Vitamins D and K and calcium metabolism
Nutrition reviews describe vitamin D3 and K2 as synergistic partners — D3 increases calcium absorption while K2 activates proteins that direct calcium deposition to bone and away from vasculature.
About this product
Suggested use
About monthlees
The supplement industry is built on inflated pricing, confusing labels, and aggressive marketing.
Monthlees exists to fix that.
We believe:
- Supplements should be clinically dosed
- Pricing should be transparent
- Testing should be independent
- And customers shouldn't pay for influencer commissions or retail margins
Instead of hiding costs inside the product price, we use a simple membership model — so you pay what supplements actually cost to make.
Shipping & returns
• Shipping: Orders are processed within 1–2 business days. Standard delivery takes 3–7 business days depending on your location.
• Returns: You may return or exchange products within 30 days of receiving your order. Items must be in original condition with proof of purchase.
If your item is defective or damaged due to manufacturing issues, we’ll gladly replace it at no additional cost.
30 Day Money Back Guarantee
FDA Disclaimer
What's in CardioCal™?
- 210 mg calcium (16% DV)
- 125 mcg vitamin D3 (625% DV)
- 100 mcg vitamin K2 MK-7
- 5 mg BioPerine® black pepper extract
- 1 veggie capsule per serving
- 60 capsules per bottle
Supplement Facts
CardioCal™
Supplement Facts
Serving Size 1 Veggie Capsule
Servings Per Container 60
Amount Per Serving
% DV
Calcium (as Calcium Carbonate)
210 mg
16%
Vitamin D3 (Cholecalciferol)
125 mcg
625%
Vitamin K2 (mk-7) (as Menaquinone)
100 mcg
†
BioPerine® (Black Pepper Fruit Extract)
5 mg
†
Other Ingredients: Microcrystalline cellulose, hypromellose (vegetable capsule).
Free of
- D3 without K2
- Uncoordinated calcium stacks
- Proprietary vitamin blends
Diet friendly
- D3 + K2 MK-7 paired
- Calcium carbonate disclosed
- BioPerine® absorption support
- Vegetable capsules
Support skeletal strength and cardiovascular health
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Bone mineral support
210 mg calcium with vitamin D3 supports calcium absorption and bone mineralization for structural strength.*
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Healthy calcium utilization
Vitamin K2 (MK-7) helps direct calcium to bones while supporting vascular balance — the pairing D3-only supplements often miss.*
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Cardiovascular integrity
Matrix Gla-protein activation supports normal arterial function and circulatory wellness as part of coordinated calcium metabolism.*
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BioPerine® absorption
5 mg BioPerine® black pepper fruit extract supports bioavailability of fat-soluble vitamins — disclosed on every label.*
How it works
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Step 1: Absorb
Vitamin D3 supports intestinal calcium absorption and helps maintain normal serum calcium levels — 125 mcg per capsule as listed on the supplement facts panel.
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Step 2: Direct
Vitamin K2 (MK-7) activates proteins such as osteocalcin and matrix Gla-protein — helping direct calcium toward bones and away from arterial tissues.*
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Step 3: Support
This coordinated D3 + K2 + calcium pairing supports bone mineral density and vascular integrity — with BioPerine® for nutrient absorption.*
Supplement facts
D3 + K2 calcium synergy — smart calcium for strong bones.
Calcium (as Calcium Carbonate)
—
210 mg
16%
** Percent Daily Values are based on a 2,000 calorie diet.
Vitamin D3 (Cholecalciferol)
—
125 mcg
625%
** Percent Daily Values are based on a 2,000 calorie diet.
Vitamin K2 (mk-7) (as Menaquinone)
—
100 mcg
†
† Daily Value not established. Consult your provider if taking anticoagulant medications.
BioPerine® (Black Pepper Fruit Extract)
—
5 mg
†
† Daily Value not established. BioPerine® is a registered trademark of Sabinsa Corporation.
Evidence-based ingredients
The science behind the ingredients
CardioCal™ discloses calcium, D3, K2 (MK-7), and BioPerine® on every label — not a mystery vitamin stack. Explore the research on calcium metabolism, bone health, and cardiovascular support.*
125 mcg
Vitamin D3
100 mcg
Vitamin K2 MK-7
60
Capsules per bottle
Menaquinone-7 and cardiovascular health
Reviews of MK-7 supplementation discuss its role in activating matrix Gla-protein — supporting arterial elasticity and cardiovascular integrity as part of calcium metabolism.
Vitamin D and bone mineral density
Controlled trials report that vitamin D3 supplementation supports calcium absorption and bone mineral density in adults with suboptimal vitamin D status.
