Table 2.

Subgroup analysis of the effect of vitamin D on all cause mortality

Subgroup title	No of trials	No of participants	I2 (%)	Risk ratio (95% CI)	P for interaction
Overall	50	74 655	0	0.98 (0.95 to 1.02)	—
No of participants:
≥2000	11	63 793	24	0.99 (0.95 to 1.03)	0.65
<2000	39	10 862	0	0.95 (0.81 to 1.11)
No of events:
≥200	8	54 168	0	0.99 (0.95 to 1.03)	0.85
<200	42	20 487	0	0.97 (0.85 to 1.11)
Age (years):
≥70	22	39 390	0	1.00 (0.90 to 1.11)	0.78
<70	28	35 265	17	0.98 (0.94 to 1.02)
Sex:
Female	14	17 671	20	0.95 (0.86 to 1.05)	0.47
Male and female	36	56 984	0	0.99 (0.95 to 1.03)
Baseline mean 25 hydroxyvitamin D (nmol/L):
≥50	18	50 466	0	1.04 (0.97 to 1.12)	0.07
<50	26	16 080	19	0.95 (0.90 to 1.01)
Year of publication:
Before 2014	33	37 088	5	0.98 (0.94 to 1.02)	0.77
In or after 2014	17	37 567	0	1.00 (0.90 to 1.11)
Type of vitamin D:
Vitamin D3	40	57 111	0	0.95 (0.91 to 1.00)	0.04*
Vitamin D2	10	17 544	12	1.03 (0.98 to 1.09)
Daily dose equivalent (IU):
<2000	30	39 785	0	0.98 (0.94 to 1.02)	0.56
≥2000	16	34 116	0	1.01 (0.91 to 1.13)
Timing:
Daily	31	47 931	0	0.99 (0.94 to 1.04)	0.79
Intermittently	15	25 815	0	0.98 (0.93 to 1.03)
Bolus or not:
Bolus	10	24 612	0	0.98 (0.93 to 1.04)	1.00
Non-bolus	36	49 134	0	0.98 (0.93 to 1.04)
Residential status:
Community	41	62 362	0	0.97 (0.92 to 1.02)	0.31
Institution	9	12 293	0	1.01 (0.96 to 1.06)
Follow-up:
At least three years	12	57 818	0	0.97 (0.93 to 1.01)	0.26
Less than three years	38	16 837	6	1.02 (0.95 to 1.11)
Intervention:
Vitamin D	34	62 767	0	1.00 (0.96 to 1.05)	0.08
Vitamin D plus calcium	16	11 888	0	0.93 (0.87 to 1.00)
Latitude:
≥40°	36	41 002	5	0.99 (0.95 to 1.03)	0.71
<40°	13	33 135	0	0.97 (0.87 to 1.08)

^*Statistically significant.