Buy Vitamin D3 at VitaminExpress!
Vitamin D3 – also known as the “sunshine vitamin” – is one of the most important fat-soluble vitamins for the human body. It is mainly produced in the skin by UV-B radiation and supports numerous bodily functions, from bone health to immune defence. Since many people in Germany, Austria, and Switzerland don't get enough sunlight, especially during the winter months, targeted supplementation with a high-quality vitamin D3 product makes particular sense. At VitaminExpress, you'll find a carefully selected range of vitamin D3 supplements: from classic capsules and convenient drops to innovative liposomal formulations and combination products with vitamin K2. All products come from verified brand manufacturers and are tested for the highest purity and bioavailability.
What is vitamin D3, and why is it so important?
Vitamin D3 (cholecalciferol) is the body's own form of vitamin D, which is synthesised in human skin through sunlight. Unlike vitamin D2 (ergocalciferol), the body converts D3 more efficiently into its biologically active form, 1,25-dihydroxyvitamin D (calcitriol).
The key functions of vitamin D3 at a glance:
- Supports the normal absorption and utilisation of calcium and phosphorus
- Helps maintain healthy bones and teeth
- Promotes normal muscle function and prevents muscle weakness
- Strengthens the immune system and supports normal immune function
- Plays a role in cell division
- Helps maintain normal calcium levels in the blood
Vitamin D3 deficiency: Who is particularly at risk?
It is estimated that a large portion of the population in Central Europe has suboptimal vitamin D levels, particularly during the autumn and winter months. Those at risk include:
- People who spend little time outdoors or work in an office
- older people aged 65 and over, whose skin produces vitamin D less efficiently
- People with darker skin, as higher levels of melanin reduce UV-B absorption
- Vegans and vegetarians, as vitamin D3 is mainly found in animal-based foods
- Pregnant and breastfeeding women, who have increased requirements
- People with malabsorption disorders (e.g., Crohn's disease, coeliac disease)
What should the vitamin D3 dosage be?
The optimal vitamin D3 dose depends on your current blood level (25(OH) vitamin D), your age, your body weight, and your personal risk profile. The German Nutrition Society (DGE) recommends a daily intake of 800 IU (20 µg) for adults if they cannot ensure sufficient vitamin D production through sunlight.
Practical guidelines for supplementation:
- 800–1,000 IU daily: maintenance dose for the general population
- 2,000–3,000 IU daily: For mild deficiency or preventive use
- 5,000 IU daily: In cases of proven deficiency, under medical supervision
- 20,000 IU as a loading dose: For weekly intake (equivalent to approximately 2,857 IU per day)
Important: To accurately determine your personal needs, we recommend a vitamin D blood test. VitaminExpress provides convenient self-test kits for you to use at home.
Vitamin D3 and K2: Why does combining them make sense?
Vitamin D3 helps the body absorb calcium from the gut. Vitamin K2 (especially in the form of MK-7) ensures that the calcium you absorb is transported to where it belongs – namely your bones and teeth – and isn't deposited in your artery walls. That's why many experts recommend taking both vitamins together, especially with higher D3 doses of 2,000 IU or more per day.
At VitaminExpress, you'll find high-quality D3+K2 combination preparations in various forms: capsules, drops, and liposomal liquid formulations for maximum absorption.
Which form is right for you?
Our range offers you the perfect choice for every need:
- Vitamin D3 capsules: convenient, precisely dosed, and ideal for daily use. Also available in vegan-certified versions.
- Vitamin D3 drops: Flexible dosing, rapid absorption, and particularly suitable for those who prefer not to swallow capsules. Also ideal for children.
- Liposomal vitamin D3: Cutting-edge technology for maximum bioavailability – the liposome coating protects the active ingredient and significantly improves its absorption into the blood.
- Depot capsules (20,000 IU): Designed for weekly use – convenient for those who prefer less frequent dosing.
Quality and safety: what VitaminExpress prioritises
All vitamin D3 products in our range are selected according to strict quality criteria. We place particular emphasis on the following points:
- Production according to GMP (Good Manufacturing Practice) standards
- Declared active ingredient levels confirmed by independent laboratory tests
- Certifications for vegan formulations using animal-free raw materials (from lichens)
- Free from unnecessary additives, artificial colours, and preservatives
- Transparent information on origin and comprehensive labelling
Frequently Asked Questions About Vitamin D3 Supplements
Vitamin D2 (ergocalciferol) comes from plant sources and is mainly obtained by irradiating yeast fungi. Vitamin D3 (cholecalciferol), on the other hand, is the form that the human body itself produces through sunlight. Studies show that vitamin D3 raises blood levels much more effectively and sustainably than D2 – which is why D3 is the preferred form of supplementation.
Vitamin D3 is usually taken over longer periods, as the body's own production practically stops in our latitudes, especially from October to April. Many people take D3 all year round, potentially reducing the dose in summer. Have your levels checked regularly – the ideal range is 40–60 ng/ml (100–150 nmol/l).
Vitamin D3 is fat-soluble, so it's best taken with a meal that's high in fat – for example, with breakfast or lunch. Studies show that absorption can be improved by up to 32% when taken with healthy fats (e.g., olive oil, avocado, nuts).
It's impossible to overdose on vitamin D3 from natural sunlight. Taking supplements at consistently very high doses (regularly over 10,000 IU/day for months) could theoretically lead to hypervitaminosis D. Symptoms would include nausea, weakness, or calcium deposits. Within the recommended dosage range of up to 4,000–5,000 IU per day, intake is considered safe. Please consult a doctor if you are taking very high doses.
Yes. Vegan vitamin D3 is derived from lichens and is chemically identical to animal D3 (which is typically obtained from sheep wool lanolin). Studies show no relevant differences in bioavailability. At VitaminExpress, we offer certified vegan vitamin D3 products in various dosages.
For daily doses of up to 1,000 IU, additional K2 supplementation is generally not necessary, provided your diet provides enough K2 (e.g., through fermented foods or hard cheese). From a dose of 2,000 IU and above, many experts recommend supplementing with vitamin K2 (MK-7) to optimise calcium distribution and prevent excessive calcification of the blood vessels.
Possible signs of a vitamin D deficiency include: persistent tiredness and a lack of energy, frequent infections, muscle weakness or cramps, low mood and depressive feelings, as well as bone and back pain. However, these symptoms are not specific. A reliable diagnosis can only be made with a blood test (25(OH) vitamin D). With our vitamin D self-test, you can conveniently check your levels from the comfort of your own home.
The “best” supplement depends on your personal needs: for a simple daily basic intake, we recommend vitamin D3 drops (5,000 IU) or capsules (1,000–5,000 IU). For increased needs or for a quick correction, depot capsules (20,000 IU) are a good choice. For maximum absorption, we recommend liposomal formulations. Combination supplements with K2 are ideal for higher dosages. All supplements available at VitaminExpress are quality tested.
The DGE recommends 400 IU per day for infants and 800 IU per day for children up to 14 years of age, unless they can produce enough on their own. Our specially dosed vitamin D3+K2 drops for children are particularly suitable for toddlers and children. You should always check with your paediatrician before giving it to your child.
Since vitamin D3 is fat-soluble, its absorption improves when taken with fat. You can take it on an empty stomach, but it's less effective. Ideally, take D3 with a main meal that contains healthy fats. Exception: Liposomal vitamin D3 formulations – thanks to their liposomal coating, these can be absorbed almost regardless of simultaneous fat intake.