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.”
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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.