Table 2.

Summary of randomized controlled trials examining the effect of calcium and vitamin D supplementation on fracture risk

Study	n	Dose	Adherence	Fracture (95% CI)
Vitamin D3 alone
Meyer et al. [24]	1144	400 IU	33%	Hip RR = 1.09 (0.73−1.63); nonvertebral RR = 0.92 (0.66−1.27)
Lips et al. [23]	2578	400 IU (cod liver oil)	63%	Hip HR = 1.18 (0.81−1.71); nonvertebral HR = 1.03 (0.75−1.4)
Trivedi et al. [13]	2686	100,000 IU every 4 months	80%	All RR = 0.78 (0.61−0.99); nonvertebral RR = 0.67 (0.46−0.99)
Vitamin D3 < 800 IU plus calcium ≤ 1000 mg
Dawson-Hughes et al. [14]	389	700 IU, 500 mg	93%	All fractures RR = 0.4 (0.2−0.8); nonvertebral RR = 0.4 (0.2−1)
Larsen et al. [15]	9605	400 IU, 1000 mg	Not reported	Hospitalized osteoporotic RR = 0.78 (0.63−0.96)
Jackson et al. [20]	36,282	400 IU, 1000 mg	59%	Hip HR = 0.88 (0.72−1.08)
Vitamin D3 800 IU plus calcium ≥ 1000 mg
Chapuy et al. [11]	3270	800 IU, 1200 mg	83%	Hip OR = 0.57 (0.37−0.9); nonvertebral OR = 0.75 (0.61−0.91)
Chapuy et al. [12]	583	800 IU, 1200 mg	95%	Hip OR = 0.59 (0.33−1.04); nonvertebral not significant
Grant et al. [22]	5292	800 IU, 1000 mg	47%	All fractures HR = 1.01 (0.88−1.17)
Porthouse et al. [21]	3314	800 IU, 1000 mg	59%	Hip OR = 0.75 (0.31−1.43); nonvertebral OR = 0.89 (0.56−1.44)