Table 3.
The effect of vitamin C on cancer-related pain
| Study type | Intervention | Findings |
|---|---|---|
| Uncontrolled prospective | ||
| Advanced cancer [90] | 0.8–3 g IV vitamin C/kg body weight (N = 17) 4 days/week for 4 weeks | Before: 36% pain (N = 17) Week 1: 35% pain (N = 16) Week 2: 35% pain (N = 12) Week 3: 29% pain (N = 7) Week 4: 0% pain (N = 2) (EORTC QLQ) |
| Advanced cancer [89] | 25–100 g IV vitamin C (N = 60) twice weekly for 4 weeks | Before: 18% pain Week 2: 14% pain Week 4: 10% pain (EORTC QLQ) |
| Terminal cancer [88] | 10 g IV vitamin C (N = 39) twice over 1 week 4 g/day oral vitamin C for 1 week | Before: 30% pain Week 1: 21% pain (EORTC QLQ) |
| Controlled retrospective | ||
| Bone metastases [84] | i. Control (N = 9) | i. ↑ pain (VAS) |
| ii. Chemotherapy (N = 15) | ii. 0–80% ↓ pain | |
| iii. 2.5 g IV vitamin C (N = 15) during pain | iii. 0–100% ↓ pain, mean 50% ↓ pain | |
| Breast cancer [87] | i. Control (N = 72) | i. 15% pain |
| ii. 7.5 g IV vitamin C (N = 53) once weekly for ≥ 4 weeks | ii. 10% pain* (intensity of complaints during adjuvant therapy) | |
| Uncontrolled retrospective | ||
| Bone metastases [83] | 2.5 g IV vitamin C (N = 11) once weekly for 3–10 weeks | 0–100% ↓ pain (VAS), mean 49% ↓ pain |
| Case report | ||
| Breast cancer [133] | 50 g IV vitamin C twice weekly for 4 weeks | Before: 17% pain After: 8% pain (EORTC QLQ) |
| Terminal cancer [95] | 30 g/day IV vitamin C for 1 week | Before: 17% pain After: 0% pain (EORTC QLQ) |
| Metastatic breast cancer [81] | 10 g/day oral vitamin C for 550 days | Pain relief for >1 year |
| Breast cancer with skeletal metastases—severe pain [81] | 5 g/day IV vitamin C for 7 days 8 g/day oral vitamin C for 70 days |
Complete ↓ bone pain from day 4 |
| Bladder cancer with skeletal metastases—intense pain [81] | 10 g/day IV vitamin C for 10 days 10 g/day oral vitamin C for 24 days |
Dramatic ↓ bone pain |
| Breast cancer with osteolytic metastases—severe bone pain [81] | 10 g/day IV vitamin C for 7 days 10 g/day oral vitamin C for 27 days |
Complete ↓ bone pain |
EORTC QLQ European Organisation for the Research and Treatment of Cancer Quality of Life Questionnaire, IV intravenous, VAS visual analogue scale
* P < 0.05