Vitamin K

Should vitamin K be taken with vitamin D?

Updated 3 Nov 2026

Short answer

Some supplements combine them, and a 2020 meta-analysis found a small gain in bone density from the pair.[1][2] It pooled 8 trials with 971 people. Vitamin K with vitamin D raised total bone density a little.[2] When only the vitamin K group also gets vitamin D or calcium, part of the effect may come from them.[1]

In bone trials that gave calcium and vitamin D to everyone, vitamin K added no bone density.[3][4] A 2-year trial included 365 men with calcium in the aortic valve. In it, 720 µg of MK-7 with 25 µg of vitamin D a day did not slow calcium build-up in the valve.[5]

Sources (5)

  1. Vitamin K: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov
  2. The combination effect of vitamin K and vitamin D on human bone quality: a meta-analysis of randomized controlled trials. Kuang X, Liu C, Guo X, Li K, Deng Q, Li D Food Funct, 2020. PMID 32219282
  3. Vitamin K treatment reduces undercarboxylated osteocalcin but does not alter bone turnover, density, or geometry in healthy postmenopausal North American women. Binkley N, Harke J, Krueger D, Engelke J, Vallarta-Ast N, Gemar D, et al. J Bone Miner Res, 2009. PMID 19113922
  4. Effect of vitamin K supplementation on bone loss in elderly men and women. Booth SL, Dallal G, Shea MK, Gundberg C, Peterson JW, Dawson-Hughes B J Clin Endocrinol Metab, 2008. PMID 18252784
  5. Vitamin K2 and D in Patients With Aortic Valve Calcification: A Randomized Double-Blinded Clinical Trial. Diederichsen ACP, Lindholt JS, Möller S, Øvrehus KA, Auscher S, Lambrechtsen J, et al. Circulation, 2022. PMID 35465686

More about vitamin k

What is vitamin K?Which foods contain vitamin K?What is vitamin K used for?Who is at risk of vitamin K deficiency?Is vitamin K safe?Why do newborn babies get vitamin K?

For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.