Chapter 45 - Assessment of Iodine Intake and Iodine Status in Vegans

Abstract

This chapter explores the major sources of iodine in the vegan diet, and the assessment of iodine intake and status in vegans using different dietary and biochemical techniques. The iodine concentration in foods of all types varies considerably due to a number of factors, such as soil composition, animal breeding, climate, and other environmental variables. Moreover, the amount of iodine from each food depends on the source, preparation, processing and volume consumed. The use of dietary records and food tables may be considered inappropriate to reasonably estimate iodine intake in groups of individuals consuming unconventional foods not listed, or inconsistently listed, in food tables. Although the duplicate portion technique may be considered the best method for the assessment of trace element intake, it is not always practical to determine iodine intake using this method of dietary assessment. The techniques used in the assessment of iodine intake are indicative of the reliability of the results, although dietary analysis used in conjunction with biochemical measurements may reduce the margin of error. The measurement of urinary iodine excretion may be used as an indicator of iodine intake and deficiency. Establishing links between actual dietary iodine intake and iodine deficiency disorders relies on the availability of precise techniques to enable accurate estimation of nutritional intake. However, the evaluation of iodine intake is difficult, due to wide variations in the iodine content of food; hence, obtaining an accurate assessment is not possible with food composition tables. This is particularly pertinent to vegans who consume a variety of unconventional foods not listed, or inconsistently listed, in such tables.