Vitamin D3 and K2: A Synergistic Team

We are excited to offer you the convenience of two powerhouse vitamins in one supplement! Our new Vitamin D3+K2 contains 5,000 IU vegan D3 from lichen and 100 mcg K2 as all-trans MK-7 per capsule. This allows you to take just 1 capsule per day providing a clinically relevant dose for those who want more support!

The benefits of vitamin D and vitamin K2 are numerous and synergistic. Both vitamins are required for lifelong health, yet many individuals fall short of supplying daily needs.

Vitamin D Essential for Health

Vitamin D is essential at every stage of life. From early neurodevelopment and bone growth to immune system function and lifelong cognitive and mental health, maintaining optimal vitamin D levels is critical for overall well-being.

Vitamin D is required for fertility, sex steroid hormone production, cartilage and joint health, thyroid function, and so much more. All cells in your body use vitamin D, but the highest expression of vitamin D receptors are found in the intestinal tract, which profoundly impacts your gut microbiome and immune system.

A 2025 Vitamin D: Evidence-Based Health Benefits and Recommendations for Population Guidelines study stated, “a daily dose between 4000 and 6000 IU of vitamin D3 to achieve serum 25(OH)D levels between 40 and 70 ng/mL would provide greater protection against many adverse health outcomes.”

At least 25% of the US population has a vitamin D blood level of less than 20 ng/mL. More than 1 billion people worldwide are estimated to be vitamin D deficient. Lack of sun exposure, sunscreen use, various medications, and poor digestion can all contribute to low vitamin D levels.

Vitamin K2 Needed at Every Stage of Life

Vitamin K2 is best known for its role in maintaining calcium homeostasis, working in a check and balance system with vitamin D. K2 is required for the transport of calcium out of the blood stream and deposition into bones. Without this transport activity, calcium either builds up in the bloodstream or deposits unnecessarily elsewhere in the body. Vitamin K is essential at every stage of life.

Vitamin K2 MK-7 has the highest bioavailability over MK-4 and is the preferred supplemental form.

Better Together: Vitamin D and Vitamin K

Vitamin D and vitamin K provide many individual and synergistic benefits. They work together to support cardiovascular health, bone density, longevity, breast health, brain and cognitive health.

Heart and Blood Vessels

Vitamin D and K are required for vascular flexibility and elasticity as they work together to prevent calcium from depositing into blood vessel walls. Blood moves more freely through vessels with less workload on the heart as it contracts with optimal vitamin D and K levels.

In clinical trials with older adult men and women, those who had optimal levels of both vitamin D and K had healthy heart structure and function. Participants with low vitamin D and K levels experienced cardiac structural changes and other adverse risks. Participants who had normal vitamin D levels, but low vitamin K levels also had changes in cardiac function. Studies show vitamin D levels of 40-60 ng/mL are associated with optimal heart and overall health benefits.

Bones

Vitamins D and K work together to support continuous bone building and remodeling. Research shows that their combined use enhances calcium absorption into bones, stimulates bone growth, and activates key transcription factors that promote bone formation and density. This synergy helps strengthen bones, supports mineralization, reduces bone breakdown, and upregulates gene expression of markers linked to bone health.

Health Span and Longevity

Vitamin D and K sufficiency has also been shown to affect your health span and longevity. Lower tissue levels increase health risks and overall decline as demonstrated in the PREVEND study.

Other research shows that vitamin K2 intake reduces certain health risks and supports longevity. Vitamin D also plays an important role in reducing several health risks and overall cause of mortality.

Sufficient Vitamin D and vitamin K levels are associated with longer telomere length which is associated with brain health, overall vitality and longevity.

Breast Health

Promising new research evaluated the impact of vitamin D3 and K2 on cellular health in breast tissues. Support by either nutrient was helpful, however, when combined, results showed a synergistic effect on cell cycle arrest and apoptosis, supporting breast health.

Brain and Cognitive Function

Brain health and cognitive function deeply depend on the fat-soluble vitamins D and K. For example, vitamin K2 is vital for sphingolipid synthesis, which are types of lipids needed in high amounts in nerve and glial cell membranes for cell signaling function and structural effects in the brain and peripheral nervous system.

