University of Eastern Finland trusts the analysis results of vitamin D manufacturers

The university is looking into the reasons behind the discrepancy of results obtained using different methods.

The results of a UEF study addressing the vitamin D concentrations of vitamin D products have raised a lot of public discussion and debate. According to the analytical results of the university, several of the 23 products included in the study contained less vitamin D than indicated in the product description. According to Finnish legal requirements, the vitamin D concentration of vitamin D products must be no less than 80 per cent of that indicated in the product description. After the results were publicized, many of the vitamin D product manufacturers and suppliers mentioned in the study have presented analytical certificates showing that their products contain the required amount of vitamin D.

”The analytical certificates presented by vitamin D manufacturers and suppliers have been issued by accredited laboratories, and their results are reliable,” says Professor Tomi-Pekka Tuomainen, the leader of the UEF vitamin D research group.

The researchers regret that the differences between the analytical method used by the university and the accredited method used by the vitamin industry were not explained in sufficient detail when the results of the study were publicized.The university’s analyses were carried out by using the chromatographic HPLC method with electrochemical detection.

”We performed our own analyses to obtain data for research purposes, and our results do not seek to challenge or question those presented in official analysis certificates. In some products, our method yielded the same results as the method used by accredited laboratories. However, this was not the case with regard to all of the products included in the study and we are now looking into the reasons behind this discrepancy,” says Biochemist Tarja Nurmi, PhD.

The university analysed a small number of randomly selected vitamin D products available on the Finnish market. The samples were taken from a single product package representing a single product batch.

”When studying the health effects of vitamin D, it is important to know how much vitamin D people actually get from food and other sources. Dietary supplements constitute a significant source of vitamin D, and this is why we have performed our analyses.”

According to the results of the research group, more than half of the products contained more than 80 per cent of the vitamin D concentration indicated in the product description, and less than half of the products contained less.

The research group regrets the harm the publication of the results has caused to products which fulfil the national legal requirements, and the research group has initiated a cross checking process of the original results. All of the vitamin D products included in the study will be re-analysed using both the university’s original method and the method used by accredited laboratories. Further information on the results will be made available in the near future, as soon as the results are ready.

For further information, please contact:

Professor Tomi-Pekka Tuomainen, tel. +358 40 355 2956, tomi-pekka.tuomainen (at)

Biochemist Tarja Nurmi, PhD,tel. +358 40 355 2965, tarja.nurmi (at)

Requests for interview can also be made via the UEF Communications and Media Relations Office, viestinta (at)

Director of Communications 0405444357, eero.tuomisto (at)

Publishing year: 2012

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