Written by the Plenthera team (trained in orthomolecular nutrition). Scientifically reviewed in October 2026. Last updated: 6 October 2026.
Vitamin D is the vitamin your skin produces itself under the influence of sunlight. In the Netherlands, the sun is too weak from October to March to produce enough, and extra vitamin D is advised all year round for various groups. At Plenthera you will find vitamin D3 as drops, vegan softgels and capsules, on its own or together with vitamin K2, calcium or omega 3.
Which vitamin D suits you?
Overview of the common forms of vitamin D on the market. At Plenthera we currently stock vitamin D3 in various forms and combinations.
| Form | Vitamin D3 per serving | Best for |
|---|---|---|
| Drops (at Plenthera) | 10 µg (children) or 25 µg (adults) | Flexible dosing, also for children |
| Vegan softgels (at Plenthera) | 75 µg | Higher dosage on advice, plant-based |
| D3 + K2 (at Plenthera) | 25–62.5 µg | Bones, together with vitamin K |
| D3 + omega 3 (at Plenthera) | 7.5–25 µg | Fish fatty acids and vitamin D in one |
| D3 + calcium and magnesium (at Plenthera) | 50 µg | Complete bone formula |
| Vitamin D2 | varies | Plant-based, less effective than D3 |
What is vitamin D?
Vitamin D is a fat-soluble vitamin that the skin produces under the influence of UVB radiation from sunlight. The body needs vitamin D for the absorption of calcium and phosphorus, for strong bones and teeth and for the immune system.
There are two forms: vitamin D3 (cholecalciferol), which the skin produces and which is found in oily fish, eggs and meat, and vitamin D2 (ergocalciferol) from mushrooms and yeast. In studies, D3 generally raises vitamin D status more effectively. In the liver and kidneys, vitamin D is converted into the active form.
You get relatively little vitamin D from food. That is why sunlight is the most important source. In autumn and winter the sun is too low in the Netherlands, so the skin produces hardly any vitamin D. Dark skin, rarely going outside, covering clothing and older age also reduce production.
Vitamin D and EFSA – what is scientifically recognised?
The following health claims, among others, are authorised for vitamin D (Regulation (EU) 432/2012):
"Vitamin D contributes to normal absorption/utilisation of calcium and phosphorus."
"Vitamin D contributes to the maintenance of normal bones."
"Vitamin D contributes to the maintenance of normal teeth."
"Vitamin D contributes to the normal function of the immune system."
The claims apply to products that provide at least 15% of the reference intake per daily serving, i.e. at least 0.75 µg vitamin D. This applies to all products in this category.
How much vitamin D do you need?
The reference intake (RI) on labels is 5 µg per day. The Gezondheidsraad (Health Council of the Netherlands) advises extra vitamin D via a supplement for a number of groups:
- 10 µg per day: children up to 4 years, pregnant women, women aged 50 to 70, and anyone with dark skin or who rarely goes outside or wears covering clothing.
- 20 µg per day: women and men aged 70 and over, and women aged 50 and over with osteoporosis.
EFSA sets the safe upper limit (UL) for adults at 100 µg per day from all sources combined; for children aged 1 to 10 years this is 50 µg and for infants 25 to 35 µg, depending on age. Dosages higher than the advice are intended for use in consultation with a doctor, for example with a measured deficiency.
Vitamin D at Plenthera and other forms on the market
Vitamin D3 on its own – at Plenthera
The Vitamine D3 Druppels from Vitals (20 ml) allow flexible dosing: 2 drops provide 10 µg (dosage for children), 5 drops 25 µg (dosage for adults). The Vitamine D3 3000 IE vegan softgels from Vitals (100 pieces) contain 75 µg D3 from algae per softgel; this is a higher dosage, within the safe upper limit, intended for those who need a higher intake on advice.
Vitamin D3 with K2 – at Plenthera
D3 + K2 (MK-7) from Plent (90 capsules) provides 50 µg vitamin D3 and 75 µg vitamin K2 per capsule. Vitamine K2 + D3 from Vitals (60 softgels) contains 25 µg D3 from algae and 90 µg K2 per softgel. KD Ultra from Arthur Andrew Medical (90 capsules) combines 62.5 µg D3 from lichen with vitamin K1 and the K2 forms MK-4 and MK-7. Ionic D3 + K2 from Trace Minerals (59 ml) is liquid; please note: the label serving of 4 drops provides 125 µg vitamin D, more than the safe upper limit of 100 µg per day. Only use this product in consultation with your doctor.
