When is vitamin D considered high strength?

Vitamin D is considered high-strength from approximately 4,000 IU per day or per capsule.

Why is Vitamin D3 15,000 combined with magnesium?

Magnesium is a key partner that helps the body properly utilize vitamin D. The combination of both nutrients supports optimal absorption and effectiveness.

What is high strength vitamin D?

High strength vitamin D3 refers to concentrated amounts of the nutrient in a single product. It's often used when vitamin D levels are very low and need to be corrected more rapidly. Our Vitamin D3 15,000 supplement contains 15,000 IU (International Units) of vitamin D3 per capsule—equivalent to a daily intake of about 2,143 IU (53.6 µg).

How quickly does high strength vitamin D work?

Everyone responds differently. However, a higher dose can help normalize levels more quickly. In general, it takes several weeks or even months for the body to correct a deficiency. It’s best to check with a healthcare professional for guidance.

How long should I take high strength vitamin D?

Vitamin D can be taken year-round. In case of deficiency, it's recommended to adjust the dosage in consultation with a healthcare professional and monitor levels via lab testing—until your vitamin D levels are back within a healthy range.

What dosage of vitamin D is considered too high?

Mehr als 4.000 I.E. Vitamin D pro Tag gelten als obere sichere Grenze – langfristig kann eine solche Dosis zu viel sein. Deshalb solltest du höhere Mengen nur nach ärztlicher Rücksprache einnehmen.Auch wenn 15.000 I.E. Vitamin D pro Kapsel zunächst viel erscheinen: Wenn du nur eine Kapsel pro Woche einnimmst, entspricht das einer durchschnittlichen Tagesdosis von etwa 2.143 I.E. – und die liegt im sicheren Bereich. Denn Vitamin D ist fettlöslich und kann im Körper gespeichert werden. So lässt sich der Bedarf auch durch eine wöchentliche Einnahme gut decken.

Can high-dose vitamin D cause diarrhea?

Yes, very high doses of vitamin D can, in rare cases, lead to diarrhea—especially if calcium levels in the blood rise too much. This generally only happens after long-term overdosing (more than 10,000 IU per day) or a single, extremely high dose (e.g. 100,000 IU). Diarrhea is just one possible warning sign, along with symptoms like nausea, abdominal pain, or confusion.

Is a weekly dose of 15,000 IU of vitamin D safe?

Yes, 15,000 IU per week is considered safe, as it falls below the upper daily intake limit when averaged over seven days. At BIOGENA, we offer this practical weekly format to make supplementation easy and consistent. Still, we recommend checking your vitamin D levels regularly and consulting a healthcare professional if you have any concerns.

Does high strength vitamin D require a prescription?

No, high strength vitamin D usually does not require a prescription and can be freely purchased as a dietary supplement.

Where are BIOGENA preparations manufactured?

BIOGENA preparations are carefully manufactured in our own production facility, BIOGENA Good Health World (Salzburg, Austria), to a unique manufacturing standard. We are certified according to FSSC and GMP - Good Manufacturing Practice and have organic, halal and kosher certification. The quality-tested raw materials come from premium brand raw material manufacturers - sourced directly from the world market leaders.

Where can I buy BIOGENA preparations?

BIOGENA cooperates with respected physicians and therapists in many different countries. With them, you are in good hands. You can also buy our products from our BIOGENA stores in Austria (Vienna, Linz, Salzburg, Graz, Natternbach), Germany (Freilassing, Frankfurt, Düsseldorf, Munich, Hamburg) and soon in London (UK) as well as online at www.biogena.com.

What does the term “pure substance principle” mean?

At BIOGENA, “pure substance principle” means that we do not use technological additives which are used for the fully automated manufacturing of tablets, capsules and pills (e.g. anticaking or release agents and so forth) or additives that are used for optical reasons or for enhancing the taste of the products (artificial aroma, colouring agents, coatings etc.). Due to a semi-automatic manufacturing process, we can avoid these substances that often have a higher proportion in customary products than the actual active ingredients. In the case of nutritional supplements, additives have to be indicated in the list of ingredients. Here, the patient or customer can get useful information. Concerning the single ingredients, we also care for our raw materials to be free of carrier substances. In cases where this is not possible, we use natural food components such as maltodextrin, cellulose powder or calcium carbonate. The majority of our ingredients is produced exclusively for us – free of carrier substances (e.g. our enzymes our probiotics: other manufacturers often use lactose as a carrier – the product batches produced for us are explicitly without carriers).

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Biogena, Vitamin D₃ 15.000, Bottle, white, Micronutrient special preparation with vitamin D₃ in high dosage With magnesium

Biogena Essentials

Vitamin D3 15,000 IU

Premium high strength vitamin D supplement (15,000 IU) for your weekly routine

15,000 IU of vitamin D3 per capsule
Simple and convenient: just one capsule per week as an alternative to daily dosing.
With magnesium – a key mineral that supports the maintenance of normal bones.*
Perfect for topping up your vitamin D levels during times of low sun exposure.
Vitamin D contributes to the normal function of the immune system, muscles, bones, and teeth, as well as to maintaining normal calcium levels in the blood.*

€36.90

€0.31 / caps.

Stock AvailableDelivery within 5-7 working days

incl. VAT.

