British Journal of Nutrition

Iodine in Brirish foods and diets

Iodine in British foods and diets

Susan M. Leea1, Janet Lewisa1, David H. Bussa1*, Gillian D. Holcombea2 and Paul R. Lawrancea2

a1 Ministry of Agriculture, Fisheries and Food, Nobel House, I7 Smith Square, London SWIP 3JR

a2 Laboratory of the Government Chemist, Queens Road, Teddington, Middlesex TWll OLY


Levels of I were determined in selected foods and dietary supplements, and in samples of the British ‘Total Diet’. The average concentration of I in British milk collected in thirteen areas on four occasions during 1990 and 1991 was 150 μg/kg (range 40–310 μg/kg), compared with 230 μg/kg in 1977–79. No difference was found between skimmed and whole milk. Winter milk contained 210 μg/kg while summer milk contained 90 μg/kg. Regional differences were less pronounced than seasonal differences. Levels in fish and fish products were between 110 and 3280 μg/kg. Edible seaweed contained I levels of between 4300 and 2660000 μg/kg. Kelp-based dietary supplements contained I at levels that would result in a median intake of 1000 μg if the manufacturers' recommended maximum daily dose of the supplement was taken, while other I-containing supplements contained a median level of 104 μg in the manufacturers' maximum recommended daily dose. Intake of I, as estimated from the Total Diet Study, was 173 μg/d in 1985 (277 μg if samples with very high I contents were included) and 166 μg/d in 1991. These levels are above the UK reference nutrient intake of 140 μg/d for adults but well below the Joint Expert Committee on Food Additives provisional maximum tolerable intake of 1000 μg/d.

(Received September 29 1993)

(Accepted January 14 1994)


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