Table 1. Characteristics of the included studies.

First Author	Publishing Year	Country	Intervention Method	Concomitant Disease	Number of Patients in BPs/Vitamin D/Combination Groups	Mean Age in BPs/Vitamin D/Combination Groups	Number of Males/Females in BPs, Vitamin D, Combination Groups
Shigeki Yamada [12]	2007	Japan	Risedronate (2.5 mg) or Alfacalcidol (0.5 μg) daily for 48 weeks, with 800 mg/d calcium supplement	rheumatoid arthritis	6/6/-	69.2/72/-	0/6,0/6,-
Naohiko Fujii [13]	2007	Japan	Risedronate 2.5 mg/d or Vitamin D (dose unreported) or the combination for 1 year	chronic kidney disease	23/37/40	41.1/42.2/40	12/11,16/21,15/25
Yuichi Kikuchi [14]	2007	Japan	Risedronate 2.5 mg/d or Alfacalcidol 0.5 mg/d or the combination for 1 year	glomerular disease	12/15/11	39.9/41.5/43.7	6/6,8/7,5/6
Yosuke Okada [15]	2008	Japan	Alfacalcidol 1 μg/d alone or Alfacalcidol 1 μg/d with Alendronate 5 mg/d for 18 months	autoimmune disease	-/22/25	-/31.4/32.5	-,0/22,0/25
Seiji Takeda [16]	2008	Japan	Risedronate (5 mg) or Alfacalcidol(1 μg) daily for 24 months, with 800 mg/d calcium supplement	systemic autoimmune diseases	17/16/-	49.2/45/-	0/17,0/16,-
S. Kitazaki [11]	2009	Japan	Alendronate (5 mg⁄ day) or Alfacalcidol (1 mg⁄ day) daily for 12 months	ulcerative colitis	14/18/-	41.2/38.1/-	10⁄6,12/8,-
Edmund K Li [17]	2010	China	Ibandronate (150 mg) or Alfacalcidol (1 μg) daily for 12 months with 500 mg/d calcium supplement	systemic lupus erythematosus	20/20/-	47/45.5/-	0/20,0/20,-
Yoshiya Tanaka [18]	2015	Japan	Alendronate 35 mg/week or Alfacalcidol 1 μg/day or combination for 12 months	systemic rheumatic diseases	33/28/33	47.3/48.7/45.3	0/33,0/28,0/33
Kichul Shin [19]	2017	Korea	Ibandronate 150 mg every 4 weeks or 400IU cholecalciferol daily for 48 weeks with 600 mg calcium supplement	rheumatoid arthritis and osteopenia	76/73/-	54.5/55.1/-	0/76,0/73,-