PlantaCorp, in collaboration with Surya Research Clinics, recently compared the bioavailability of four different supplemental vitamin C forms.
PlantaCorp (Hamburg, Germany), in collaboration with Surya Research Clinics (Bengaluru, India), recently compared the bioavailability of four different supplemental vitamin C forms: PlantaCorp’s 1,000 mg liposomal vitamin C in liquid form (LLA), a competing 1,000 mg liquid liposomal vitamin C (LLB), 1,000 mg of powdered liposomal vitamin C (PL), and 1,000 mg of non-liposomal vitamin C (NL). Forty healthy subjects in their late 20’s participated in the study and were randomly assigned to each product. Oral dosages of vitamin C were administered to fasting subjects, and blood was collected at baseline, 2, 4, 6, 8, 10, 12, 16, 20, and 24 hours after administration. Surya Research Clinics analyzed the blood for plasma ascorbic acid (AA) via high-performance liquid chromatography (HPLC).
Results showed that LLA was 1.92 times more bioavailable than LLB, 21.64 times more bioavailable than PL, and 12.17 times more bioavailable than NL. While area under the curve (AUC) values showed no statistical significance between LLA and LLB for bioavailability, compared to LLB, the LLA group had significantly higher levels of plasma AA at 10, 12, 16, 20 hours. Compared to PL, the LLA group had higher plasma levels of AA at every point from 4 to 24 hours. The same was true when compared to NL.
LLB was 11.26 times and 6.34 time more bioavailable to PL and NL, respectively, reaching significantly higher AA plasma levels at every point between 4 and 16 hours after supplementation. NL was 1.78 times more bioavailable than PL, but AUC was not significant between the two groups, and there were no significant interactions between the treatment and time of blood draw on plasma AA levels between the two groups.
Liposomes have been shown to increase the bioavailability of various nutrients, including vitamin C. Vitamin C’s bioavailability is particularly affected at higher doses.
“Vitamin C is bioavailable, but only to a certain extent. Lower doses, around 200 mg can be well-absorbed, however, in higher doses (>500 mg) its absorption is quite limited by transporters at the enterocyte, and this gets worse the higher the dose,” says Allison Labyk, head of product management at ActiNovo, PlantaCorp’s sister company. “Because the absorption pathway into the intestine for liposomes is independent of the active ingredient, they’re able to deliver almost all of the vitamin C directly to the enterocyte and bypass the typically limiting absorption mechanisms of the body.”
When compared to non-liposomal vitamin C, both the liquid forms performed significantly better, while the powdered liposomal vitamin C underperformed compared to even non-liposomal vitamin C. “From our knowledge, the process to dry liposomes is quite expensive and time consuming. Done right, it can be effective, but we believe its highly possible that the process can destroy the liposomes, creating more of just a phospholipid/vitamin C mixture in the capsule,” says Labyk. “Liquid liposomes are ideal, because water is a crucial element in the formation of liposomes. Keeping the product in liquid form allows the liposomes to maintain their original shape and undergo less processing that can ultimately lead to the degradation of the liposomes.”
The differences between the two liquid liposomal products may likely be attributed to a difference in production processes. “PlantaCorp uses patented LipoSone technology that involves ultra-sonication at extremely specific pattern of wavelength, amplitude, frequency in order to create our liposomes,” explains Labyk. “Furthermore, we think that the amount and quality of phospholipids is crucial to building high quality liposomes. All of these points allow us to create an optimized particle size which is ideal for this application.”
While there were no significant differences between the two liquid liposomal products, Labyk is encouraged by the higher plasma ascorbic acid levels in subjects taking PlantaCorp’s vitamin C. “[PlantaCorp’s] liposomal vitamin C was significantly higher than the non-liposomal product at hours 20 and 24, while the competitor’s liquid liposomal product had already reached back to baseline at this point. This shows that perhaps [PlantaCorp’s] product was still at work, while the rest had finished their job, so to speak,” explains Labyk. “I think it’s possible that had we conducted this study for a longer period of time, the [PlantaCorp] product may have had a higher AUC after all. In general, I think the higher sustained levels of plasma ascorbic acid bode well for the product, showing high exposure to the vitamin C overall. In any case, more robust studies with a larger sample size are necessary to look deeper into these differences.”