vitamin

Vitamin D3 + K2

Also known as: D3/K2, D3 with K2, Cholecalciferol + Menaquinone

Evidence: High · 100%
Chemical structure of Vitamin D3 + K2 (PubChem CID 5280795)
Structure via PubChem
Half-life
Typical timing
morning
Food rule
with food
Default unit

Studied for

Deficiency-driven — not a performance booster

Vitamins primarily help when you're actually low. Extra doses on top of normal levels rarely add strength, endurance, or fat loss, and some fat-soluble vitamins (A, D, E, K) can build up to harmful levels.

  • Confirm a deficiency with bloodwork before supplementing long-term (e.g. 25(OH)D for vitamin D, B12/folate, ferritin, magnesium RBC).
  • Talk to your doctor or a registered dietitian about the right dose for your labs, medications, and conditions — especially in pregnancy, kidney/liver disease, or while on blood thinners.
  • Re-test every 3–6 months and stop or lower the dose once levels are in range.

Educational information only — not medical advice. See our AI & medical policy.

Overview

Vitamin D3 (cholecalciferol) and Vitamin K2 (menaquinone) are fat-soluble vitamins that play distinct yet synergistic roles in human health. Vitamin D3 is primarily known for its essential function in calcium absorption and bone mineralization. It is synthesized in the skin upon exposure to ultraviolet B (UVB) radiation and can also be obtained from certain foods or supplements. Vitamin K2 is a less well-known but crucial nutrient, primarily involved in regulating calcium metabolism and ensuring its proper distribution in the body. It activates specific proteins that either integrate calcium into bone or prevent its deposition in soft tissues like arteries and kidneys. While many foods contain Vitamin K1 (phylloquinone), K2 is found in fermented foods, certain animal products, and can also be produced by gut bacteria. The combination of D3 and K2 is often studied due to their complementary actions, particularly concerning bone density and cardiovascular health. Individual nutritional needs for these vitamins can vary significantly based on diet, sun exposure, age, and health status. Consultation with a licensed clinician is recommended to determine appropriate intake. Why vitamins for muscle and weight-loss: The D3 in this stack supports strength, recovery, and metabolic health when levels are low; K2 helps direct calcium to bone rather than soft tissue. Neither is ergogenic — the benefit is deficiency correction. Test 25-OH vitamin D first and re-test after 8-12 weeks. References: Owens DJ et al. Vitamin D and the athlete. Nutrients. 2018;10(2):220; Maresz K. Proper calcium use: vitamin K2 as a promoter of bone and cardiovascular health. Integr Med (Encinitas). 2015;14(1):34-9.

Deep dive

Tap a section to expand.

Known interactions

  • Category rule: vitamin × medication
    Note

    Certain vitamins interact with specific medications (e.g., vitamin K with blood thinners).

    Specific pairs are checked against a licensed source; confirm with your provider.

Frequently asked

Sources referenced

- National Institutes of Health (NIH) Office of Dietary Supplements (ODS) - MedlinePlus (National Library of Medicine) - Examine.com - DrugBank - Mayo Clinic - Cochrane Library - European Medicines Agency (EMA) Summary of Product Characteristics (SmPC) for relevant compounds

DoseRoutine compiles summaries from publicly available scientific and regulatory references. Always verify important decisions with a licensed clinician.

Cite this page

Using this in an article, AI answer, or research note? Please attribute:

DoseRoutine. (2026). Vitamin D3 + K2 — Overview, Benefits & Side Effects. Retrieved from https://doseroutine.com/library/vitamin-d3-k2
Canonical URL

Related compounds

Others in the vitamin category or studied for the same goals.

Related benefits

Other compounds studied for the same benefits as Vitamin D3 + K2.

Continue exploring

See every compound DoseRoutine catalogues for these goals.

Track Vitamin D3 + K2 in DoseRoutine

Add it to your stack. We'll schedule doses, check interactions against everything else you take, and remind you at the right time.

Sign up free →