Eligibility Criteria:
Inclusion Criteria:
* Informed Consent as documented by signature
* 18 years or older at the time of informed consent signature
* Complication-free rotator cuff\* or shoulder arthroscopy\*\* with or without resection of the acromioclavicular joint at the orthopedics Sonnenhof. The rotator cuff operations are basically open or in mini-open technique, usually with additional tenotomy / tenodesis of the long biceps tendon.
\* rotator cuff surgery can include tenotomy/tenodesis of long biceps tendon, intra-articular debridement with or without resection of the coracoacromial ligament and/or acromioplasty, biopsies, diagnostic arthroscopy
\*\* Arthroscopic procedures include subacromial debridement (including partial resection of the coracoacromial ligament \& acromioplasty), diagnostic arthroscopy, tenotomy of the long biceps tendon, intra-articular debridement, resection of calcium depots for treatment of tendinitis calcarea, biopsies, stabilizations (only without postoperative immobilization)
* Sufficient knowledge of German to understand the patient information and informed consent, follow instructions by study personnel, and complete patient questionnaires \& diary
Exclusion Criteria:
* Contraindications to ascorbic acid or one of the excipients, e.g. known hypersensitivity or allergy to the investigational product
* Planned single or multiple intake of vitamin supplements during the study period, which results in an additional daily intake of \> 50 mg ascorbic acid
* Known pregnancy or breast feeding
* Known or suspected non-compliance, for example drug or alcohol abuse
* Inability to follow the procedures of the study, e.g. due to psychological disorders, dementia, etc.
* Participation in another interventional study within the 30 days preceding and during the present study
* Previous enrollment into the current study
* Enrollment of the investigator, his / her family members, employees and other dependent persons
* Current or previous frozen shoulder (no matter on which side)
* Pre-surgery on the affected shoulder joint (preoperative procedures include all procedures examined in this study, including all other procedures involving the glenohumeral joint and / or acromioclavicular joint. In addition, all interventions, which as a result, negatively influence the mobility of the shoulder with great likelihood up to the current time)
* Known current unstable medical problem on the not-affected shoulder joint according to the judgment of the investigator
* Taking a cortisone preparation or an immunomodulatory drug (for example methotrexate or similar)
* Alcoholism (defined as intake of more than 12g (women) or 24g (men) alcohol per day)
* Regular hemodialysis
* Known diabetes mellitus
* Known Addison's disease
* Known not correctly adjusted thyroid metabolism
* Known Parkinson's disease and similar CNS disorders (Diffuse Lewy Body Disease, Corticobasal Degeneration, Multisystem Atrophy, Progressive Supranuclear Paralysis, Essential Tumor, Huntington's Disease, Multiple Sclerosis)
* Known diseases / injuries of the peripheral nerves (Isaac's Syndrome, Stiff-Person Syndrome, Guillain-Barré Syndrome, Chronic Inflammatory Demyelinating Polyneuropathy, Hereditary Neuropathies, Amyotrophic Lateral Sclerosis, Hereditary Motor Neuropathies Prone to Pressure Paralysis, Motor Neurone Diseases, Myasthenia Gravis, Spinal Muscular Atrophies, Thoracic Outlet Syndromes)
* Known infection in the shoulder joint to be operated
* Known Hyperlipidemia
* Known Uremia
* Known Thalassemia
* Known iron storage diseases
* Known Glucose-6-phosphate dehydrogenase (G6PD) deficiency
* Planned further operation of any kind within the next 50 days after shoulder surgery