If your goal is simply to maintain vitamin D levels, a high-quality D3 will suffice. D3+K2 (usually MK-7) is a reasonable option to consider if you regularly take D in a higher dose, care about bone and vascular balance, and are low in vitamin K in your diet — not because “D3 alone doesn’t work.”
What is D3 and what is K2?
D3 (cholecalciferol) helps regulate calcium and phosphorus metabolism and is the main form for increasing blood levels of D. K2 (menaquinone, often MK-7) is involved in proteins that direct calcium to the bones; dietary K comes mainly from green and fermented foods.
| Property | Only D3 | D3 + K2 |
|---|---|---|
| Purpose | D status, immunity, bones (with Ca/P) | D + K2 together in one capsule |
| Complexity | Simple, cheaper | More components |
| Suitable | Most everyday | Who wants a combo/higher D-dose routine |
| Note | Do not exceed the recommended dose without supervision. | Read the K2 form (MK-7 vs MK-4) and dosage on the label |
When to choose only D3?
Choose D3 if:
- you want a clear, inexpensive, and well-researched base supplement;
- eat a varied diet (including sources of vitamin K) or take K separately;
- you are just starting out and first want to know how D3 fits alone.
Typical retail doses are 1000–4000 IU; individual needs depend on blood, body weight, season, and doctor's recommendation.
When to consider D3+K2?
Consider a combo if you take Dd daily and want one capsule that also contains K2 (MK-7 is the usual long-acting form). It is not a substitute for a balanced diet or calcium sources. If you are taking blood-thinning medications (e.g. K antagonists), ask your doctor before starting K2 .
D2 vs D3 in brief
D3 is the preference for most people to increase their D levels. D2 remains a primarily herbal option when D3 is not suitable due to source.
How do I buy from Omegafit?
View vitamins and minerals category : filter D3 or D3+K2, compare IU dosage and number of capsules. Free delivery from €49.
Frequently asked questions
Is D3 without K2 dangerous?
In reasonable doses, D3 has been widely used. Problems arise mainly with chronic overdose. Do not “mega-dose” without a laboratory and a specialist.
Do I need to have a blood test?
Recommended, especially if you have symptoms, are in a risk group, or plan to take a higher dose for a long time.
Can children take the same product?
Children's doses are different — follow the pediatrician's and manufacturer's instructions.
Informative content from the Omegafit editorial team. Not a substitute for medical advice.