The best vitamin D3 K2 supplements in 2026. Compared on absorption, K2 form, dose, and value. Top picks: Sports Research, Thorne, and NatureWise.
Our Top 3 Picks at a Glance
- Best Overall: Sports Research Vitamin D3 + K2 — 5,000 iu d3 + 100mcg mk-7 k2 per softgel
- Best Premium: Thorne Vitamin D + K2 Liquid — liquid drops with metered dispenser for precise dosing
- Best Value: NatureWise Vitamin D3 5000 IU — 5,000 iu vitamin d3 per softgel in organic olive oil
How We Picked
We focused on four factors: D3 dosage (most adults need 2,000-5,000 IU daily), K2 form (MK-7 is the most bioavailable and longest-acting), fat-soluble delivery (D3 and K2 absorb best with dietary fat), and third-party testing or certification. We excluded products using the inferior MK-4 form of K2, which has a much shorter half-life and requires higher doses.
A. Sports Research Vitamin D3 + K2 — Best Overall
Sports Research Vitamin D3 + K2
Sports Research
- 5,000 IU D3 + 100mcg MK-7 K2 per softgel
- Plant-based K2 (MenaQ7) with coconut MCT oil for absorption
- Vegan Certified, non-GMO, gluten-free, soy-free
- 120 softgels per bottle (4-month supply)
- 52,000+ Amazon reviews with 4.7-star average
Why we picked it: The most popular D3+K2 on Amazon for a reason — it uses the clinically studied MenaQ7 form of K2 (MK-7), pairs it with coconut MCT oil for fat-soluble absorption, and delivers a 4-month supply per bottle. The vegan certification and third-party testing make it a safe default for anyone adding D3+K2 to their stack.
B. Thorne Vitamin D + K2 Liquid — Best Premium
Thorne Vitamin D + K2 Liquid
Thorne
- Liquid drops with metered dispenser for precise dosing
- D3 + K2 in a single drop — adjustable 1-5 drops/day
- 600 servings per bottle (exceptional value per serving)
- Hypoallergenic — no gluten, dairy, soy, or artificial preservatives
- NSF Certified for Sport — trusted by professional athletes
Why we picked it: Thorne's liquid format gives you precise dose control — take 1 drop for maintenance or 3-5 for deficiency correction. At 600 servings per bottle, the per-dose cost is actually lower than most capsules. The NSF Certified for Sport status means it's screened for over 270 banned substances.
C. NatureWise Vitamin D3 5000 IU — Best Value
NatureWise Vitamin D3 5000 IU
NatureWise
- 5,000 IU vitamin D3 per softgel in organic olive oil
- Non-GMO verified, gluten-free, no artificial additives
- 360 softgels per bottle (full year supply)
- America's #1 best-selling vitamin D supplement
- Third-party tested for purity and potency
Why we picked it: If you already get K2 from your diet (fermented foods, aged cheese, natto) or a separate supplement, this standalone D3 gives you a full year of daily doses The olive oil base supports absorption, and NatureWise's third-party testing provides quality assurance at a budget price.
Quick Comparison
| Product | Key Feature | Best For |
|---|---|---|
| Sports Research | 5,000 IU D3 + 100mcg MK-7 K2 per softgel | Best Overall |
| Thorne | Liquid drops with metered dispenser for precise do | Best Premium |
| NatureWise | 5,000 IU vitamin D3 per softgel in organic olive o | Best Value |
Why D3 and K2 Together?
Vitamin D3 increases calcium absorption from your gut, but without adequate K2, that calcium can end up deposited in your arteries instead of your bones. K2 activates osteocalcin (which directs calcium into bones) and matrix GLA protein (which prevents arterial calcification). Taking them together ensures calcium goes where it should.
Most adults are deficient in both — D3 because of limited sun exposure and sunscreen use, and K2 because modern diets lack fermented foods. A combined supplement is the simplest way to cover both bases.
Dosing guidance: 2,000-5,000 IU of D3 daily is appropriate for most adults, paired with at least 100mcg of MK-7 K2. If you haven't had your 25(OH)D levels tested, 2,000 IU is a conservative starting point. Those with confirmed deficiency may need 5,000-10,000 IU under medical supervision.
Related reading: See our guides to supplements for osteoporosis and best omega-3 supplements.
Bottom Line: Which Should You Buy?
For most people: the Our Top 3 Picks at a Glance. Best Overall: Sports Research Vitamin D3 + K2 — 5,000 iu d3 + 100mcg mk-7 k2 per softgel.
On a budget: the Thorne Vitamin D + K2 Liquid. Liquid drops with metered dispenser for precise dosing.
Premium pick: the NatureWise Vitamin D3 5000 IU. 5,000 IU vitamin D3 per softgel in organic olive oil.
Ready to buy?
Jump straight to our top picks on Amazon.
Frequently Asked Questions
Can I take vitamin D3 without K2?
You can, but it's not ideal. D3 increases calcium absorption, and without K2, that calcium may deposit in arteries rather than bones. If you eat fermented foods regularly, you may get enough K2 from diet. Otherwise, a combined D3+K2 supplement is the safer approach.
What time of day should I take D3 K2?
Take D3+K2 with your largest meal that contains fat, since both vitamins are fat-soluble. Morning or afternoon is slightly better than evening — some people report D3 interfering with sleep if taken late at night, though evidence is mixed.
How much vitamin D3 should I take daily?
Most adults benefit from 2,000-5,000 IU daily. The Endocrine Society suggests up to 4,000 IU for adults at risk of deficiency. Get your 25(OH)D blood level tested — optimal range is 40-60 ng/mL. Adjust your dose accordingly.
Is MK-7 or MK-4 better for K2?
MK-7 is preferred for supplementation because it has a much longer half-life (72 hours vs. 1-2 hours for MK-4), meaning a single daily dose maintains stable blood levels. MK-4 requires multiple large doses throughout the day to be effective.
