Table 2.

Randomized clinical trials of vitamin D supplementation on the progression of knee osteoarthritis (OA) and related symptoms ¹.

				Serum 25(OH)D (nmol/L)			Vitamin D Intervention	Results
			Duration (years)	Baseline	Post-Intervention
		n			Control	Treatment
Joint pain and function
Sanghi et al. [61]	India	103	1	37	39	83	60,000 IU/d for 10 d followed by 60,000 IU/mo	Vitamin D reduces pain (but unlikely to be clinically relevant)
Arden et al. [55]	UK	468	3	63	61 2	84 2	800 IU/d	No effect of vitamin D
Chelbowski et al. [56]	USA	1911	2	Not reported	Not reported	Not reported	400 IU/d (+1000 mg Ca)	No effect of vitamin D (joint not specified)
McAlindon et al. [57]	USA	146	2	56	62	96	2000 IU/d plus dose escalation to reach over 90 nmol/L	No effect of vitamin D
Jin et al. [58]	Australia	413	2	44	51	84	50,000 IU/mo	No effect of vitamin D
Wang et al. [60]	Australia	340	2	44	51	84	50,000 IU/mo	Vitamin D retards effusion synovitis
Radiologic OA
Arden et al. [55]	UK	427–441 3	3	63	61 2	84 2	800 IU/d	No effect of vitamin D
McAlindon et al. [57]	USA	146	2	56	62	96	2000 IU/d plus dose escalation to reach over 90 nmol/L	No effect of vitamin D
Cartilage volume loss
McAlindon et al. [57]	USA	146	2	56	62	96	2000 IU/d plus dose escalation to reach over 90 nmol/L	No effect of vitamin D
Jin et al. [58]	Australia	413	2	44	51	84	50,000 IU/mo	No effect of vitamin D

¹ 25(OH)D: 25-hydroxyvitamin D. ² Serum 25(OH)D measures at year 1 of intervention. Mean serum vitamin D status at the end of the intervention (year 3) was not reported. ³ Depending on site.