Vitamin D3 4000 IU

IU and µg: what 4000 means

Vitamin D is measured in two units. EU nutrition tables use micrograms (µg), while many front labels still use international units (IU). 1 µg equals 40 IU, so 4000 IU is 100 µg. The reference intake (NRV) for adults is 5 µg, which is why the label shows 2000% NRV.

100 µg is also the tolerable upper intake level EFSA set for adults: the highest daily intake from all sources together that EFSA considers unlikely to cause harm over the long term. A single 4000 IU capsule or tablet reaches that level by itself.

Vitamin D3 4000 IU products in our range

Who chooses 4000 IU

OstroVit labels set the 4000 IU daily dose for healthy adults over 75. The VEGE tablets show how the maker splits it: half a tablet (2000 IU) for adults under 75 and a whole tablet for those over 75. Some people take 4000 IU because a doctor checked their vitamin D level with a blood test and suggested this dose. Talk to your doctor before you take a high dose for months, and never go above the dose on the label. If you want less per day, the main vitamin D3 category also has 1000 IU and 2000 IU products.

Take it with a meal that contains fat

Vitamin D dissolves in fat, not in water. The labels say to take it with a meal, and the NIH Office of Dietary Supplements notes that vitamin D is absorbed better with food that contains some fat. The softgel already holds the vitamin in sunflower oil. The time of day is up to you. Taking it at the same meal every day makes it easier to remember.

D3 with K2

Three of the four products add vitamin K2 as menaquinone-7 (MK-7), 100 µg per tablet or capsule, which is 133% of the 75 µg NRV. Vitamin D and vitamin K both have authorised claims about normal bones, and that is the usual reason for combining them. If you take medication that affects blood clotting, ask your doctor before you start any product with vitamin K.

Count vitamin D from other products

Vitamin D also turns up in multivitamins and in some fish oil capsules. OstroVit Omega-3 + ADEK and Omega 3 D3 + K2 each contain 2000 IU. Taken alongside a 4000 IU product, that comes to 6000 IU (150 µg) a day, above the EFSA upper level.

EU health claims

Regulation (EU) No 432/2012 allows these statements for products whose daily dose gives at least 15% of the NRV of the vitamin:

• Vitamin D contributes to normal absorption/utilisation of calcium and phosphorus.
• Vitamin D contributes to normal blood calcium levels.
• Vitamin D contributes to the maintenance of normal bones.
• Vitamin D contributes to the maintenance of normal teeth.
• Vitamin D contributes to the maintenance of normal muscle function.
• Vitamin D contributes to the normal function of the immune system.
• Vitamin K contributes to the maintenance of normal bones.
• Vitamin K contributes to normal blood clotting.

Questions

How many µg is vitamin D 4000 IU?

100 µg. To convert, divide the IU figure by 40. 2000 IU is 50 µg and 1000 IU is 25 µg.

Is vitamin D3 from lichen different?

Lichen provides the same compound, cholecalciferol, from a plant source, so the VEGE products suit people who avoid animal ingredients. Their capsule shell is plant cellulose (HPMC), while the standard softgel is made of gelatin.

Can I split the tablet?

The VEGE tablet label gives a half-tablet dose of 2000 IU for adults under 75. For the other products the label dose is one whole unit.

Sources

• Regulation (EU) No 1169/2011, Annex XIII (reference intakes)
• Regulation (EU) No 432/2012 (permitted health claims)
• EFSA (2023): Scientific opinion on the tolerable upper intake level for vitamin D
• NIH Office of Dietary Supplements: Vitamin D fact sheet

Content reviewed by Inese Kalniņa, dietitian.

2026-09-30