The aim of the study was to compare the profiles of vitamin C serum concentration in healthy volunteers after the single oral administration either in a liposomal or traditional formulation.

The randomized, double-blind, cross-over study was conducted under the supervision of physician on a group of 10 healthy subjects. The volunteers received 1g of vitamin C in a traditional formulation (powder in capsules), and after 14 days of a washout period 1 gram of liposomal formulation (powder in capsules). Venous blood was collected from each participant of the study immediately before the administration of a studied substance and 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours, 8 hours, 10 hours, 24 hours post the administration.

Inclusion Criteria:

• Women and men, 18-65 years old.
• Signed informed consent.
• No injuries or hospitalizations within the last 3 months.
• Refraining from consuming any vitamin C supplements or foods enriched with vitamin C for a period of 72 hours. Limiting excessive consumption of red peppers, parsley (stalks), Brussels sprouts, broccoli, turnip, tomatoes, cabbage, spinach, watercress, citrus fruits, and citrus juices. Not taking acetylsalicylic acid (aspirin, polopiryna, etopiryna) during the study.
• Participants should fast for at least 8-12 hours prior to the administration of the preparations.

Exclusion Criteria:

• Unwilling to give consent.
• Injuries within the last 3 months.
• Cancer (current or past).
• Renal dysfunction (eGFR < 60 ml/min).
• Gastrointestinal disorders (including use of antacids).
• Tobacco use in any form.
• Pregnancy/breastfeeding.
• Patient after organ transplantation, after a stroke, use of anticoagulants, use of immunosuppressants.
• Female patient receiving hormonal therapy (contraception).