What is the recommended dose of subcutaneous Vitamin C (Ascorbic Acid)?

From the Guidelines

The recommended dose of subcutaneous vitamin C should not exceed 500 mg daily, and it is prudent to avoid supplemental vitamin C, especially in patients with iron overload and during the induction phase. When administering subcutaneous vitamin C, it is essential to consider the potential risks and benefits, particularly in patients with haemochromatosis, as vitamin C can enhance non-heme iron absorption and act as a pro-oxidant under certain conditions 1. Some key points to consider when administering subcutaneous vitamin C include:

• Using sodium ascorbate solution (not ascorbic acid) at a concentration of 250-500 mg/mL
• Injecting slowly into the subcutaneous tissue of the abdomen, thigh, or upper arm using a 25-30 gauge needle
• Rotating injection sites to prevent tissue irritation
• Monitoring for any adverse reactions, such as mild burning or stinging during injection It is crucial to weigh the potential benefits of subcutaneous vitamin C against the risks, particularly in patients with haemochromatosis, and to limit the dosage to 500 mg daily, as recommended by the EASL clinical practice guidelines on haemochromatosis 1.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION Administer intramuscularly 1 to 10 mL, depending on condition, species, and body weight. Repeat daily or as indicated by desired response. The FDA drug label does not answer the question.

From the Research

Subcutaneous Vitamin C Administration

The provided studies do not directly address the administration of subcutaneous vitamin C. However, we can look at the information available on vitamin C administration in general:

• The study 2 discusses the pharmacokinetics of vitamin C, comparing oral and intravenous administration. It finds that intravenous administration produces higher peak plasma concentrations of vitamin C.
• The study 3 mentions the use of pharmacological doses of vitamin C (6-16 g/day) in critically ill patients, but does not specify the route of administration.
• The study 4 examines the use of oral vitamin C for preventing and treating the common cold, but does not provide information on subcutaneous administration.

Relevant Information

While there is no direct information on subcutaneous vitamin C administration, we can consider the following points:

• Vitamin C is typically administered orally or intravenously, with intravenous administration producing higher peak plasma concentrations 2.
• The use of subcutaneous administration is not well-studied for vitamin C, and more research is needed to determine its safety and efficacy.
• Other studies, such as 5, discuss the use of subcutaneous administration for other medications, but do not provide information on vitamin C.

Dosage Information

The provided studies do not offer specific guidance on the dosage of subcutaneous vitamin C. However, we can look at the dosages used in other studies:

• The study 2 uses doses of 0.015 to 1.25 g of vitamin C for oral and intravenous administration.
• The study 3 mentions the use of pharmacological doses of 6-16 g/day of vitamin C in critically ill patients.
• The study 4 examines the use of oral vitamin C at doses of 0.2 g or more per day for preventing and treating the common cold.