Best Vitamin D Supplements of 2025: D3, D3+K2 & Dosage Guide
We evaluated the top vitamin D supplements based on form (D3 vs D2), dosage, bioavailability, third-party testing, and additional nutrients like vitamin K2. Vitamin D is crucial for bone health, immune function, and overall wellness, yet deficiency is widespread.
Why Vitamin D3? We focus on D3 (cholecalciferol) rather than D2 (ergocalciferol) because research shows D3 is more effective at raising and maintaining blood levels of vitamin D. Our rankings prioritize products with D3, transparent testing, and appropriate dosing.
Quick Comparison
| Rank | Product | Type | Dosage | Rating | Price | Action |
|---|---|---|---|---|---|---|
| #1 | Thorne Vitamin D-5,000 | Vitamin D3 (Cholecalciferol) | 5,000 IU per capsule | ★4.8/5 | $15-18 (90 capsules) | View on Amazon |
| #2 | Sports Research Vitamin D3 + K2 | D3 + K2 MK-7 Combination | 5,000 IU D3 + 100mcg K2 | ★4.7/5 | $20-25 (60 softgels) | View on Amazon |
| #3 | NOW Foods Vitamin D-3 10,000 IU | High-Dose Vitamin D3 | 10,000 IU per softgel | ★4.6/5 | $10-12 (120 softgels) | View on Amazon |
| #4 | Garden of Life mykind Organics Vegan D3 | Vegan D3 from Lichen | 2,000 IU per tablet | ★4.5/5 | $18-22 (60 tablets) | View on Amazon |
| #5 | Nordic Naturals Vitamin D3 Gummies | Vitamin D3 Gummy | 1,000 IU per gummy | ★4.4/5 | $15-18 (60 gummies) | View on Amazon |
| #6 | Vitafusion Vitamin D3 Gummies | Budget Vitamin D3 Gummy | 2,000 IU per 2 gummies | ★4.3/5 | $8-10 (75 gummies) | View on Amazon |
Detailed Reviews
Thorne Vitamin D-5,000
Pros
- • NSF Certified for Sport
- • Pure D3 without unnecessary additives
- • Third-party tested for potency and purity
- • Trusted by healthcare practitioners
- • Easy-to-swallow capsules
Cons
- • Higher price per serving
- • No added vitamin K2
- • Limited dosage options
Key Features
Sports Research Vitamin D3 + K2
Pros
- • Includes K2 MK-7 for optimal calcium absorption
- • Coconut oil base for enhanced absorption
- • Non-GMO and third-party tested
- • Affordable combination product
- • Easy-to-swallow softgels
Cons
- • Contains coconut oil (allergen for some)
- • Softgels may be too large for some users
- • Limited K2 dosage compared to standalone products
Key Features
NOW Foods Vitamin D-3 10,000 IU
Pros
- • High potency for severe deficiency
- • Excellent value for money
- • GMP quality assured
- • Widely available
- • Trusted brand with decades of reputation
Cons
- • Very high dose (requires medical supervision)
- • No vitamin K2 included
- • Not suitable for daily maintenance in most people
Key Features
Garden of Life mykind Organics Vegan D3
Pros
- • Vegan D3 sourced from lichen
- • USDA Organic and Non-GMO verified
- • Includes whole food blend
- • No synthetic additives
- • Gentle on the stomach
Cons
- • Lower potency (2,000 IU)
- • Higher cost per IU
- • May require multiple tablets for deficiency
Key Features
Nordic Naturals Vitamin D3 Gummies
Pros
- • Great taste (wild berry flavor)
- • Easy for those who dislike pills
- • Third-party tested
- • No artificial colors or flavors
- • Good for children and adults
Cons
- • Lower dose (requires 2-5 gummies for optimal intake)
- • Contains sugar (2g per gummy)
- • More expensive per IU
Key Features
Vitafusion Vitamin D3 Gummies
Pros
- • Very affordable
- • Pleasant peach and berry flavor
- • Widely available
- • No gluten or dairy
- • Good compliance for those who dislike pills
Cons
- • Contains added sugars and corn syrup
- • Artificial flavors and colors
- • Not third-party tested
- • Less suitable for serious deficiency
Key Features
Vitamin D Dosage Guide
Recommended Daily Intake
- Infants (0-12 months): 400 IU (10 mcg)
- Children (1-18 years): 600 IU (15 mcg)
- Adults (19-70 years): 600 IU (15 mcg)
- Adults (71+ years): 800 IU (20 mcg)
- Pregnant/Breastfeeding: 600 IU (15 mcg)
Note: Many healthcare providers recommend higher doses (1,000-2,000 IU daily) for maintenance, especially for individuals with limited sun exposure or darker skin tones.
Understanding Vitamin D Levels
- Deficient: Less than 20 ng/mL (50 nmol/L) - requires medical treatment
- Insufficient: 20-29 ng/mL (50-74 nmol/L) - may benefit from supplementation
- Sufficient: 30-50 ng/mL (75-125 nmol/L) - optimal range
- High: Above 50 ng/mL (125 nmol/L) - monitor to avoid toxicity
Should You Take D3 with K2?
Vitamin K2 works synergistically with vitamin D by directing calcium to bones and teeth rather than soft tissues. If you take higher doses of vitamin D (above 4,000 IU), consider a D3+K2 combination to support cardiovascular and bone health.
Best Time to Take Vitamin D
Take vitamin D with a meal containing fat for optimal absorption, as it is a fat-soluble vitamin. Morning or early afternoon is ideal, as some evidence suggests evening doses may interfere with sleep.
Disclaimer: As an Amazon Associate, we earn from qualifying purchases. The information provided is for educational purposes only and is not medical advice. Vitamin D supplementation should be based on individual needs and blood test results. Consult a healthcare provider before starting any supplement regimen, especially if taking medications or managing health conditions.