D3 + K2: How Much You Really Need

One tub says 5,000 IU, the next says 1,000. Which amount is right is not told by the number on the pack but by your blood level. Have your 25-OH-D measured, set the dose by it and break every label down to a day: dose divided by rhythm. Here you get the calculation, the research on higher daily amounts in plain language and the plan for how our depot puts it into practice.

What D3 and K2 are in brief

Vitamin D3 (cholecalciferol) is the form your skin makes itself in sunlight, and the form in every good supplement. Vitamin K2 belongs to the menaquinone family. The variant that matters is MK-7. Both are fat-soluble. That is not a detail for chemists, it is the reason you take them with a meal that contains fat and why your body can store vitamin D for days.

What the two do in the body is clearly named. Vitamin D contributes to the normal absorption/utilisation of calcium and phosphorus. Vitamin D contributes to the maintenance of normal bones. Vitamin K contributes to the maintenance of normal bones. Vitamin K contributes to normal blood clotting.

Why the two belong in the same tablet

What links them is bone. Vitamin D opens the door for calcium: it makes sure the calcium from your food is absorbed and used at all. Vitamin K contributes to the maintenance of normal bones. Two nutrients, one topic, which is why they sit together in one tablet in so many supplements.

The combination needs no more justification than that. Both vitamins make sense on their own, and there is no reason to separate them. Why the combination came about in the first place is in the linked guide further down. Here it is about the numbers.

Who is this interesting for?

The dose question is not equally urgent for everyone. It matters most if you recognise yourself here:

• You supplement from October to March. In the dark months the sun stands too low in this part of the world, and your skin makes hardly any vitamin D. That is exactly why most people reach for the tub in winter.
• You work indoors. Office, shifts, home office: if you see most of your daylight through a window pane, you rarely reach much self-production even in summer.
• You have a high-dose tub in the cupboard. 5,000 or 10,000 IU per piece, and nobody told you in which rhythm it is meant to be taken. The next section is a must for you. Our Vitamin D3 Depot is built for exactly this case.
• You take several supplements. Vitamin D is often in the multivitamin too. If you take both, you add up and mostly do not do the maths.
• You keep an eye on your bones. Supply matters more over the years, and bone is exactly where D3 and K2 work together.

Intake & dosage: blood level first, then the calculation

Our order: measure, dose, measure again after a few months. At the doctor or in a lab you have 25-OH-D determined, which is how vitamin D circulates in the blood. The result tells you where to start. The second measurement shows whether your amount fits. The blood level needs weeks to settle, so do not recheck after two.

Two pieces of research show why there is no one-size number. Healthy men were given 25, 125 or 250 µg of vitamin D3 daily for 20 weeks in winter, which is 1,000, 5,000 and 10,000 IU. The blood level rose in direct proportion to the amount. The authors conclude that healthy men use roughly 3,000 to 5,000 IU a day and cover most of it in winter from the stores built up in summer. An analysis of healthy adults who took self-chosen amounts of up to well over 10,000 IU a day found two patterns: the blood level rises steepest at small amounts and flattens at large ones. And people who weigh more need clearly more for the same level. The authors saw no sign of raised blood calcium with increasing intake.

It follows that your need depends on sun, season, skin type and body weight. Whether 1,000 IU a day is enough or you need more is decided by the measurement, not by a rule of thumb.

Then the label calculation. Manufacturers state IU, labs and authorities state µg. The bridge is simple: 1 µg = 40 IU. With that you can read any label:

• 1,000 IU = 25 µg
• 2,000 IU = 50 µg
• 4,000 IU = 100 µg
• 5,000 IU = 125 µg
• 10,000 IU = 250 µg

And now the point where most people go wrong: The big number on the pack is not your daily dose. What counts is the dose divided by the rhythm. A tablet with 5,000 IU is not a daily ration but a depot dose. Take it every five days and you land at 1,000 IU a day on average, which is 25 µg. The same tablet taken daily would be 5,000 IU a day. Same product, completely different result, just because of the rhythm.

This is how our Vitamin D3 Depot + K2Pure® puts the calculation into practice: one tablet with 5,000 IU (125 µg) every 5th day, 1,000 IU a day on average, with no daily swallowing. If your second measurement shows that your need is higher, talk to your doctor about the right amount instead of guessing. Count everything else you take as well: vitamin D is in multivitamins, in combination supplements and in some omega-3 oils. Those amounts count towards your daily total.

With K2 form and amount matter: MK-7, with the amount in micrograms. Our depot brings 100 µg of K2Pure® per tablet. And because both vitamins are fat-soluble: take them with a meal that contains fat. A spoonful of oil on a salad, nuts, cheese, avocado, that is plenty. The time of day does not matter, the fat does.

