Effect of adjunctive vitamin C supplementation in patients with grade II osteoarthritis

Comparison of the effectiveness of adjunctive supplementation with vitamin C (500 or 1,000 mg) to standard care on pain severity, sleep quality, knee function, and general health status in patients with grade II osteoarthritis

Status

Active, not recruiting

Phases

Phase 3

Study type

Interventional

Source

IRCT

Registry ID

IRCT20250527065925N2

Enrollment

126

Registered

2026-05-01

Start date

2025-09-23

Completion date

Unknown

Last updated

2026-06-01

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Osteoarthritis of knee. Osteoarthritis of knee

Interventions

Intervention 1: Intervention group 1: Vitamin C 500 mg (once daily) + Omega-3 capsule (once daily) + Nofenac capsule (every 8 hours) + Osteoquinon capsule (once daily). Intervention 2: Intervention gr

Eligibility

Sex/Gender

All

Age

18 Years to 65 Years

Inclusion criteria

Inclusion criteria: Grade II knee osteoarthritis according to the Kellgren–Lawrence classification age > 18 years and < 65 years

Exclusion criteria

Exclusion criteria: use of analgesic (pain-reducing) medications use of addictive substances presence of autoimmune diseases BMI > 30 kg/m² use of specific dietary supplements such as multivitamins and/or supplements containing vitamin C

Design outcomes

Primary

Measure	Time frame
Pain intensity. Timepoint: immediately Post-intervention: 1 Month , 2 Month and 3 Month after intervention. Method of measurement: visual analog scale.	—

Secondary

Measure	Time frame
Knee function. Timepoint: immediately Post-intervention: 1 Month , 2 Month and 3 Month after intervention. Method of measurement: Knee injury and Osteoarthritis Outcome Score.;General health. Timepoint: immediately Post-intervention: 1 Month , 2 Month and 3 Month after intervention. Method of measurement: General Health Questionnaire.;Sleep quality. Timepoint: immediately Post-intervention: 1 Month , 2 Month and 3 Month after intervention. Method of measurement: Pittsburgh Sleep Quality Index.	—

Measure

Time frame

Knee function. Timepoint: immediately Post-intervention: 1 Month , 2 Month and 3 Month after intervention. Method of measurement: Knee injury and Osteoarthritis Outcome Score.;General health. Timepoint: immediately Post-intervention: 1 Month , 2 Month and 3 Month after intervention. Method of measurement: General Health Questionnaire.;Sleep quality. Timepoint: immediately Post-intervention: 1 Month , 2 Month and 3 Month after intervention. Method of measurement: Pittsburgh Sleep Quality Index.

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Countries

Iran (Islamic Republic of)

Contacts

Public ContactDanial Hosseinzadeh

Babol University of Medical Sciences

d.hosseinzadeh@mubabol.ac.ir+98 11 3235 0451

Outcome results

None listed

Source: IRCT (via WHO ICTRP) · Data processed: Jun 11, 2026