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Vitamin D3 + K2: Complete Product Guide

Last updated on Feb 12, 2026

Vitamin D3 + K2: Complete Product Guide

What is Vitamin D3 + K2?

Vitamin D3 and K2 are two essential vitamins that work synergistically together. Vitamin D3 (cholecalciferol) is the most bioavailable form of vitamin D, while Vitamin K2 (menaquinone) helps direct calcium to where it's needed. Together, they're more effective than either vitamin alone.

Key Benefits

Bone Health

  • Vitamin D3 helps your body absorb calcium from food
  • Vitamin K2 activates proteins that direct calcium into bones
  • Together they support strong, healthy bones
  • May help reduce risk of osteoporosis

Cardiovascular Health

  • K2 helps prevent calcium buildup in arteries
  • Supports healthy blood vessel function
  • Promotes cardiovascular wellness
  • May help maintain healthy blood pressure

Immune System Support

  • Vitamin D3 is crucial for immune function
  • Supports the body's natural defense mechanisms
  • Helps regulate immune response
  • Particularly important during winter months

Mood & Mental Health

  • Vitamin D3 supports healthy mood
  • May help with seasonal mood changes
  • Supports cognitive function
  • Important for overall mental wellness

Dental Health

  • Supports strong, healthy teeth
  • Works with calcium for optimal dental health

How to Take Vitamin D3 + K2

Recommended Dosage:

  • Check your bottle label for specific dosage
  • Common dosages: 5,000 IU D3 + 100-200mcg K2 daily
  • Some formulations offer higher doses

Best Time to Take:

  • Take with a meal containing fat - Both D3 and K2 are fat-soluble vitamins
  • Morning or afternoon with breakfast or lunch is ideal
  • Can be taken at any time of day, but consistency matters most

Why Fat Matters: Since both vitamins are fat-soluble, taking them with dietary fat significantly improves absorption. Include foods like:

  • Avocado
  • Nuts or nut butter
  • Eggs
  • Olive oil
  • Full-fat dairy
  • Fish

When to Expect Results

  • Bone health: Benefits develop over months of consistent use
  • Immune support: May notice fewer colds/infections over the winter season
  • Mood improvements: Some people notice changes within 2-4 weeks
  • Optimal levels: Takes 2-3 months to build adequate vitamin D stores
  • Cardiovascular benefits: Develop gradually with long-term use

Blood testing: Ask your doctor to check your vitamin D levels (25-hydroxyvitamin D) to ensure you're in the optimal range (typically 40-60 ng/mL).

Who Should Consider Vitamin D3 + K2?

You may benefit if you:

  • Live in northern climates (limited sun exposure)
  • Spend most time indoors
  • Have darker skin (requires more sun for D3 production)
  • Are over 50 (natural D3 production declines)
  • Are concerned about bone health
  • Have been diagnosed with vitamin D deficiency
  • Want to support immune function
  • Are taking calcium supplements (K2 helps direct it properly)

Important: Vitamin D deficiency is extremely common, affecting up to 40% of Americans.

Drug Interactions - Important!

Consult your doctor before taking if you:

  • Take blood thinners (warfarin/Coumadin) - K2 can affect clotting
  • Take calcium channel blockers
  • Have kidney disease or kidney stones
  • Have a condition causing high calcium levels
  • Are pregnant or nursing
  • Take medications that affect vitamin D metabolism

Potential Side Effects

When taken at recommended doses, Vitamin D3 + K2 is very safe. Excessive vitamin D (very high doses over long periods) can cause:

  • High calcium levels in blood
  • Nausea
  • Weakness
  • Kidney problems

At recommended doses: Side effects are extremely rare.

Vitamin K2 note: The K2 form (MK-7) used in supplements doesn't interfere with blood clotting like K1 does, but those on blood thinners should still consult their doctor.

Tips for Best Results

  1. Take with fat - This is crucial for absorption
  2. Be consistent - Daily supplementation is important
  3. Get your levels tested - Ask your doctor to check vitamin D levels
  4. Don't megadose - More isn't always better; stick to recommended amounts
  5. Consider sunlight - Safe sun exposure is still beneficial
  6. Monitor calcium intake - Ensure adequate calcium for D3 and K2 to work with

Why Combine D3 and K2?

The synergistic effect:

  • Vitamin D3 alone: Increases calcium absorption but doesn't direct where it goes
  • Vitamin K2 alone: Activates proteins that direct calcium but needs adequate D3
  • Together: D3 ensures calcium absorption, K2 ensures it goes to bones (not arteries)

This combination is more effective than taking D3 alone and helps prevent calcium from depositing in arteries while ensuring it reaches your bones.

