Ester-C is an advanced form of vitamin C. Amongst the benefits is a neutral pH, which, says Zila, means that the vitamin is gentler on the stomach than traditional forms of the vitamin.
"We have known for years that Ester-C should be better tolerated than regular vitamin C, also known as ascorbic acid. This being confirmed in a double-blind, placebo-controlled human clinical study gives vitamin consumers, a proven reason in addition to the other benefits to take Ester-C," said Douglas Burkett, chairman, CEO and president of Zila.
The study, published in the journal Advances in Natural Therapy (Vol 23, pp. 171-178), reports that 50 volunteers with sensitivity to acidic foods had less epigastric adverse effects than standard vitamin C.
The trial was designed to have an initial three-day supplementation period when the participants would receive either 1000 mg of Ester-C or 1000 mg of ascorbic acid. This was followed by a three-day washout period, and a further three days of the other form of vitamin C than from the initial supplementation period.
The occurrence and severity of gastric side-effects were self-recorded by the participants in diaries.
The researchers, from Germany-based company Analyze & realize ag, found that 56 percent of participants reported 88 mild to moderate epigastric adverse effects. Thirty-three occurred during Ester-C supplementation, and 55 from normal ascorbic acid supplementation.
These results, say the scientists, are significant.
Zila recently announced it has developed and patented a new form of Ester-C said to offer improved antioxidant and anti-carcinogenic potential. Zila said it is nearing the point where the new version will be ready for commercial distribution - although a firm release date has yet to be given.