D3 + K2 (Plant Based) - Sports Research

Product: 125 mcg (5000 IU) D3 + 100 mcg K2 per capsule | 60 Plantgel Capsules Brand: Sports Research Primary Use: Bone health, calcium metabolism, immune support, cardiovascular health

Form & Bioavailability

Vitamin D3: Cholecalciferol (plant-based from lichen) Vitamin K2: MK-7 form (most bioavailable K2) Delivery: Plantgel capsule with coconut oil (fat-soluble vitamins need fat)

K2 Form | Half-life | Bioavailability

---------|-----------|-----------------

MK-7 | ~3 days | Highest, reaches all tissues

MK-4 | ~1-2 hours | Shorter acting, needs multiple doses

MK-7 is the preferred form—longer half-life means once-daily dosing works.

The D3 + K2 Synergy

Why combine them:

• Vitamin D increases calcium absorption from gut
• Without K2, calcium can deposit in arteries (calcification)
• K2 activates proteins (osteocalcin, MGP) that direct calcium to bones and away from soft tissues
• Together: calcium goes where it's needed (bones), not where it causes harm (arteries)

Dosing

Vitamin D3:

• RDA: 600-800 IU/day
• Upper limit (NIH): 4000 IU/day
• Common supplement: 1000-5000 IU/day
• This product: 5000 IU (above UL but commonly used)

Vitamin K2:

• No established RDA
• Typical dose: 100-200 mcg MK-7/day
• Ratio guideline: 100 mcg K2 per 5000-10000 IU D3

This product ratio: 5000 IU D3 : 100 mcg K2 = appropriate pairing Timing: With a fat-containing meal (both are fat-soluble)

Safety

Common side effects: Generally well-tolerated Contraindications:

• Vitamin K2: Those on warfarin (vitamin K antagonist) - consult physician
• Vitamin D: Hypercalcemia, certain granulomatous diseases

Key interactions:

• 🔴 Warfarin: K2 counteracts warfarin's mechanism—avoid or carefully manage with physician
• 🟡 Other anticoagulants (DOACs): Less interaction but still use caution
• 🟡 Thiazide diuretics: May increase calcium levels with D3
• 🟢 Magnesium: Synergistic—Mg needed for D3 metabolism

Evidence Quality

Strong evidence for:

• Vitamin D: Bone health, immune function, muscle function
• D3+K2 combination: Improved calcium utilization

Moderate evidence for:

• Cardiovascular calcification prevention (K2)
• Bone density improvement (combination)
• Reduced fracture risk

Preliminary evidence for:

• Mood/depression support (D3)
• Autoimmune disease modulation (D3)

Product Assessment

Positives:

• Plant-based D3 (lichen-sourced) - rare, suitable for vegans
• MK-7 form of K2 (most effective)
• Appropriate D3:K2 ratio
• Coconut oil base for absorption
• Plantgel technology (vegan softgel)
• Third-party tested
• Non-GMO verified

Considerations:

• 5000 IU D3 is above RDA/UL—appropriate for deficiency correction but test levels periodically
• Those on blood thinners must consult physician before K2
• Should combine with magnesium for optimal D3 utilization

Important: Test Your Levels

5000 IU daily is appropriate for:

• Those with documented deficiency
• Dark-skinned individuals
• Those with limited sun exposure
• Overweight/obese individuals (D3 stored in fat)

Optimal blood level: 40-60 ng/mL (25-hydroxyvitamin D)

Get tested every 6-12 months when supplementing with high-dose D3.

Stack Compatibility

Essential pairing:

• Magnesium (needed to convert D3 to active form)

Synergistic:

• Calcium (if dietary intake insufficient)
• Omega-3 (cardiovascular support)

Verdict

Excellent D3+K2 combination with premium forms (plant-based D3, MK-7 K2) and appropriate ratio. The plant-based sourcing makes this one of the few vegan-friendly D3 options. The 5000 IU dose is therapeutic—monitor blood levels periodically and ensure adequate magnesium intake.

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*Research compiled using supplement-researcher methodology*