Forms of K2

MK-7 (Menaquinone-7):

  • Longer half-life (stays in body longer)
  • Most common in supplements
  • Derived from fermented soybeans (natto)
  • Effective at lower doses

MK-4 (Menaquinone-4):

  • Shorter half-life
  • Requires higher, more frequent doses
  • Some research supports cardiovascular benefits

Our formula uses the form shown on your bottle label for optimal effectiveness.

Vitamin D Testing

Optimal vitamin D levels:

  • Deficient: Below 20 ng/mL
  • Insufficient: 20-30 ng/mL
  • Sufficient: 30-50 ng/mL
  • Optimal: 40-60 ng/mL
  • High: Above 80 ng/mL

Ask your doctor for a 25-hydroxyvitamin D blood test to check your levels.

Storage

  • Store in a cool, dry place away from direct sunlight
  • Keep bottle tightly closed
  • Do not store in humid environments like bathrooms
  • Check expiration date on bottle

Quality & Testing

All Luma Nutrition Vitamin D3 + K2 is:

  • Third-party tested for purity and potency
  • Manufactured in the USA in GMP and FDA certified facilities
  • NSF certified
  • Free from contaminants and heavy metals
  • Uses bioavailable forms (D3, not D2; K2, not K1)

You can request a Certificate of Analysis (COA) by emailing help@lumanutrition.com with your bottle's lot number.

Frequently Asked Questions

Why not just get vitamin D from the sun? While sun exposure is beneficial, many factors limit D3 production: latitude, season, time of day, skin tone, age, and sunscreen use. Most people don't get adequate sun exposure year-round, especially in winter.

Can I take too much vitamin D? Yes, but it's difficult with normal supplementation. Toxicity typically occurs with doses above 10,000 IU daily for extended periods. Recommended doses (1,000-5,000 IU) are very safe.

Do I need K2 if I'm not taking calcium supplements? Yes! Your body uses calcium from food, and K2 helps direct it properly regardless of whether you take calcium supplements.

What's the difference between D2 and D3? D3 (cholecalciferol) is more potent and raises blood levels more effectively than D2 (ergocalciferol). D3 is the superior form and what we use.

Can I take this with other supplements? Yes, Vitamin D3 + K2 combines well with most supplements. It's often taken alongside calcium, magnesium, and omega-3s for comprehensive bone and cardiovascular support.

Should I take this year-round or just in winter? Year-round supplementation is typically recommended, as most people don't get adequate sun exposure even in summer due to indoor lifestyles, sunscreen use, and other factors.

How is K2 different from K1? K1 (found in leafy greens) is important for blood clotting. K2 (in our supplement) activates proteins that regulate calcium deposition and supports bone and cardiovascular health. They have different functions.

Calcium and Vitamin D3 + K2

If you take calcium supplements:

  • D3 + K2 makes calcium supplementation more effective and safer
  • D3 ensures calcium absorption
  • K2 directs calcium to bones (not arteries)
  • This combination is ideal for bone health

If you don't take calcium supplements:

  • You still benefit from D3 + K2
  • They help your body use dietary calcium more effectively
  • K2 prevents calcium from dietary sources from depositing in arteries

Special Populations

Older Adults:

  • Especially important as D3 production declines with age
  • Helps maintain bone density
  • Supports immune function
  • May help prevent falls (D3 supports muscle strength)

People with Dark Skin:

  • Melanin reduces D3 production from sunlight
  • May need higher supplementation
  • Particularly important in northern climates

Indoor Workers:

  • Limited sun exposure increases deficiency risk
  • Year-round supplementation recommended

Need More Information?

  • Check the detailed label on your bottle
  • Visit the Vitamin D3 + K2 product page on lumanutrition.com
  • Contact our support team at help@lumanutrition.com
  • Request a Certificate of Analysis for detailed testing results
  • Ask your healthcare provider to test your vitamin D levels

Our Guarantee

Try Vitamin D3 + K2 risk-free with our 90-day money-back guarantee. If it doesn't work for you, return it for a full refund - even if the bottle is empty.

The Bottom Line

Vitamin D3 + K2 is one of the most important supplement combinations for overall health. With widespread vitamin D deficiency and the synergistic benefits of combining D3 with K2, this is a foundational supplement that supports bone health, cardiovascular wellness, immune function, and much more. Consider it an insurance policy for optimal health, especially during winter months or if you spend most of your time indoors.