Time trends and seasonal variation of iodine content in German cow's milk - investigations from Northrhine-Westfalia [Aktuelle Untersuchungen zeitlicher Trends und saisonaler Effekte des Jodgehaltes in Kuhmilch - Untersuchungen aus Nordrhein Westfalen]
Johner S.A.,Forschungsinstitut For Kinderernahrung Fke Dortmund |
von Nida K.,Verbraucherzentrale Nordrhein Westfalen e. V |
Jahreis G.,Friedrich - Schiller University of Jena |
Remer T.,Forschungsinstitut For Kinderernahrung Fke Dortmund
Berliner und Munchener Tierarztliche Wochenschrift | Year: 2012
Cow's milk is one of the most important iodine providers in the human diet. The milk iodine content (MIC) is significantly determined by cattle feeding. The aim of the study was to investigate the longitudinal development of the MIC of German cow's milk during the last years and to assess the current contribution of milk consumption to the population's iodine supply. MIC was analysed by a Cer-Arsenit method after alkaline wet washing in 112 milk samples from nationwide available trademarks (eight samples each were purchased in June and December from 2004 onward to 2010 in the same food markets in the greater Dortmund area). We found an increasing trend of MIC until 2010 (p < 0.005). The mean MIC in 2004/05 was 97 ± 32 μg/l, in 2009/10 it was 110 ± 37 μg/l. This increase was only observable for conventionally (p = 0.0003), and not for organically produced milk (p = 0.7). The MIC of summer milk was about 22 μg/l lower than that of winter milk (p < 0,0001), however, seasonal variation was especially pronounced in organically produced milk. MIC of organically produced milk was in average about 54 μg/l lower than that of conventionally produced milk (p < 0.0001). Thus, the moderate increase of MIC to 110 μg/l on average contributes to the maintainence of the population's iodine supply, whereas the analysed maximum iodine contents of around 170 μg/l do not give reason to expect an excessive iodine intake, even in case of a high Referenzmaterimilk consumption. An appropriate iodine supplementation in foodstuff can be assumed. © 2011 Schlütersche Verlagsgesellschaft mbH & Co. KG.