Vitamin C Bioequivalence from Gummy and Caplet Sources in Healthy Adults: A Randomized-Controlled Trial

Abstract

Background: The efficacy of Vitamin C (L-ascorbic acid) supplementation can be assessed by uptake into the blood and retention in leukocytes. Vitafusion® Power C gummy is an alternative vitamin C source which may exhibit similar bioavailability to comparator caplets.

Objective: The objective of this study was to evaluate the bioequivalence of vitamin C from a vitafusion® Power C gummy formulation and a comparator caplet in healthy adults.

Methods: Thirty healthy men and women, 34.0 ± 11.4 years of age and Body Mass Index (BMI) 24.5 ± 3.6 kg/m² completed the randomized examiner-blind, comparator controlled, cross-over trial with two sequences: gummy (1000 mg) to caplet (1000 mg) or caplet to gummy. Intake of foods fortified with Vitamin C was restricted 7 days prior to each dosing. Blood samples were collected pre-dose and at 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12 and 24 h post-dose for plasma and leukocytes; and urine was collected pre-dose and between 0-2, 2-4, 4-8, 8-12 and 12-24 h post-dose for L-ascorbic acid analysis.

Results: Vitafusion® Power C gummy and comparator caplet demonstrated similar plasma absorption profiles as there were no significant differences in plasma L-ascorbic acid total Area Under the Curve (AUC)_0-24h, and T_max between gummy and caplet. The caplet did elicit a significantly higher C_max than the gummy (p < 0.05), however, the difference was numerically small. Leukocyte L-ascorbic acid total AUC_0-24h and C_max were not significantly different between gummy and caplet, however T_max of the gummy group was significantly longer (p = 0.012). Urinary L-ascorbic acid levels were also not significantly different between gummy and caplet. There were no serious adverse events and safety parameters remained within normal clinical range for both products.

Conclusion: Vitafusion® Power C gummy exhibited similar Vitamin C absorption and bioavailability to a comparator caplet in healthy adults and were considered bioequivalent.

Keywords:

• Vitamin C
• L-ascorbic acid
• vitafusion^® Power C gummy
• absorption
• bioavailability
• bioequivalence
• multivitamin

Acknowledgments

H. K. Z., W. H., A. W., and A. G. contributed to the inception and design of the study along with M. E., and N. G. All authors contributed to the writing and editing of the manuscript and approved the final version. We would also like to acknowledge the input of Mohammed Marzuk in the interpretation of urinary L-ascorbic acid amounts.

Declaration of conflict of interest

Church & Dwight Co., Inc., owns vitafusion® Power C Gummy and provided funding. H. Kelly Zhang, William Hooper, Andrew Wong, and Annahita Ghassemi are employees of Church & Dwight Co., Inc. These affiliations did not affect the interpretation of the results.