Vitamin D Supplement: Recognising Quality (Oil Base, Dose, D3)

It is November, the sun disappears behind the rooftops by four, and you reach for vitamin D. Good decision - only: not every supplement is equally well made. So here is the direct answer up front:

You can recognise a good vitamin D supplement by four features: the form vitamin D3 (cholecalciferol), an oil base as the carrier (because vitamin D is fat-soluble), a dose clearly stated in international units (IU) or micrograms, and - if combined - a sensible K2 form such as MK-7. Plus few excipients and a traceable origin.

Vitamin D is among the most commonly supplemented nutrients, especially in the sun-poor months. And it has many officially approved claims - more on that shortly. First, the form.

D3 or D2: the vitamin form

Vitamin D comes as D3 (cholecalciferol) and D2 (ergocalciferol). D3 corresponds exactly to the form your body also produces itself via the skin when UV-B light strikes it - and is generally regarded as readily usable. Most high-quality supplements therefore rely on D3.

A common misconception: that D3 is necessarily of animal origin. Classically it comes from lanolin (wool fat) from sheep, but there is vegan D3 from lichen, which provides the same cholecalciferol form. Anyone avoiding animal raw materials should look for a corresponding note. You can read more about the difference in Vitamin D3 vs. D2.

Oil base: why it matters

Vitamin D is fat-soluble - that is the key to understanding it. For it to be well absorbed, an oil as a carrier is advantageous. With drops you recognise this by an oil base (e.g. MCT or olive oil), with capsules by softgels containing oil. Plain tablets without fat are considered less ideal for absorption - if you take them, then with a meal containing fat. Whether drops or capsules suit you better is clarified in Vitamin D: Drops or Capsules?

Reading the dosage correctly

The dose is stated in international units (IU) or in micrograms (µg). You should know the conversion so that no figure confuses you:

A good supplement clearly states the dose per serving and allows a sensible adjustment. How high the individual requirement is depends on sun exposure, season and blood level - Vitamin D dosage by blood level provides orientation. Principle: more is not automatically better. Vitamin D is fat-soluble and is stored, so very high doses without monitoring do not make sense.

Combination with K2

Vitamin D is often combined with vitamin K2. Both are distinct vitamins with their own approved claims: vitamin D contributes to the maintenance of normal bones, and vitamin K likewise contributes to the maintenance of normal bones. With K2 it is worth looking at the form - the well-studied MK-7 is considered stable and long-lasting in the body. Details on the combination can be read in Vitamin D3 & K2 combination and Vitamin D and K2 together.

Why so many people supplement, especially in winter

The body produces vitamin D via the skin - but only if enough UV-B light arrives. At our latitudes the sun stands too low from roughly October to March for the body's own production to work to any notable degree. Add to that everyday life in the office, clothing and sun protection. This is precisely why so many people reach for vitamin D in the dark season: the natural source simply does not flow. Vitamin D is hard to cover through diet - notable amounts are found almost exclusively in oily fish such as salmon or herring, and to a lesser extent in egg yolk and some mushrooms. Anyone with little sun and little fish will find further orientation in Nutrients with little sunlight and Dark season, light & vitamin D. This describes the context of use - why people supplement - not a curative effect.

Origin: vegan D3 or wool fat

As mentioned above, there are two raw-material routes: lanolin (animal) and lichen (vegan). Reputable manufacturers clearly label vegan D3. There are also differences in the capsule shells: gelatine is of animal origin, cellulose capsules are plant-based. Features of vegan products are summarised in Recognising vegan supplements.

What the research is looking into

The role of vitamin D for bones, muscle function, the immune system and calcium utilisation is well documented and is reflected in the numerous approved EU claims. Beyond that, research is intensively concerned with the prevalence of insufficient vitamin D supply in sun-poor regions and winter months, with the interplay of vitamin D, K2 and calcium, and with the question of how individually the requirement turns out to be depending on skin type, sun exposure and lifestyle. Specific curative effects cannot be derived from this; the focus is on supplying a vitamin that the body can only produce itself with difficulty when sunlight is lacking.

Which benefit is proven? The approved claims

Several claims are approved for vitamin D in the EU. Vitamin D contributes

• to the maintenance of normal bones and normal teeth,
• to the maintenance of normal muscle function,
• to a normal function of the immune system,
• to a normal absorption and utilisation of calcium and phosphorus,
• to normal cell division.

These claims apply with adequate intake, regardless of the dosage form.

How do I recognise a good vitamin D supplement? The checklist

Honestly put into perspective

Established and approved are the stated functions of vitamin D - from the bones to the immune system. The quality features (D3, oil base, clear dose) help you recognise a well-made supplement. What does not hold: that a higher dose would be better across the board. Because vitamin D is fat-soluble and is stored, very high doses without blood-level monitoring do not make sense. The individual requirement is best determined via a blood test - that is more precise than any rule of thumb. In case of illness, during pregnancy and breastfeeding, and when taking medication, the dosage should be medically supervised.

Suitable products from Scheunengut

You will find vitamin D supplements with an oil base and clear dosage in the category Vitamin D, and matching additions under Vitamins. For the combination with K2 it is worth a look at Vitamin K.

Read on: Vitamin D deficiency: signs, Vitamin D: how long until it takes effect, Nutrients with little sunlight, Calcium and vitamin D together and Which vitamin D supplement to buy?

Frequently Asked Questions (FAQ)

How do I recognise a good vitamin D supplement?

By the form vitamin D3 (cholecalciferol), an oil base as the carrier for absorption, a dose clearly stated in IU or µg per serving and - if combined - a good K2 form such as MK-7. Plus few excipients and a traceable, lab-tested origin.

Is D3 better than D2?

D3 (cholecalciferol) corresponds to the form the body produces itself via the skin, and is generally regarded as readily usable. Most high-quality supplements therefore rely on D3. There is also vegan D3 from lichen as an alternative to the animal-derived D3 from wool fat.

Why is an oil base useful for vitamin D?

Vitamin D is fat-soluble and is absorbed better together with fat. Drops on an oil base or oil softgels are therefore advantageous. Plain tablets without fat should be taken with a meal containing fat.

How do I convert micrograms to IU?

1 microgram (µg) of vitamin D corresponds to 40 international units (IU). So 25 µg is 1000 IU and 50 µg corresponds to 2000 IU. A good supplement states the dose clearly per serving.

How we at Scheunengut ensure tested purity from raw material to tin is explained on our page about the Clean Earth Badge.