Table 2.

Observational studies for the effect of vitamin K in bone mineral density and fractures since 2015

Study, year [ref]	Population	N	ucOCN	Serum VK	VK measure method	BMD	BTM	Fracture risk	Other
Kim et al., 2015 [102]	Korean adults	7092	–	–	–	Decrease in women with low VK intake	–	–	–
Popko et al., 2018 [103]	Caucasian children with low energy fractures	39	yes	–	–	–	No differences (NTx, BALP, Calcium, vitD)	Decreased with better VK status	–
Evenepoel et al., 2019 [104]	Adult patients (mostly Caucasian) with CKD	468	–	–	–	Decrease when high ucMGP	No change	Increased when low ucMGP	–
Nalevaiko et al., 2021 [105]	Men and women on anticoagulants (DOACs or warfarin) for at least 1 year	150	–	–	–	Decrease (more with warfarin)	–	–	Decreased TBS (more with warfarin)
Finnes et al., 2016 [76]	Caucasian men and women 65–79 years old	2331	–	Yes	HPLC	–	–	Decreased hip fx in high VK1 and vit D	–
Tejero et al., 2016 [75]	Adolescents and adults with cystic fibrosis	50	–	Yes	HPLC	No difference	No difference	–	–
Jaghsi et al., 2018 [106]	Syrian postmenopausal OP women and postmenopausal healthy control women	23	–	Yes	ELISA	Increased with high VK1	–	–	–
Moore et al., 2020 [74]	Postmenopausal women with OP	374	–	Yes	LCMSMS	No difference	–	Increased in low levels of VK1	Increased cross–sectional area, cross sectional moment of inertia and section modulus at the narrow neck of femur; decreased ucMGP in high VK1 levels

ucOCN undercarboxylated OCN, fx fracture, TBS trabecular bone score, CKD chronic kidney disease, LCMSMS liquid chromatography tandem mass spectrometry