Vitamin C:
Ascorbic Acid and Ascorbyl Palmitate Compared
By VRP Staff
Although ascorbyl palmitate, the fat-soluble form of vitamin C, has been utilized in nutritional supplements for more than a decade, very little research
has been conducted to determine the bioavailability of ascorbyl palmitate as a source of vitamin C. Now, new light has been placed on ascorbic acids fat-soluble brother. A recent study has examined the potency of ascorbyl palmitate as a source of vitamin C in reversing scurvy in guinea pigs, as well as the effect of ascorbyl palmitate supplementation on plasma and urine levels of vitamin C in humans. In both cases, ascorbyl palmitate was compared with water-soluble ascorbic acid.
In the case of reversing scurvy in guinea pigs, ascorbyl palmitate was found to be effective. It was approximately 50 percent as potent as ascorbic acid in preventing
weight-loss associated with scurvy, although tissue levels of vitamin C were not significantly different between the ascorbic acid and ascorbyl palmitate group. The reason
for this seeming contradiction is probably related to the design of the
study. The period of time followed during vitamin C repletion was only ten days, an amount of time possibly too short to fully quantify the long-term effects of the different supplemental forms of vitamin C. Changes in bone structure, a common pathology of scurvy, were equally reversed by both forms of vitamin C.
These authors also conducted a study of ascorbyl palmitate in humans. They examined the effects of both a single dose and two-week supplementation (2 grams of vitamin C) of both ascorbic acid and ascorbyl palmitate on plasma and urine levels of vitamin C. After a single two-gram dose, ascorbyl palmitate did not appear in the plasma vitamin C pool as rapidly as ascorbic acid, and this amounted to a 20% difference in the eight-hour, post-dose period. By 24 hours after a single dose, plasma vitamin C values were similar for both forms of vitamin C.
Following 2 weeks of supplementation at 2 grams a day, plasma vitamin C levels were slightly higher for ascorbyl palmitate as compared to ascorbic acid. Mean 24-hour urinary excretion, however, was 33% LOWER following ascorbyl palmitate supplementation, indicating better utilization of ascorbyl palmitate. These results led the authors to conclude that ascorbyl palmitate, ...can be considered an effective source of plasma vitamin C in man and, compared to water-soluble ascorbic acid, may be less easily lost in urine.
Interestingly, these authors also referenced research that compared ascorbic acid and ascorbyl palmitate as antitumor agents in animals. Not only was ascorbyl palmitate more than 30 times more potent than ascorbic acid as a topical antitumor promoter, but ascorbyl palmitate was effective when added to the diet while ascorbic acid was not. Surprisingly, the antioxidant activity of ascorbyl palmitate did not seem to be responsible for its antitumor activity. Thus it appears that ascorbyl palmitate supplementation is complimentary to traditional ascorbic acid supplementation, both as a source of vitamin C and for its potentially unique properties.
Based on this research, we would have to agree with the authors conclusion that ascorbyl palmitate should be used more extensively in the food industry as a source of vitamin C, as well as a preservative.yes> Not only is it a stable source of vitamin C that would improve the nutritional value of food, but it is also an excellent antioxidant that would help prevent oxidation and improve product shelf life.
Reference
C.S. Johnston, W.C. Monte, R.S. Bolton, et al. Nutrition Research. 1994; 14: 1465-1471.
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