Milk as an essential source of iodine in Latvian population

Abstract

Milk and dairy products are studied as alternative iodine sources, because salt iodisation is controversial due to high salt consumption leading to cardiovascular diseases. However, the iodine concentration in milk markedly varies. This study evaluated the iodine concentration in cow's milk available in the Latvian market. Iodine and fat concentration was analysed with a spectrophotometer "Varian Cary 50" based ISO 2446:2008 in 20 milk samples. Data from the Central Statistical Bureau and survey among pregnant women were used to analyse milk product consumption and its impact on iodine status. Average iodine concentration in milk samples was 457.6 (179.6) μg/L, winter samples had a higher concentration of iodine than summer samples: 563.4 (329.6) μg/L and 469.2 (162.0) μg/L, but this is not statistically significant p < 0.05. Iodine concentration in skimmed milk was 490 μg/L, milk with the reduced fat content 501.7 (174.8) μg/L, and whole milk - 422.6 (192.1)1 μg/L. Milk consumption decreased from 2002 to 2014, while yogurt and cheese consumption increased. Higher consumption of milk and milk products was related to higher urinary iodine concentration ρ = 0.115; p = 0.003. Milk and milk products are an important iodine source in Latvia and their consumption should be promoted.