Piperine and nutrient bioavailability
Pharmacology reviews describe piperine from black pepper as enhancing bioavailability of fat-soluble vitamins and other nutrients through absorption pathway modulation.
Compare D3 + K2 formulas
How Monthlees CardioCal™ stacks up
Many calcium and D3 products skip K2 entirely — leaving calcium direction unaddressed. CardioCal pairs D3, K2 MK-7, calcium, and BioPerine® in one transparent capsule.
Typical D3 supplement |
||
|---|---|---|
|
Vitamin K2 included
|
100 mcg MK-7 on label
|
Often omitted
|
|
Vitamin D3 dose
|
125 mcg (625% DV)
|
Often 25–50 mcg
|
|
Calcium + absorption support
|
210 mg + BioPerine®
|
Often D3 only
|
|
Member pricing available
|
Yes — Monthlees members
|
No
|
Insider access to the world's best labs & supplement manufacturers.
Membership allows us to sell products for a fraction of the typical industry retail price. Think of it as an insider access pass to the warehouses of the supplement industry.
Monthlees members don't pay for:
- Middlemen
- Marketing & influencer costs
- Retailer markups
- Distributor margins
Stop overpaying for incomplete D3 stacks.
Buying separate D3, K2, and calcium bottles often costs $40–$70/month with inconsistent dosing. CardioCal™ and Monthlees membership keep coordinated bone and cardiovascular support affordable.
| Treatment | Other guys | Monthlees |
|---|---|---|
| CardioCal™ monthly supply 60 capsules — 1 capsule daily | $47.00 | $19.21 |
| Separate D3 + K2 bottles Retail-priced vitamin stack | $40–$70/mo | All-in-one formula |
| D3 without K2 Incomplete calcium pairing | Missing K2 MK-7 | 100 mcg on label |
Start your monthlees health journey with complete support
Your membership gives you access to better pricing, personalized guidance, and everything you need to build a healthy supplement & personal care routine that effortlessly fits your life.
- Unlock member pricing of 50-80% off on every product
- Get your personalized Starter Routine Kit
- Use flexible subscriptions to save on repeat orders
- Manage everything easily from your Monthlees account
- 30-day money back guarantee on all product purchases
- Automatic savings applied at checkout
- 100% flexible. Update, pause, or cancel anytime
Member trust
Confidence built into every order
From clear member pricing to flexible subscriptions and responsible product standards, Monthlees is built to help you shop with confidence — without inflated markups, hidden tiers, or checkout surprises.
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Transparent product pricing
Every product shows clear pricing for guests and members, so you can compare your savings before you buy.
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Member savings applied automatically
When you’re signed in as a member, your eligible discounts are applied automatically at checkout.
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Subscriptions that stay flexible. Cancel anytime.
Start, pause, skip, or adjust product subscriptions from your account — without hidden hoops or confusing rules.
Frequently asked questions
Everything you need to know about Monthlees member pricing, subscriptions, and how checkout works.
Why pair vitamin D3 with vitamin K2?
Vitamin D3 increases calcium absorption, while vitamin K2 activates proteins that help direct calcium to bones and away from soft tissues. CardioCal delivers 125 mcg D3 and 100 mcg K2 (MK-7) per capsule — the pairing recommended by longevity-focused nutrition research.
Can I take CardioCal with blood thinners?
Consult your healthcare provider before use if you take warfarin or other anticoagulant medications. Vitamin K2 can interact with blood-thinning drugs by affecting vitamin K-dependent clotting factors.
How is this different from taking D3 alone?
D3 alone increases calcium absorption but does not direct where calcium is deposited. K2 (MK-7) complements D3 by activating osteocalcin and matrix Gla-protein. CardioCal also includes 210 mg calcium and BioPerine® in one daily capsule.
Why I created monthlees...
When I was 19 years old, I was diagnosed with a brain tumor. That experience forced me to start asking deeper questions about how the human body actually works.
Over the next 18 months, I immersed myself in studying health, nutrition, and neuroscience — eventually earning my degree in Neuroscience from Duke University. Along the way, I discovered something powerful: the body is incredibly resilient & inherently self-healing when it’s given the right support.
Strategic nutrition and supplementation became a major part of my own health journey. And over the last two decades, I’ve devoted my life to helping millions of people around the world take a more proactive role in their health.
That experience completely changed how I thought about health — and ultimately shaped the way Monthlees was built.
I created Monthlees because I was tired of seeing people pay premium prices for supplements that were under-dosed, over-marketed, and difficult to trust.
My goal is simple: build the kind of brand I would want for myself and my family — with better ingredients, transparent formulas, meaningful dosages, and a business model built on long-term trust.
— Chris Walker, Founder of Monthlees
