Can I Take Vitamin D3 and K2 Together? Safe Dosage & Timing Guide

Vitamin D3 and Vitamin K2 work synergistically for bone and cardiovascular health. Learn the safe dosage, optimal ratio, and best time to take them together based on 5 regional safety standards.

Quick Answer

Vitamin D3 increases calcium absorption; Vitamin K helps direct calcium to bones.

Recommendation: Consider taking both together for bone health.

vitamin d3 + vitamin k

Low Riskratio imbalance

Vitamin D3 increases calcium absorption; Vitamin K helps direct calcium to bones.

Tip: Consider taking both together for bone health.

Safe Dosage Comparison (5 Regional Standards)

Standardvitamin d3vitamin k
US (FDA)600 / 4000 IU
(RDA/UL)
120 / 1000 mcg
(RDA/UL)
EU (EFSA)600 / 4000 IU
(RDA/UL)
120 / 1000 mcg
(RDA/UL)
AU (TGA)600 / 4000 IU
(RDA/UL)
120 / 1000 mcg
(RDA/UL)
CN (CNS)600 / 4000 IU
(RDA/UL)
120 / 1000 mcg
(RDA/UL)
JP (MHLW)600 / 4000 IU
(RDA/UL)
120 / 1000 mcg
(RDA/UL)

Values shown as RDA (Recommended Dietary Allowance) / UL (Tolerable Upper Intake Level). Sources: NIH, FDA, EFSA, FSANZ, CNS, MHLW.

Frequently Asked Questions

Can I take vitamin D3 and K2 at the same time?

Yes. Vitamin D3 and K2 are commonly taken together and work synergistically. Vitamin D3 enhances calcium absorption, while vitamin K2 directs calcium to bones and teeth rather than arteries. According to NIH, this combination supports both bone density and cardiovascular health.

What is the best ratio of vitamin D3 to K2?

A common recommendation is 100-200 mcg of K2 (as MK-7) per 1000 IU of vitamin D3. However, there is no officially established optimal ratio. The key is ensuring adequate K2 intake when supplementing with D3, as D3 increases calcium absorption which K2 helps direct properly.

Taking More Supplements?

This page only checks one pair. Use NutriAudit to check your full supplement stack for interactions, duplicates, and safe dosages.

Not medical advice. Always consult a qualified healthcare professional for personal medical decisions.