Role of Vitamin D in Osteoarthritis: Molecular, Cellular, and Clinical Perspectives

Table 4

Summaries of randomised clinical trials to assess the efficacy of vitamin D supplementation for the treatment of knee osteoarthritis.

Reference	Country	Supplement	Dose	Condition of samples	Vitamin D status of participants	Samples/placebo	Vitamin D assay	Follow-up	Results
Sanghi et al. [28] 2013	India	Cholecalciferol granules or placebo	60,000 IU per day for 10days followed by 60,000 IU once a month for 12 months	>40 yrs old; ACR Criteria; WOMAC pain >4 for at least 6 months; 6 months of conventional treatment; BMI <30; No previous fracture or surgery to knee	Vitamin D insufficiency (25(OH)D ≤ 50 nmol/L)	52/51	EIA	Multiple over a 12-month period	Vit D = ↓ VAS and WOMAC pain scores versus placebo; Vit D = ↓ WOMAC physical + total versus placebo; Vit D = ↑ serum calcium, 25(OH)D, and alkaline phosphatase versus placebo; No difference in WOMAC stiffness
McAlindon et al. [29] 2013	USA	Cholecalciferol or placebo	2,000 IU daily with subsequent adjustment in 2000 IU increments at 4, 8, and 12 months for a target 25OHD level between 36 and 100 ng/mL	Age > 45; Symptomatic knee OA; KL ≥ 2 (ACR Criteria) WOMAC = mild pain	Not selected for	73/73	LC/MS/MS	Multiple over a 24-month period	Vit D levels ↑ over the 2 years; No significant difference in knee pain between groups; No significant differences between cartilage loss, JSW, and BML size; No significant difference in WOMAC pain or function scores

Vit D: vitamin D; BMI: body mass index; ↑: higher/increased; =: association; ACR: American College of Rheumatology; WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index; KL: Kellgren-Lawrence grading; VAS: visual analogue score; JSW: joint space width; BML: bone marrow lesion; EIA: enzyme immunoassay; LC/MS/MS: liquid chromatography-tandem mass spectrometry.