Vitamin D3 in combination – at Plenthera
Bot en Tandformule Pro from Vitals (60 tablets) combines, per 2 tablets, 200 mg calcium, 100 mg magnesium, 50 µg D3, 180 µg K2 and silicon. Ultimate Omega-D3 Sport from Nordic Naturals (60 softgels) provides, per 2 softgels, 25 µg D3 with 850 mg EPA and 425 mg DHA. Baby's DHA + Vitamine D3 from Nordic Naturals (60 ml) is a liquid fish oil with D3 for babies and toddlers, to be dosed according to the label.
Other forms on the market
Vitamin D2 (ergocalciferol) from yeast or mushrooms, D3 sprays and high-dose weekly dosages. We do not currently stock these.
How do you use vitamin D?
- Check which advice applies to you (10 or 20 µg per day) and choose a product to match.
- Follow the dosage on the label.
- Take vitamin D with a meal that contains some fat; the time of day does not matter.
- Add up vitamin D from several products, for example from a multivitamin, cod liver oil and an individual D3 product, and stay below the safe upper limit.
- Do you use coumarin-type blood thinners (acenocoumarol, phenprocoumon)? Then do not use products with vitamin K without consulting your doctor or anticoagulation clinic.
- Do you have a kidney condition, sarcoidosis or an elevated calcium level in the blood? Then consult your doctor first.
Myths and misconceptions about vitamin D
Myth 1: "A few times in the sun is enough for the whole winter."
Incorrect. The body does store vitamin D, but in the winter months the skin in the Netherlands produces hardly any vitamin D. That is why the advice on extra vitamin D for certain groups applies all year round.
Myth 2: "The more vitamin D, the better."
Incorrect. Above the safe upper limit, long-term use can lead to too high a calcium level in the blood. High dosages belong with a measured deficiency and consultation with a doctor.
Myth 3: "A sunbed is a good source of vitamin D."
A sunbed mainly gives UVA and little UVB, and UV radiation increases the risk of skin damage. A supplement is a safer way to top up vitamin D.
Combining vitamin D with other supplements
- Vitamin K: vitamin K contributes to the maintenance of normal bones.
- Calcium: calcium is needed for the maintenance of normal bones; vitamin D contributes to its normal absorption.
- Magnesium: magnesium contributes to the maintenance of normal bones.
- Omega 3: EPA and DHA contribute to the normal function of the heart (with 250 mg EPA and DHA per day).
- Vitamin A: the other fat-soluble vitamin from cod liver oil.
Frequently asked questions
Who needs extra vitamin D?
In the Netherlands, extra vitamin D is advised for, among others, children up to 4 years, pregnant women, women aged 50 and over, men aged 70 and over, and people with dark skin or who rarely go outside. This is usually 10 µg per day; for people over 70, 20 µg.
What is the difference between vitamin D2 and D3?
D3 (cholecalciferol) is the form the skin produces itself and in studies generally raises vitamin D status more effectively than D2 (ergocalciferol). All products in this category contain D3, partly from a plant source (algae or lichen).
Does vegan vitamin D3 exist?
Yes. Classic D3 comes from sheep's wool fat (lanolin), but D3 can also be obtained from algae or lichen. The vegan softgels and the K2 + D3 from Vitals contain D3 from algae, KD Ultra from Arthur Andrew Medical D3 from lichen.
Why vitamin D together with K2?
Both contribute to the maintenance of normal bones. Vitamin D contributes to the normal absorption of calcium; vitamin K is involved in proteins that bind calcium in bone. That is why they are often combined.
Can you take too much vitamin D?
Yes. EFSA sets the safe upper limit for adults at 100 µg per day from all sources combined, and for children aged 1 to 10 years at 50 µg. Long-term higher intakes can lead to too high a calcium level in the blood. Add up vitamin D from several products.
When is the best time to take vitamin D?
Vitamin D is fat-soluble. Take it with a meal that contains some fat. The time of day does not matter.
Sources
- Regulation (EU) 432/2012 – list of permitted health claims.
- EFSA NDA Panel (2023) – Scientific opinion on the tolerable upper intake level for vitamin D. EFSA Journal 21(8):8145.
- Gezondheidsraad (Health Council of the Netherlands) (2012) – Evaluation of the dietary reference values for vitamin D.
- Voedingscentrum (Netherlands Nutrition Centre) – Vitamin D.
- Tripkovic L et al. (2012). Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis. Am J Clin Nutr 95(6):1357–1364.
Disclaimer: This text is for informational purposes only and does not replace medical advice. Vitamin D is a food supplement, not a medicine. If in doubt or if you take medication, we recommend consulting a doctor or orthomolecular therapist first.