Trace nutrients. 4. Iodine in British food.

1. The amounts of iodine in nationally representative samples of prepared and cooked groups of foods and in a wide variety of individual foods and food products were determined colorimetrically. The amounts of erythrosine, a red food colour containing 577 mg I/g were also determined in selected foods and diets by high-performance liquid chromatography. 2. The average British diet was calculated to provide 323 micrograms I/d but only 255 micrograms if two fruit samples containing large amounts of glacé cherries were discounted. Of the total, 92 micrograms was derived from liquid milk. Meat and meat products provided 36 micrograms and cereal products 31 micrograms, but fresh fruits and sugars, vegetables and beverages provided little I. Fish and fish products, though rich in I, contributed only 5% to the total intake. 3. Milk was the most variable as well as the most important individual source of I. Summer milk samples contained 70 micrograms/kg and winter milk 370 micrograms/kg on average. Milk products, including butter and cheese, and eggs were also rich in I. 4. Some processed foods contained erythrosine, particularly glacé cherries and some pink or red confectionery items, biscuits, cherry cake, canned strawberries and luncheon meat. However, none of these are major foods in the average household diet and erythrosine would therefore contribute little more than 10 micrograms I/d to most diets. 5. The average daily intake of I was lower than in similar similar studies in the USA, but was twice the provisional UK recommended intake. This study provides no evidence that I intakes in the UK could be too low or too high for health.U