Vitamin D works more like a hormone than a vitamin, central to how the body runs,* and most people are low on it without ever knowing. Modern healthcare waits for you to get sick. D3X starts before that. One nutrient, done right, by a company that exists for nothing else.

Shop Why D3X
5.0  ·  11 reviews
D3X Vitamin D3 + K2 liquid supplement
2000 IU · D3 + K2 MADE IN USA
Made in USA
Third-Party Tested
cGMP Facility
3 Ingredients
No Sweeteners
Olive Oil Base
Made in USA
Third-Party Tested
cGMP Facility
3 Ingredients
No Sweeteners
Olive Oil Base

A gap hiding
in plain sight

Low Vitamin D status is the most widespread nutritional gap worldwide,2 yet it slips past most people unnoticed. It rarely gets tested, rarely gets talked about, and almost never gets fixed properly. That gap is the whole reason D3X exists.

01
Why it happens
Indoor lifestyles, poor diets, seasons, geography, sunscreen use, and inconsistent sun exposure.
02
Why it's missed
Vitamin D isn't routinely tested for, so many don't connect their symptoms to being low.
03
Why it matters
Vitamin D acts more like a hormone than a vitamin, influencing gene-related processes throughout the body.2 It plays a key role in helping your body function the way it's supposed to.*
Read the science →

Four things
that actually
matter

Vitamin D works like a baseline the whole body runs on. Get the baseline right, and it shows up across the things you actually notice.*

Sleep
Supports better recovery and more consistent sleep quality over time.6*
Mood
Supports brain health pathways tied to mood and baseline wellbeing.7*
Performance
Supports muscle function, recovery, and physical performance.8*
Focus
Supports neurological function related to clarity and concentration.9*
See the research →

Three things
set us apart

Plenty of brands sell vitamin D. Almost none are built for it. Three things make D3X different: what we choose to be, what goes in the bottle, and what happens after it arrives.

01
What we make
One product, done right. Vitamin D isn't a side project here, it's the entire company. That focus means every decision, every dollar, every detail goes into getting one nutrient right.
02
What's in the bottle
Three ingredients, nothing to hide. D3, K2 as MK-7, and an organic olive oil base. No seed oils, no fillers, no sweeteners, no proprietary blends. The cheap stuff cuts corners you can't see. We didn't.
03
After you buy
Most brands' work ends at checkout. Ours starts there: a fold-out guide in every box, reminders, and a subscription paced to the habit. A bottle in the cupboard does nothing.
More on why D3X →

Only three
simple
ingredients

No dyes. No sweeteners. No proprietary blends. No fillers. Just the three things that matter.

01
Vitamin D3
The main event

The star of D3X. It behaves more like a hormone than a typical vitamin and influences a wide range of processes in the body.2* We use D3 because it's the form your body naturally makes from sunlight, and it's generally more effective than D2 at raising and maintaining Vitamin D levels.3*

2000 IU per serving · As cholecalciferol
02
Vitamin K2
Directs the calcium

The ingredient that finishes the job. D3 helps your body absorb calcium; K2 helps direct where that calcium goes, supporting proper distribution and balance.5* We chose MK-7 because it stays active longer than other forms,4 making it a better fit for consistent daily use.

100 mcg · MK-7 (Menaquinone-7)
03
Organic Olive Oil
Makes it absorb

Vitamin D is fat-soluble, so it absorbs best with fat. We use olive oil as a clean, food-based carrier that's naturally rich in antioxidants. A better choice than processed oils or fillers.

Certified Organic · Cold-pressed
That's it.  ·  No artificial anything
More on the ingredients →
D3X bottle on a bathroom counter

A habit that
actually sticks

01
1 mL, once a day
Drop it into your coffee, shake, food, or straight under your tongue. Three seconds, works the same either way.
02
Same time, every day
Pick a moment you already hit, morning coffee, pre-workout, breakfast, and anchor it there.
03
Keep it going
Consistency is where D3X actually works. The 3-month plan ships automatically, so staying consistent isn't something you have to think about.
Why daily matters →

Five hyped.
One that matters

The supplement aisle runs on hype: trendy blends with big claims and bigger price tags, most of them barely studied. Vitamin D is the opposite, one of the most researched nutrients there is, and most people are low on it. No one can patent it, so no one spends millions telling you to take it. We think that's exactly why it gets skipped.

The hype shelf
  • Green powders~$80/mo
  • Greens gummies~$80/mo
  • Premium probiotics~$80/mo
  • Nootropics~$80/mo
  • Electrolytes~$50/mo
Big claims. Light evidence. Stacked up, $300+ a month.
The foundation
D3X
Liquid Vitamin D3 + K2
75¢/ day
$22.40 / bottle on the 3-month plan
  • One of the most studied nutrients in science
  • The gap ~70% of Americans actually have1
  • Three ingredients, third-party tested, made in USA
Skip the trend of the month. Cover the gap that's real.
Start the habit

No hype.
Just research.

