Table II.

Subgroup analysis of the effects of vitamin K supplementation on femoral neck, lumbar spine, and total hip bone mineral density.

Subgroup	Femoral neck BMD (g/cm2)				Lumbar spine BMD (g/cm2)				Total hip BMD (g/cm2)
	N	WMD (95% CI)	Heterogeneity		N	WMD (95% CI)	Heterogeneity		N	WMD (95% CI)	Heterogeneity
			I 2	p-value			I 2	p-value			I 2	p-value
Intervention
Vitamin K1	4	-0.00 (-0.01 to 0.01)	0.0%	0.657	3	-0.00 (-0.01 to 0.0)	0.0%	0.398	1	0.00 (-0.05 to 0.06)	N/A†	0.954
Vitamin K2	6	0.02 (-0.00 to 0.04)	88.2%	0.100	9	0.02 (0.00 to 0.03)	93.1%	0.028	5	0.01 (-0.01 to 0.03)	81.2%	0.173
Dose, mg/day
≤ 1	6	-0.00 (-0.01 to 0.00)	0.0%	0.671	5	-0.00 (-0.01 to 0.00)	0.0%	0.132	3	0.01 (-0.00 to 0.01)	0.0%	0.113
> 1	4	0.03 (-0.01 to 0.06)	92.7%	0.175	7	0.02 (0.01 to 0.04)	94.4%	0.008	3	0.03 (-0.03 to 0.10)	90.2%	0.348
Duration, yrs
≤ 1	4	0.03 (-0.02 to 0.08)	90.9%	0.2290	7	0.02 (0.00 to 0.04)	94.9%	0.020	3	0.03 (-0.03 to 0.10)	84.9%	0.275
> 1	6	-0.00 (-0.01 to 0.00)	0.0%	0.600	5	-0.00 (-0.01 to 0.01)	0.0%	0.859	3	0.00 (-0.01 to 0.01)	26.7%	0.664
Country
Asia	4	0.03 (-0.02 to 0.08)	90.9%	0.229	6	0.03 (-0.01 to 0.07)	93.1%	0.103	3	0.03 (-0.03 to 0.10)	84.9%	0.275
Other continents	6	-0.00 (-0.01 to 0.00)	0.0%	0.660	6	-0.00 (-0.01 to 0.0)	0.0%	0.148	3	0.00 (-0.01 to 0.01)	26.7%	0.664
Sex
Female	7	0.01 (-0.0 to 0.02)	86.0%	0.188	9	0.01 (0.00 to 0.03)	93.7%	0.028	4	0.02 (-0.01 to 0.04)	85.9%	0.150
Female and male	3	0.00 (-0.01 to 0.02)	0.0%	0.630	3	0.00 (-0.03 to 0.03)	0.0%	0.942	2	0.00 (-0.03 to 0.03)	0.0%	0.866
Position
L1-L4					4	-0.00 (-0.01 to 0.00)	0.0%	0.062
L2-L4					8	0.02 (0.00 to 0.05)	91.6%	0.019
Health status
Healthy									3	-0.00 (-0.01 to 0.01)	0.0%	0.460
Unhealthy*									3	0.03 (-0.02 to 0.09)	88.2%	0.251

^*Participants with osteoporosis or osteopenia.

^†Only one document included, not shown.

BMD, bone mineral density; N/A, not applicable; WMD, weighted mean difference.