The drug Warfarin (Coumadin) interferes with vitamin K function in the brain causing adverse changes with sphingolipids production. A recent autopsy study on adults who used Warfarin showed lower brain concentrations of vitamin K2.

Vitamin D plays several major roles in brain health. In its active state, vitamin D is a neurosteroid that orchestrates neurotransmitter turnover, neurogenesis and neuroplasticity. It provides invaluable stability to nerves, balancing excitatory and inhibitory reactions in the brain. Insufficient vitamin D provokes an increase in excitatory glutamate levels and other stress reactions in the brain, whereas optimal vitamin D is neuroprotective.

Are You Getting Enough Vitamin D and K?

A recent study in Austria demonstrated the need for vitamin support in healthy adults 70-90 years of age. Of the 102 participants, 49% supplemented regularly while the others did not. Blood tests showed that regardless of supplementation, 88% of participants were deficient in vitamin D and 42% had inadequate vitamin K levels. Participants were also deficient in or more likely to need more B vitamins.

Seniors need more nutritional support than others as they are likely to suffer from malnutrition and poor digestion due to age related decline. Skipping meals, isolation and loneliness, lack of appetite, limited cooking abilities, financial constraints, etc. also contribute to lower nutrient intake.

Furthermore, dental concerns, medications that interfere with digestion or block absorption of nutrients, and other factors cause nutritional deficiencies that lead to a higher demand for nutritional support.

For all ages, the need for vitamin D and K increases with compromised digestive health whether it’s from diminished production of pancreatic enzymes, bowel motility concerns, protection for gallbladder health or gallbladder removal.

Sunscreen Use

Another example of increased need for vitamin D and K supplementation pertains to sunscreen use. Sweltering summer heat or concerns for skin protection cause many individuals to use sunscreen, but that blocks vitamin D. Individuals may recognize this need and take a vitamin D supplement but fail to recognize that vitamin K2 is required for vitamin D metabolism.

A recent survey study of 50 adults using sunscreen revealed this concern. Only 4 out of the 50 adults understood the requirement to supplement vitamin D3 and K2 together and only 1 out of 50 supplemented with vitamin K2. 

Medications

People of all ages use medications that interfere with vitamin D and K absorption or metabolism. One widely known drug is Warfarin or Coumadin. It inhibits vitamin K dependent activities in bones, heart, brain, mitochondria, and elsewhere in the body. It is damaging to your health to avoid vitamin K when taking Warfarin.

Research shows that those who are on Warfarin require vitamin K supplementation with proper lab monitoring to maintain healthy physiological functions. Please work with your prescribing medical doctor for specific advice on this issue.

More information about medications affecting vitamin D and K may be found in the Additional Resources section below.

Vitamin D and K Supplements

At the time of this writing, there were over 110,000 studies on vitamin D and over 33,000 on vitamin K. Moreover, understanding how these two fat-soluble vitamins work together is still unfolding, but it is certain to say the effects are synergistic and require each other for full functionality. Optimizing your health with vitamin D and K is as essential as a daily multiple vitamin, omega-3 fish oils, magnesium and dietary fiber. Your body can’t live without them!

Many Quality Supplement Options

Wellness Resources offers several options with vitamin D3 and K1, K2. These include:

• Vitamin D3+K2 – new! – 5,000 IU vitamin D3 and 100 mcg Vitamin K2

• Vitamin D3 1000 IU and 2500 IU per capsule

• Vitamin K Complex with vitamin K1, K2 (MK4 and MK7)

• Daily Bone Xcel with smaller amounts of vitamin D and K combined with high amounts of calcium along with magnesium, and trace minerals for bone health.

• Daily Builder with small amounts of vitamin D and K combined in a 2:1 ratio of calcium: magnesium with glucosamine, niacinamide, lysine, and trace minerals for bone and joint health.

• Bone & Joint Helper – Vitamin K2 and D3 with patented herbs for bone mass, joint comfort and mobility.

Additional valuable information may be found in the articles:

The Hidden Impact: Meds that Deplete Vitamin D and How It Affects Your Health

New Discoveries Highlight the Importance of Vitamin D

Vitamin D and Your Immune System – Are You Getting Enough?

Vitamin K: It Helps More Than Just Bones

Vitamin K Critical for Bones and Arterial Health

Sunscreen Dangers Continue to be Exposed