The university will re-analyse the supplements acquired from chemists, shops and online stores for a second time in two weeks in order to validate the D vitamin levels reported in the previous study.
The supplements will be analysed at the University of Eastern Finland using the same methodology. They will also be analysed in other independent accredited laboratories this time around.
Professor Tomi-Pekka Tuomainen said the tests will be conducted over the next few weeks.
Tuomainen said that the university’s measurements were accurate enough to determine the vitamin levels, although pre-treatment of the pills may also affect the results.
The professor found it surprising that some of the university results corresponded with those of the supplement manufacturers, while results for other supplements diverged. Tuomainen wondered if the supplements reacted differently under the analysis conducted at the university.
Some supplement manufacturers are yet to provide the university with their own reports of vitamin levels.
“There was variation within the results. The biggest incongruence between a manufacturer’s report and university findings was about 30 percent,” Tuomainen noted.
The vitamin levels may also be affected by the supplements' storage conditions and storage time.
