of synthetic vitamin K1 and natto-derived menaquinone-7. Blood, 109(8):3279-3283 (cited for what MK-7 is and the anticoagulant note only). PubMed. View source
- Alpha01. Vitamin D3+K2 4000 IU, 30ml Tincture: nutrition information panel, ingredients, suggested use, storage, caution and price; Vitamin D3 4000iu Softgels, Organic Vitamin D3 4000IU Capsules, Vitamin D3 1000 IU drops, Vegan Vitamin K2 MK-7 (100µg, 300µg, 600µg), Calcium and Vitamin D3 gummies, Cod Liver Oil, Calcium Magnesium Zinc, MultiVitamin and Minerals, Women’s Multivitamins and Ashwagandha gummies labels and prices. Accessed 2026-09-25. View source
- Regulation (EC) No 1924/2006 on nutrition and health claims made on foods, Article 6: scientific substantiation for claims, as it applies in Great Britain. legislation.gov.uk. Accessed 2026-09-25. View source
