Answer
Injection or infusion is used when deficiency is acute or oral or dietary replacement is unsuitable or difficult.
Sources for this answer
- Ascorbic Acid Injection 500mg/5ml — Current selected SmPCemc · Summary of Product Characteristics
- Ascorbic Acid Pascoe 150 mg/ml Concentrate for solution for injection / infusion — Current selected SmPCemc · Summary of Product Characteristics
General medicine information. Follow the instructions for your own medicine and speak to a pharmacist or clinician about your individual circumstances.