Vitamin D

Vitamin D contributes to the maintenance of normal bones, normal muscle function and the normal function of the immune system. At Fitsport you can choose vitamin D3 supplements or combinations with K2, calcium and other nutrients. Don't compare the pack alone: what matters is how much vitamin D a serving contains, what form the product comes in and who it's intended for according to the label.

What is vitamin D needed for?

Vitamin D is a fat-soluble vitamin. We get it from food and supplements, and the body also produces it in the skin when exposed to sunlight. The need for a supplement is individual – the season or tiredness alone doesn't show how much a particular person needs.

Vitamin D contributes to:

• normal absorption and utilization of calcium and phosphorus;
• the maintenance of normal bones and teeth;
• the maintenance of normal muscle function;
• the normal function of the immune system.

These functions don't mean that a higher amount of the vitamin will give better results or protect against disease. Add up the total amount of vitamin D from all the products you take at the same time.

What's the difference between vitamin D and vitamin D3?

Vitamin D is the general name, while D3, or cholecalciferol, is one of its forms. Another form is called D2. So the labels “vitamin D” and “vitamin D3” don't necessarily mean products with different purposes: you'll find the exact ingredient in the composition.

This Fitsport category includes D3 products in capsules and combinations in tablets. If the origin of the raw material, the capsule shell or suitability for vegans matters to you, check the specific label. The name D3 alone doesn't answer all of these questions.

Which vitamin D is best for your needs?

First choose the composition and amount you need, then a convenient form. The most ingredients or the highest number on the pack aren't in themselves signs of the best product.

• Vitamin D per serving – compare micrograms or international units and check how many capsules or tablets make up a serving.
• Composition – whether you're looking for vitamin D3 only or also K2, calcium, magnesium, zinc or omega fatty acids.
• Form – whether a capsule or a tablet is more convenient for you; when switching products, don't carry over the dosage automatically.
• Additional ingredients – consider the oil, capsule shell, allergens and other aspects of the composition that matter to you.

For example, Amix GreenDay Vitamin D3 2500 I.U. 90 caps is a D3 capsule option, while Raw Powders Vitamin D3 + Vitamin K2 90 tabs combines two vitamins in one tablet. These are examples from our range, not a recommendation of a dose that suits everyone. Before choosing, check the product's current label and directions for use.

Vitamin D3 and K2: when does the composition of a combination matter?

A D3 and K2 combination contains two different substances. Vitamin K contributes to normal blood clotting and to the maintenance of normal bones. Its presence is no basis for claiming that a vitamin D supplement is automatically better absorbed or suitable for everyone.

If you already take multivitamins or a mineral complex, compare the labels of all your products. D3 can be found not only in a standalone supplement but also in combinations with calcium, magnesium or omega fatty acids. One combination can be convenient, but it's important not to duplicate substances you don't need.

People taking warfarin or other medicines that block the action of vitamin K should consult a doctor before choosing a supplement containing K2. Don't change your prescribed medication or how you take it on your own.

What do µg and IU on the pack mean?

The amount of vitamin D is given in micrograms (µg) or international units (IU). 1 µg of vitamin D equals 40 IU. So 25 µg is 1,000 IU, and 100 µg is 4,000 IU. This is a unit conversion, not a recommendation to take these amounts.

The tolerable upper intake level of vitamin D set by EFSA for adults is 100 µg per day. It covers the total amount from food and supplements and is not a recommended daily dose. That's why a 4,000 IU product shouldn't be seen as a universal choice for everyone.

Do I need a vitamin D test before choosing a supplement?

Vitamin D status is assessed with the 25(OH)D blood test. However, not every healthy person needs to be tested as a precaution. Discuss with your doctor whether a test is needed and how to interpret the result, especially if you suspect a deficiency or are considering high doses.

Vitamin D price: what to compare before buying?

Assess the price of vitamin D together with the composition, the amount per serving and how long the pack will last according to the manufacturer's directions. The same number of capsules doesn't mean the same composition, and the prices of tablets and capsules aren't always directly comparable.

For example, if an illustrative 90-serving pack cost €12, one serving would cost about €0.13. It makes sense to compare this figure with a product with a similar vitamin D content and composition. This is an example calculation, not a current product price.

You'll see current prices, promotions and availability on the product pages. A lower price or higher concentration shouldn't outweigh whether the product is right for you.