01
Research
What a Four-Year Vitamin D Trial Found About Aging
→
02
Research
Vitamin D And Sleep: What The Research Shows
→
03
Research
Why Vitamin D Needs Fat To Be Absorbed
→
The Science →

Questions
worth asking

What is D3X?
D3X is a premium liquid Vitamin D3 + K2 supplement made with three ingredients (Vitamin D3, Vitamin K2 as MK-7, and organic olive oil), packaged in a glass bottle with a 1 mL dropper. Each bottle contains 30 daily servings of 2000 IU Vitamin D3 and 100 mcg Vitamin K2. Made in the USA in a cGMP facility and third-party tested.
How is D3X different from other Vitamin D supplements?
Three things set D3X apart. First, what's in the bottle: an olive oil base, a glass bottle, three ingredients, with no seed oils, fillers, sweeteners, or proprietary blends. Second, what we make: one product. Vitamin D is the entire company, not a line item among hundreds. Third, what happens after you buy: an educational pamphlet in every box, daily ritual messaging, and a subscription cadence built around the habit.
How common is Vitamin D insufficiency?
Vitamin D insufficiency is widespread, especially among people who get limited sunlight, live in urban areas, or spend most of their time indoors.2 Even with a healthy diet, many individuals may not get enough Vitamin D from food or sun exposure alone.* D3X focuses on daily consistency to help fill common nutritional gaps.*
What is Vitamin D and what does it do?
Vitamin D is a fat-soluble nutrient that supports various functions in the body.* It plays a role in maintaining normal muscle function, immune system support, and overall wellness.2* Vitamin D also interacts with receptors throughout the body, which is why it's often discussed in relation to energy, mood, and daily performance.* D3X is formulated to make Vitamin D intake simple and consistent, especially for individuals with limited sun exposure or indoor lifestyles.*
What are common signs of low Vitamin D?
Low Vitamin D levels may be associated with general fatigue, reduced motivation, or changes in mood or focus in some individuals.* These experiences are nonspecific and can result from a variety of factors. It's important to talk to a healthcare provider to better understand your individual health needs.
Can you get enough Vitamin D from sunlight alone?
Sunlight is a natural source of Vitamin D3, produced by the skin in response to UVB exposure.* However, factors like time of day, season, skin tone, geographic location, clothing, sunscreen use, and time spent indoors can limit how much Vitamin D your body produces.10* Many people use supplements like D3X to support their Vitamin D levels consistently throughout the year.*
How is D3X different from a multivitamin?
Multivitamins spread small amounts across dozens of ingredients. D3X focuses on the one thing most people are actually missing, in a liquid format built for daily consistency, not pill fatigue.

Sources

Every health claim on this page is backed by peer-reviewed research. Expand to read the original studies.

Sources & references 11
  1. 1
    Vitamin D deficiency and insufficiency among US adults: prevalence, predictors and clinical implications
    British Journal of Nutrition · 2018
    View study →
  2. 2
    Vitamin D Deficiency
    Holick MF · New England Journal of Medicine · 2007
    View study →
  3. 3
    Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis
    Tripkovic et al. · American Journal of Clinical Nutrition · 2012
    View study →
  4. 4
    MK-7 and Its Effects on Bone Quality and Strength
    Sato et al. · Nutrients · 2020
    View study →
  5. 5
    Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study
    Geleijnse et al. · Journal of Nutrition · 2004
    View study →
  6. 6
    Vitamin D Supplementation and Sleep: A Systematic Review and Meta-Analysis of Intervention Studies
    Abboud · Nutrients · 2022
    View study →
  7. 7
    The effect of vitamin D supplementation on depression: a systematic review and dose-response meta-analysis of randomized controlled trials
    Mikulska et al. · 2024 · 31 trials, 24,189 participants
    View study →
  8. 8
    Effect of vitamin D supplementation on upper and lower limb muscle strength and muscle power in athletes: A meta-analysis
    Zhang et al. · PLOS ONE · 2019
    View study →
  9. 9
    A Systematic Review and Meta-Analysis of The Effect of Low Vitamin D on Cognition
    Goodwill & Szoeke · Journal of the American Geriatrics Society · 2017
    View study →
  10. 10
    Sunlight and Vitamin D: A global perspective for health
    Wacker & Holick · Dermato-Endocrinology · 2013
    View study →
  11. 11
    What do we know about spending related to public health in the U.S. and comparable countries?
    Peterson-KFF Health System Tracker · 2020
    View source →

Time to
get serious
about your D.

Three ingredients. One daily habit. Free shipping, cancel anytime, and $8.80 off every bottle on the 3-month plan.

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