This product fits to these categories

Vitamines Vitamin D Immune support

Gluten-free

Lactose-free

Support during increased needs

Vegetarian

For weekly supplementation

Convenient capsule form

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High-dose vitamin D: Power Support for the body

Our high-dose vitamin D makes it simple: just one capsule a week provides you with 15,000 IU of vitamin D3—equivalent to around 2,143 IU per day—for practical, no-fuss supplementation.

Why choose high strength vitamin D?

Contributes to the normal function of the immune system*
Supports normal absorption and utilization of calcium and phosphorus*
Plays a key role in maintaining strong muscles, healthy bones, and normal teeth*
With magnesium – a key mineral in vitamin D metabolism

Ideal for replenishing your vitamin D stores, especially in autumn, winter, or when sun exposure is limited

Discover our high-dose vitamin D today!

Vitamin D3 15,000 IU in detail

What our customers say

Moderne Kunstgalerie mit zeitgenössischen Sitzgelegenheiten, abstrakten Porträts an den Wänden, warmer Beleuchtung und einer Mischung aus Holz- und Metallelementen in der Dekoration.

100% Clean Label – no hidden extras

At BIOGENA, transparency isn’t just a promise – it’s our everyday practice. We follow the pure substance principle: 100% quality, mostly free from colorants, preservatives, and technical additives. The result? Outstanding tolerability (97%) and a recommendation rate of 95% – confirmed by over 18,000 doctors, therapists, and more than half a million customers.

EVERY batch: independently tested
Active ingredient content – guaranteed
100% free from artificial colors/flavors, titanium dioxide, GMOs, nanoparticles, magnesium stearate
In-house production in Salzburg (BIOGENA Good Health World)
Premium raw materials sourced directly from global market leaders

Learn more

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What sets us apart

For us, knowledge is more than just information – it’s inspiration. We aim to make health tangible, share what we know, and pass on our passion for it. At the same time, we act with responsibility for our environment – with conviction and heart.

Independent family business, led by founder Dr. Albert Schmidbauer
100% Austrian science in every product
Handcrafted production – uncompromising since 2006
Eco-friendly packaging in the BIOGENA GreenPE bottle
Research & development at the highest level – with the largest scientific team in the industry
Double Climate Positive

Learn more about the BIOGENA story

Ein Arbeiter in Schutzausrüstung gießt eine Substanz in einen großen Industriekessel in einer hellen, modernen Einrichtung.

Production of our premium supplements

At BIOGENA, quality knows no compromises. From raw material sourcing to research and development, all the way to our in-house manufacturing at BIOGENA Good Health World in Koppl near Salzburg – every step is transparent and traceable.

Brand-name raw materials with certified quality seals
EVERY batch independently tested by the German LEFO Institute
Certified according to FSSC 22000

Quality and research

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FAQs

Frequently asked questions about high-strength vitamin D supplementation

Laboratory test certificates

Laboratory analysis Heavy metals,Vitamin D3

LEFO-Certificate Vitamin D3 15.000 - p-53633

PDF

Laboratory analysis Heavy metals,Magnesium,Vitamin D

LEFO-Certificate Vitamin D3 15000 - p-55104

PDF

Laboratory analysis Microbiology,Vitamin D

LEFO-Certificate Vitamin D3 15000 - p-57089

PDF

Laboratory analysis Magnesium,Vitamin D

LEFO-Certificate Vitamin D3 15000 - p-57240

PDF

Laboratory analysis Vitamin D,Gluten

LEFO-Certificate Vitamin D3 15000 - p-58202

PDF

Laboratory analysis Microbiology,Vitamin D

LEFO-Certificate Vitamin D3 15000 - p-58211

PDF

Laboratory analysis Vitamin D

LEFO-Certificate Vitamin D3 15.000 - p-60247

PDF

Laboratory analysis Magnesium,Vitamin D

LEFO-Certificate Vitamin D3 15.000 - p-60246

PDF

Laboratory analysis Vitamin D

LEFO-Certificate Vitamin D3 15.000 - p-60245

PDF

Laboratory analysis Fructose,Vitamin D

LEFO-Certificate Vitamin D3 15.000 - p-60289

PDF

Uncompromising quality

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Vitamin D3 15,000 IU

High-dose vitamin D: Power Support for the body

Vitamin D3 15,000 IU in detail

Product description

Uses

Recommended intake

Ingredients

Important Product Notices

Storage advice

Package size

What our customers say

100% Clean Label – no hidden extras

What sets us apart

Production of our premium supplements

Discover what suits you

Frequently asked questions about high-strength vitamin D supplementation

When is vitamin D considered high strength?

Why is Vitamin D3 15,000 combined with magnesium?

What is high strength vitamin D?

How quickly does high strength vitamin D work?

How long should I take high strength vitamin D?

What dosage of vitamin D is considered too high?

Can high-dose vitamin D cause diarrhea?

Is a weekly dose of 15,000 IU of vitamin D safe?

Does high strength vitamin D require a prescription?

Where are BIOGENA preparations manufactured?

Where can I buy BIOGENA preparations?

What does the term “pure substance principle” mean?

Laboratory test certificates

Uncompromising quality

Sign up for our newsletter and get a €10 voucher