What to look for when buying

Between two D3+K2 tubs on the shelf there are often worlds. These points separate a good supplement from an arbitrary one:

• MK-7, not MK-4. This is the most important criterion for K2. MK-7 stays in the blood much longer, MK-4 has practically vanished after a few hours. If the tub only says "vitamin K2" without a form, that is not a good sign.
• A branded raw material. Good manufacturers name their K2, for instance K2Pure®. A branded raw material means defined origin and tested quality, not an anonymous powder from the cheapest batch. Our depot contains K2Pure® with over 99 % all-trans.
• Both amounts separately. IU or µg for D3, µg for K2, right on the label.
• Work out the daily dose. Dose divided by rhythm. A product with 5,000 IU is not automatically "too high" and one with 1,000 IU not automatically "enough". Only the intake recommendation together with your blood level decides.
• A clear intake recommendation. If a tub shows a big number but nobody writes at what interval to take it, half the information is missing.
• Lab-tested. With fat-soluble vitamins you want to know that what is on the label is inside, and nothing else. We have raw materials and every finished batch tested independently in a lab.

Honestly assessed

What is established is the part that counts: Vitamin D contributes to the normal absorption/utilisation of calcium and phosphorus. Vitamin D contributes to the maintenance of normal bones, to the maintenance of normal teeth and to the normal function of the immune system. Vitamin K contributes to the maintenance of normal bones and to normal blood clotting.

Not established is a rule-of-thumb number that suits everyone. Your body, your sun and your weight decide. So: get measured instead of guessing. If you go clearly beyond the usual in your dose, medical monitoring of your blood level stays your companion. With kidney disease and with medication taken regularly, you discuss the vitamin D amount with your doctor first. If you take anticoagulants, the same applies to K2, because vitamin K contributes to normal blood clotting. Our high-dose depot is not suitable for pregnant or breastfeeding women, or for children and adolescents.

Matching Products from Scheunengut

Our Vitamin D3 Depot + K2Pure® is built on the logic of this guide: high-dose 5,000 IU (125 µg) vitamin D3 and 100 µg vitamin K2 as the branded raw material K2Pure® (MK-7, over 99 % all-trans) in one tablet that you take only every 5th day. That is 1,000 IU of D3 a day on average, and a tub of 180 tablets lasts 900 days. The tablet is plant-based, vegan, lab-tested and made in Germany. Vitamin D contributes to the maintenance of normal muscle function and to the normal function of the immune system, vitamin K to the maintenance of normal bones.

A good match: the Magnesium Complex made from four bioactive magnesium sources with 400 mg of elemental magnesium per daily dose. Magnesium contributes to normal muscle function and to the reduction of tiredness and fatigue. Scheunengut stands behind both: since 2012, without investors, focused on pure raw-material quality.

Frequently Asked Questions (FAQ)

How much vitamin D3 should I take per day?

Your blood level tells you. Have 25-OH-D measured, start with an amount and measure again after a few months. An analysis of healthy adults found that blood levels rise steepest at small amounts, and that people who weigh more need more for the same level. In research with healthy men, up to 10,000 IU a day was given over 20 weeks. Our depot delivers 1,000 IU a day on average.

Can I take more vitamin D3 with K2?

K2 does not replace the blood test. How much D3 you need depends on your blood level. K2 comes along because both work on the same calcium pathway: vitamin D contributes to the normal absorption/utilisation of calcium and phosphorus, vitamin K contributes to the maintenance of normal bones. If you take vitamin D in a high dose, adding K2 right away makes sense.

How do I convert IU into micrograms?

One microgram of vitamin D equals 40 IU. So 1,000 IU is 25 µg, 4,000 IU is 100 µg and 5,000 IU is 125 µg. That one conversion is enough to classify any label.

Why is one tablet every five days enough with a depot?

Because vitamin D is fat-soluble and your body can store it. It does not have to be topped up daily. 5,000 IU spread over five days works out at 1,000 IU, or 25 µg, per day on average. A tub of 180 tablets lasts 900 days.

How much K2 should a combination product contain?

What matters is that form and amount are declared: MK-7 and the amount in µg. Our tablet contains 100 µg of vitamin K2 as K2Pure® (MK-7, over 99 % all-trans), which is 133 % of the nutrient reference values.

MK-7 or MK-4: which is better?

MK-7. It stays in the blood much longer, while MK-4 is barely detectable after a few hours. That is why MK-7 is in practically every serious K2 supplement.

When is the best time to take D3 and K2?

With a meal that contains some fat. Both vitamins are fat-soluble and are absorbed better that way. The time of day does not matter; you can take them in the morning or in the evening.